3660 lines
118 KiB
Text
3660 lines
118 KiB
Text
.nr *% \n(%#u+7u
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.ds NR "\f2nroff\fP
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.ds TR "\f2troff\|\fP
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.ds Tr \f2Troff\|\fP
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.ds Nr \f2Nroff\fP
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. \" CW - constant width font not from -ms
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.de T&
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.X "END US
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.X "US T&
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..
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.de CW
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.nr PQ \\n(.f
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.if \\n(.$=0 .ft CW
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.if \\n(.$>0 \%\&\\$3\f(CW\\$1\\f\\n(PQ\\$2
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..
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.de BI
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.nr PQ \\n(.f
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.if \\n(.$=0 .ft 4
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.if \\n(.$>0 \%\&\\$3\f2\\$1\\f\\n(PQ\\$2
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..
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.de UC
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\\$3\s-2\\$1\s+2\\$2
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..
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.am NH
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.nr p \\np+1
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.nr s 0 1
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..
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.fp 4 BI LucidaSansI
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.bd 4 3
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.de sc
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.LP
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\f4\\np.\\n+s.\ \ \\$1\f1\0
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..
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.de bt
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.SP .25
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.LP
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.NE 2.1
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.ta 1.5i 2.5i 3.5i 4.5i
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\\$1 \\$2 \\$3 \\$4
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.IP "" 0.8i
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....br
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\\$5
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..
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.
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.
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.
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.
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.
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.
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.
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.TL
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Troff User's Manual
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.AU
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Joseph F. Ossanna
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Brian W. Kernighan
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.sp
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bwk@research.bell-labs.com
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.EQ
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delim @@
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define cw % "\&" font CW %
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.EN
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.SH
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Introduction
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.PP
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\*(Tr and \*(NR are text processors
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that format text for typesetter- and
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typewriter-like terminals, respectively.
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They accept lines of text interspersed with lines of
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format control information and
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format the text into a printable, paginated document
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having a user-designed style.
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\*(Tr and \*(NR offer
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unusual freedom in document styling:
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arbitrary style headers and footers;
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arbitrary style footnotes;
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multiple automatic sequence numbering for paragraphs, sections, etc;
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multiple column output;
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dynamic font and point-size control;
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arbitrary horizontal and vertical local motions at any point;
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and
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a family of automatic overstriking, bracket construction, and
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line-drawing functions.
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.
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.de TL
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.LP
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.ce
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.ps +2
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.ft B
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..
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.
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.PP
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.I Troff
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produces its output in a device-independent form,
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although parameterized for a specific device;
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\*(TR output must be processed by a driver for that
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device to produce printed output.
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.PP
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\*(Tr and \*(NR are highly compatible with each other and it is almost always
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possible to prepare input acceptable to both.
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Conditional input is provided to enable
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the user to embed input expressly destined for either program.
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\*(Nr can prepare output directly for a variety of terminal types and
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is capable of utilizing the full resolution of each terminal.
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\*(Nr is the same program as \*(TR; in fact, on Plan 9
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\*(NR is a shell script that calls \*(TR with the
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.CW -N
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argument.
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.SH
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Background to the Plan 9 Edition
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.PP
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The primary change to \*(TR and \*(NR for Plan 9 is
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support of the Unicode Standard, which was added during
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1992 and 1993. There are two results. First, there is much
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less need for the myriad of two-character names that are so
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much a part of \*(TR lore; in Plan 9, for example, one naturally uses the
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Unicode character ½ instead of \*(TR\|'s
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.CW \\e(12 .
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Second, the output device, though called
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.CW utf ,
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is almost always a form of PostScript printer;
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the panoply of special drivers for different typesetters
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has largely disappeared.
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Unfortunately, not all PostScript printers can cope
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with Unicode characters, so there remains a need for
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programs that synthesize PostScript characters from bitmaps;
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this is especially true for Asian languages.
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.SH
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Background to the Second Edition
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.PP
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\*(Tr
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was originally written by the late Joe Ossanna
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in about 1973, in assembly language for the
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.UC PDP -11,
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to drive the Graphic Systems CAT typesetter.
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It was rewritten in C around 1975,
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and underwent slow but steady evolution until
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Ossanna's death late in 1977.
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.PP
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In 1979, Brian Kernighan
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modified
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\*(TR
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so that it would produce output for a variety of typesetters,
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while retaining its input specifications.
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Over the decade from 1979 to 1989,
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the internals
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have been modestly revised,
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though much of the code remains as it was when Ossanna wrote it.
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.PP
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\*(Tr
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reads parameter files
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each time it is invoked, to
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set values for machine resolution,
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legal type sizes and fonts, and character names,
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character widths
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and the like.
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\*(Tr
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output is
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.UC ASCII
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characters
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in a simple language
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that describes where each character is to be placed
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and in what size and font.
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A post-processor must be written for each device
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to convert this typesetter-independent language
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into specific instructions for that device.
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.PP
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The output language contains information that was not readily
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identifiable in the older output.
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In the newer language, the beginning of each page, line, and word
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is marked,
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so post-processors can do device-specific optimizations
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such as sorting the data vertically or printing it boustrophedonically,
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independent of
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\*(TR.
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.PP
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Capabilities for graphics have been added:
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\*(TR
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recognizes commands for drawing diagonal lines,
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circles, ellipses, circular arcs,
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and quadratic B-splines.
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There are also ways to pass arbitrary information to the output,
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unprocessed by
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\*(TR.
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.PP
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A number of limitations have been eased or eliminated.
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A document may have an arbitrary number of fonts on any page
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(if the output device permits it, of course).
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Fonts may be accessed merely by naming them;
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``mounting'' is no longer necessary.
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There are no limits on the number of characters.
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\H'8'Character height\H'10' and \S'-1'sl\S'0'a\S'1'nt\S'0' may be set
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independently of width.
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.PP
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The remainder of this document contains a description of
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usage and command-line options;
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a summary of requests, escape sequences, and pre-defined number registers;
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a reference manual;
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tutorial examples;
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and a list of commonly-available characters.
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.SH
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Acknowledgements
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.PP
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Joe Ossanna's
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\*(TR
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remains a remarkable accomplishment.
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For more than twenty years, it has proven a robust tool,
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taking unbelievable abuse from a variety of preprocessors
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and being forced into uses that were never conceived of
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in the original design,
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all with considerable grace under fire.
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.PP
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Recent versions of \*(TR have profited from
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significant code improvements by
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Jaap Akkerhuis, Dennis Ritchie, Ken Thompson, and Molly Wagner.
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UTF facilities owe much to Jaap Akkerhuis.
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Andrew Hume, Doug McIlroy, Peter Nelson and Ravi Sethi made valuable suggestions on the manual.
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I fear that the remaining bugs are my fault.
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.sp 100
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.BP
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.TL
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Usage
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.SP
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.PP
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\*(Tr or \*(NR is invoked as
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.P1
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troff \fIoptions files\fP
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nroff \fIoptions files\fP
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.P2
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where @options@ represents any of a number of option arguments
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and @files@ represents the list of files containing the document
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to be formatted.
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An argument consisting of a single minus
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.CW - ' `
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represents standard input.
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If no filenames are given input is taken from the standard input.
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The options, which may appear in any order so long as they appear
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before the files, are:
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.TS
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center;
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lfCW lw(4.5i).
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-m@name@ T{
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Read the macro file
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@cw /sys/lib/tmac. name@
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before the input @files@.
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T}
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-T@name@ T{
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Specifies
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the type of the output device.
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Specific devices are site-dependent.
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For
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\*(TR,
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the most useful name is
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.CW utf .
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For
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\*(NR,
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useful names include
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@cw "37"@ for the (default) Model 37 Teletype,
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@cw lp@ for ``dumb'' line printer terminals (no half-line motions,
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no reverse motions),
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and @cw think@ for the HP ThinkJet printer.
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T}
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-i T{
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Read standard input after the input files are exhausted.
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T}
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-o@list@ T{
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Print only pages whose page numbers appear in @list@,
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which consists of comma-separated numbers and number ranges.
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A number range has the form @N-M@
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and means pages @N@ through @M@;
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a initial @-N@ means
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from the beginning to page @N@; and a final @N-@ means
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from @N@ to the end.
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T}
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-n@N@ T{
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Number first generated page @N@.
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T}
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-r@aN@ T{
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Set number register @a@ (one-character) to @N@.
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T}
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-s@N@ T{
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Stop every @N@ pages.
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\*(Nr will halt prior to every @N@ pages (default @N=1@)
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to allow paper loading or
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changing, and will resume upon receipt of a newline.
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\*(Tr will include a ``pause'' code every @N@ pages;
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its meaning, if any, depends on the output device.
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T}
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-u@N@ T{
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Set amount of emboldening for the
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.CW bd
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request to @N@.
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T}
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-F@path@ T{
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Look in directory @path@ for font information;
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the defaults are
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.CW /sys/lib/troff/font
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and
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.CW /sys/lib/troff/term
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for \*(TR
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and \*(NR respectively.
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T}
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.sp .5
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T{
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\*(TR Only
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T}
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-a T{
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Send a printable approximation
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of the results to the standard output.
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T}
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.sp .5
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T{
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\*(NR Only
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T}
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-e T{
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Produce equally-spaced words in adjusted
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lines, using full terminal resolution.
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T}
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-h T{
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Use tabs instead of spaces
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to speed up printing.
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T}
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-q T{
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Invoke the simultaneous input-output mode of the @cw rd@ request.
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T}
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.TE
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.PP
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Each option is a separate argument;
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for example,
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.P1
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troff -Tutf -ms -mpictures -o4,6,8-10 \f2file1 file2\fP
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.P2
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requests formatting of pages 4, 6, and 8 through 10 of a document contained in the files
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named \f2file1\fP and \f2file2\fP,
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specifies the output in UTF,
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and invokes the macro packages
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.CW -ms
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and
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.CW -mpictures .
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.PP
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Various pre- and post-processors are available for use with \*(NR and \*(TR.
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These include the equation preprocessor
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.I eqn
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(for \*(TR only),
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the table-construction preprocessor
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.I tbl ,
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and
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.I pic
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and
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.I grap
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for various forms of graphics.
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.sp 100
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.BP
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.TL
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Request Summary
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.PP
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In the following table,
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the notation @+- N@ in the
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.BI "Request Form
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column means that the forms @N@, @+N@, or @-N@ are permitted,
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to set the parameter to @N@, increment it by @N@, or decrement it by @N@,
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respectively.
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Plain @N@ means that the value is used to set the parameter.
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.BI "Initial Values
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separated by
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.CW ;
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are for
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\*(TR
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and
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\*(NR
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respectively.
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In the
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.BI Notes
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column,
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.TS
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center;
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c lw(4.5i).
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B T{
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Request normally causes a break.
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The use of
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.CW ' \&
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as control character (instead of
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.CW . )\&
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suppresses the break function.
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T}
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D T{
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Mode or relevant parameters associated with current diversion level.
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T}
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E T{
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Relevant parameters are a part of the current environment.
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T}
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O T{
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Must stay in effect until logical output.
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T}
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P T{
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Mode must be still or again in effect at the time of physical output.
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T}
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T T{
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\*(TR only; no effect in \*(NR.
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T}
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@bold v@, @bold p@, @bold m@, @bold u@ T{
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Default scale indicator; if not specified, scale indicators are ignored.
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T}
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.TE
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.sp
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.tr &.
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.ps 9
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.vs 11
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.nr z 0 1
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.TS
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lf2 lf2 lf2 lf2 lf2
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lf2 lf2 lf2 lf2 lf2
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lfCW l l l l.
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Request Initial If No
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Form Value Argument Notes Explanation
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.sp .5
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.T&
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lf3 s s s s.
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\\n+z. General Information
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.sp .5
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.T&
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lf3 s s s s
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lfCW l l l l.
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\\n+z. Font and Character Size Control
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.sp .5
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&ps @+- N@ 10 point previous E,T Point size; also @cw "\es" +- N@.
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&ss @N@ 12/36\fBm\fP ignored E,T Space-character size set to @N/36@ em.
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&cs @ F~N~ M@ off - P,T Constant character space (width) mode (font @F@).
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&bd @F~N@ off - P,T Embolden font @F@ by @N-1@ units.
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&bd S@~F~N@ off - P,T Embolden Special Font when current font is @F@.
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&ft@~F@ Roman previous E Change to font @F@; also @cw "\ef" x@, @cw "\ef(" xx@, @cw "\ef" N@.
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&fp@~N~F~L@ R,I,B,...,S ignored - Mount font named @F@ on physical position @N <= 1@;
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long name is @L@ if given.
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.sp .5
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.T&
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lf3 s s s s
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lfCW l l l l.
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\\n+z. Page Control
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&pl @+- N@ 11i 11i @bold v@ Page length.
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&bp @+- N@ @N=1@ - B,@bold v@ Eject current page; next page number @N@.
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&pn @+- N@ @N=1@ ignored - Next page number @N@.
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&po @+- N@ 1i; 0 previous @bold v@ Page offset.
|
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&ne @N@ - @N=1 roman v@ D,@bold v@ Need @N@ vertical space.
|
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&mk @R@ none internal D Mark current vertical place in register @R@.
|
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&rt @+- N@ none internal D,@bold v@ Return (upward only) to marked vertical place.
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.sp .5
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.T&
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lf3 s s s s
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lfCW l l l l.
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\\n+z. Text Filling, Adjusting, and Centering
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&br - - B Break.
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&fi fill - B,E Fill output lines.
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|
&nf fill - B,E No filling or adjusting of output lines.
|
|
&ad @c@ adj, both adjust E Adjust output lines with mode @c@; @c = cw l , cw r , cw c , cw b , none@
|
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&na adjust - E No output line adjusting.
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&ce @N@ off @N=1@ B,E Center next @N@ input text lines.
|
|
.sp .5
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.T&
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lf3 s s s s
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lfCW l l l l.
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\\n+z. Vertical Spacing
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&vs @N@ 12p; 1/6i previous E,@bold p@ Vertical baseline spacing (@V@).
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&ls @N@ @N=1@ previous E Output @N-1@ @bold v@'s after each text output line.
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&sp @N@ - @N=1@v B,@bold v@ Space vertical distance @N@ in either direction.
|
|
&sv @N@ - @N=1@v @bold v@ Save vertical distance @N@.
|
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&os - - - Output saved vertical distance.
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&ns space - D Turn no-space mode on.
|
|
&rs - - D Restore spacing; turn no-space mode off.
|
|
.sp .5
|
|
.T&
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lf3 s s s s
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lfCW l l l l.
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|
\\n+z. Line Length and Indenting
|
|
&ll @+- N@ 6.5i previous E,@bold m@ Line length.
|
|
&in @+- N@ @N=0@ previous B,E,@bold m@ Indent.
|
|
&ti @+- N@ - ignored B,E,@bold m@ Temporary indent.
|
|
.sp .5
|
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.ne 2.1
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.T&
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lf3 s s s s
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lfCW l l l l.
|
|
\\n+z. Macros, Strings, Diversion, and Position Traps
|
|
&de @xx~yy@ - @.yy= cw ".."@ - Define or redefine macro @xx@; end at call of @yy@.
|
|
&am @xx~yy@ - @.yy= cw ".."@ - Append to a macro.
|
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&ds @xx~string@ - ignored - Define a string @xx@ containing @string@.
|
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&as @xx~string@ - ignored - Append @string@ to string @xx@.
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&rm @xx@ - ignored - Remove request, macro, or string.
|
|
&rn @xx~yy@ - ignored - Rename request, macro, or string @xx@ to @yy@.
|
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&di @xx@ - end D Divert output to macro @xx@.
|
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&da @xx@ - end D Divert and append to @xx@.
|
|
&wh @N~xx@ - - @bold v@ Set location trap; negative is w.r.t. page bottom.
|
|
&ch @xx~N@ - - @bold v@ Change trap location.
|
|
&dt @N~xx@ - off D,@bold v@ Set a diversion trap.
|
|
&it @N~xx@ - off E Set an input-line count trap.
|
|
&em @xx@ none none - End macro is @xx@.
|
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.sp .5
|
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.T&
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lf3 s s s s
|
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lfCW l l l l.
|
|
\\n+z. Number Registers
|
|
&nr @R~+- N~M@ - @bold u@ Define and set number register @R@;
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|
auto-increment by @M@.
|
|
&af @R~c@ arabic - - Assign format to register @R@ (@c= cw "1" , cw i , cw I , cw a , cw A@).
|
|
&rr @R@ - - - Remove register @R@.
|
|
.sp .5
|
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.T&
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lf3 s s s s
|
|
lfCW l l l l.
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|
\\n+z. Tabs, Leaders, and Fields
|
|
&ta@~Nt~. . .@ 0.5i; 0.8n none E,@bold m@ Tab settings; left-adjusting, unless
|
|
@t= cw R@ (right), @cw C@ (centered).
|
|
&tc@~c@ none none E Tab repetition character.
|
|
&lc@~c@ @cw "."@ none E Leader repetition character.
|
|
&fc@~a~b@ off off - Set field delimiter @a@ and pad character @b@.
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Input and Output Conventions and Character Translations
|
|
&ec@~c@ \e \e - Set escape character.
|
|
&eo on - - Turn off escape character mechanism.
|
|
&lg@~N@ on; - on T Ligature mode on if @N>0@.
|
|
&ul@~N@ off @N=1@ E Underline (italicize in \*(TR\^) @N@ input lines.
|
|
&cu@~N@ off @N=1@ E Continuous underline in \*(NR; in \*(TR, like @cw ul@.
|
|
&uf@~F@ Italic Italic - Underline font set to @F@ (to be switched to by @cw ul@).
|
|
&cc@~c@ @cw .@ @cw .@ E Set control character to @c@.
|
|
&c2@~c@ @cw "'"@ @cw "'"@ E Set no-break control character to @c@.
|
|
&tr@~abcd....@ none - O Translate @a@ to @b@, etc., on output.
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s.
|
|
\\n+z. Local Horizontal and Vertical Motions, and the Width Function
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s.
|
|
\\n+z. Overstrike, Bracket, Line-drawing, Graphics, and Zero-width Functions
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Hyphenation.
|
|
&nh hyphenate - E No hyphenation.
|
|
&hy@~N@ hyphenate hyphenate E Hyphenate; @N =@ mode.
|
|
&hc@~c@ @cw "\e%"@ @cw "\e%"@ E Hyphenation indicator character @c@.
|
|
&hw@~word~. . .@ ignored - Add words to hyphenation dictionary.
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Three-Part Titles.
|
|
&tl@~'l'c'r'@ - - Three-part title; delimiter may be any character.
|
|
&pc@~c@ @cw %@ off - Page number character.
|
|
<@~+- N@ 6.5i previous E,@bold m@ Length of title.
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Output Line Numbering.
|
|
&nm@~+- N^M^S^I@ off E Number mode on or off, set parameters.
|
|
&nn@~N@ - @N=1@ E Do not number next @N@ lines.
|
|
.sp .5
|
|
.ne 2
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Conditional Acceptance of Input
|
|
&if@~c~any@ - - If condition @c@ true, accept @any@ as input;
|
|
for multi-line, use @cw "\e{" any cw "\e}"@.
|
|
&if !@c~any@ - - If condition @c@ false, accept @any@.
|
|
&if@~N~any@ - @bold u@ If expression @N > 0@, accept @any@.
|
|
&if !@N~any@ - @bold u@ If expression @N <= 0@ [sic], accept @any@.
|
|
&if@~ 's1 's2 '~any@ - - If string @s1@ identical to @s2@, accept @any@.
|
|
&if !@ 's1 's2 '~any@ - - If string @s1@ not identical to @s2@, accept @any@.
|
|
&ie@~c~any@ - @bold u@ If portion of if-else; all above forms (like @cw "if"@).
|
|
&el@~any@ - - Else portion of if-else.
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Environment Switching
|
|
&ev@~N@ @N=0@ previous - Environment switch (push down).
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Insertions from the Standard Input
|
|
&rd@~prompt@ - @prompt@=\s-1BEL\s+1 - Read insertion.
|
|
&ex - - - Exit.
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Input/Output File Switching
|
|
&so@~filename@ - - Switch source file (push down).
|
|
&nx@~filename@ end-of-file - Next file.
|
|
&sy@~string@ - - Execute program @string@. Output not interpolated.
|
|
&pi@~string@ - - Pipe output to program @string@.
|
|
&cf@~filename@ - - Copy file contents to \*(TR output.
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s
|
|
lfCW l l l l.
|
|
\\n+z. Miscellaneous
|
|
&mc@~c~N@ - off E,@bold m@ Set margin character @c@ and separation @N@.
|
|
&tm@~string@ - newline - Print @string@ on terminal (standard error).
|
|
&ab@~string@ - newline - Print @string@ on standard error, exit program.
|
|
&ig@~yy@ - @.yy= cw ".."@ - Ignore input until call of @yy@.
|
|
&lf@~N ~f@ - - Set input line number to @N@ and filename to @f@.
|
|
&pm@~t@ - all - Print macro names, sizes; if @t@ present, print total.
|
|
&fl - - B Flush output buffer.
|
|
.sp .5
|
|
.T&
|
|
lf3 s s s s.
|
|
\\n+z. Output and Error Messages
|
|
.sp .5
|
|
\\n+z. Output Language
|
|
.sp .5
|
|
\\n+z. Device and Font Description Files
|
|
.TE
|
|
.br
|
|
.nr zz 9
|
|
.de cl
|
|
.ie \\n+(cl<\n(zz \{\
|
|
. po +\\n(.lu/\n(zzu
|
|
. rt\}
|
|
.el \{.po 1i\}
|
|
..
|
|
.nr cl 0 1
|
|
.di zz
|
|
.ta .45iR
|
|
... was .35
|
|
.nf
|
|
.ps 9
|
|
.vs 10.5
|
|
\f(CWab\fP 20
|
|
\f(CWad\fP 4
|
|
\f(CWaf\fP 8
|
|
\f(CWam\fP 7
|
|
\f(CWas\fP 7
|
|
\f(CWbd\fP 2
|
|
\f(CWbp\fP 3
|
|
\f(CWbr\fP 4
|
|
\f(CWc2\fP 10
|
|
\f(CWcc\fP 10
|
|
\f(CWce\fP 4
|
|
\f(CWcf\fP 19
|
|
\f(CWch\fP 7
|
|
\f(CWcs\fP 2
|
|
\f(CWcu\fP 10
|
|
\f(CWda\fP 7
|
|
\f(CWde\fP 7
|
|
\f(CWdi\fP 7
|
|
\f(CWds\fP 7
|
|
\f(CWdt\fP 7
|
|
\f(CWec\fP 10
|
|
\f(CWel\fP 16
|
|
\f(CWem\fP 7
|
|
\f(CWeo\fP 10
|
|
\f(CWev\fP 17
|
|
\f(CWex\fP 18
|
|
\f(CWfc\fP 9
|
|
\f(CWfi\fP 4
|
|
\f(CWfl\fP 20
|
|
\f(CWfp\fP 2
|
|
\f(CWft\fP 2
|
|
\f(CWhc\fP 13
|
|
\f(CWhw\fP 13
|
|
\f(CWhy\fP 13
|
|
\f(CWie\fP 16
|
|
\f(CWif\fP 16
|
|
\f(CWig\fP 20
|
|
\f(CWin\fP 6
|
|
\f(CWit\fP 7
|
|
\f(CWlc\fP 9
|
|
\f(CWlg\fP 10
|
|
\f(CWlf\fP 20
|
|
\f(CWll\fP 6
|
|
\f(CWls\fP 5
|
|
\f(CWlt\fP 14
|
|
\f(CWmc\fP 20
|
|
\f(CWmk\fP 3
|
|
\f(CWna\fP 4
|
|
\f(CWne\fP 3
|
|
\f(CWnf\fP 4
|
|
\f(CWnh\fP 13
|
|
\f(CWnm\fP 15
|
|
\f(CWnn\fP 15
|
|
\f(CWnr\fP 8
|
|
\f(CWns\fP 5
|
|
\f(CWnx\fP 19
|
|
\f(CWos\fP 5
|
|
\f(CWpc\fP 14
|
|
\f(CWpi\fP 19
|
|
\f(CWpl\fP 3
|
|
\f(CWpm\fP 20
|
|
\f(CWpn\fP 3
|
|
\f(CWpo\fP 3
|
|
\f(CWps\fP 2
|
|
\f(CWrd\fP 18
|
|
\f(CWrm\fP 7
|
|
\f(CWrn\fP 7
|
|
\f(CWrr\fP 8
|
|
\f(CWrs\fP 5
|
|
\f(CWrt\fP 3
|
|
\f(CWso\fP 19
|
|
\f(CWsp\fP 5
|
|
\f(CWss\fP 2
|
|
\f(CWsv\fP 5
|
|
\f(CWsy\fP 19
|
|
\f(CWta\fP 9
|
|
\f(CWtc\fP 9
|
|
\f(CWti\fP 6
|
|
\f(CWtl\fP 14
|
|
\f(CWtm\fP 20
|
|
\f(CWtr\fP 10
|
|
\f(CWuf\fP 10
|
|
\f(CWul\fP 10
|
|
\f(CWvs\fP 5
|
|
\f(CWwh\fP 7
|
|
.di
|
|
.nr aa \n(dn/\n(zz
|
|
.ne \\n(aau+10p
|
|
.sp
|
|
.SP 2
|
|
.TL
|
|
Alphabetical Request and Section Number Cross Reference
|
|
.SP .5
|
|
.LP
|
|
.sp .5
|
|
.nf
|
|
.wh \n(nlu+\n(aau cl
|
|
.nr qq \n(nlu+\n(aau
|
|
.ps
|
|
.vs
|
|
.mk
|
|
.zz
|
|
.rt
|
|
.sp \n(.tu
|
|
.ch cl 12i
|
|
.sp 100
|
|
.BP
|
|
.TL
|
|
Escape Sequences for Characters, Indicators, and Functions
|
|
.SP .5
|
|
.LP
|
|
.ps -1
|
|
.vs -1
|
|
.TS
|
|
center;
|
|
c2 l
|
|
c2 l2 l
|
|
n2 l2fCW l.
|
|
.ft 4
|
|
Section Escape
|
|
Reference Sequence Meaning
|
|
.ft
|
|
.sp .5
|
|
10.1 \e\e \&\f(CW\e\fP prevents or delays the interpretation of \&\f(CW\e\fP
|
|
10.1 \ee Printable version of the current escape character.
|
|
2.1 \e' \' (acute accent); equivalent to \&\f(CW\e(aa\fP
|
|
2.1 \e` \` (grave accent); equivalent to \&\f(CW\e(ga\fP
|
|
2.1 \e\- \- Minus sign in the current font
|
|
7. \e\^. Period (dot) (see \&\f(CWde\fP)
|
|
11.1 \e\f2space\fP Unpaddable space-size space character
|
|
11.1 \e0 Digit width space
|
|
11.1 \e| 1/6 em narrow space character (zero width in \*(NR\^)
|
|
11.1 \e^ 1/12 em half-narrow space character (zero width in \*(NR\^)
|
|
.tr &&
|
|
4.1 \e& Non-printing, zero width character
|
|
.tr &.
|
|
10.6 \e! Transparent line indicator
|
|
10.8 \e" Beginning of comment; continues to end of line
|
|
13. \e% Default optional hyphenation character
|
|
2.1 \e(@xx@ Character named @xx@
|
|
7.1 \e*@x,~@\e*(@xx@ Interpolate string @x@ or @xx@
|
|
7.3 \e$@N@ Interpolate argument @1 <= N <= 9@
|
|
9.1 \ea Non-interpreted leader character
|
|
12.3 \eb'@abc...@' Bracket building function
|
|
4.2 \ec Connect to next input text
|
|
2.1 \eC'@xyz@' Character named @xyz@
|
|
11.1 \ed Downward 1/2 em vertical motion (1/2 line in \*(NR\^)
|
|
12.5 \eD'@c...@' Draw graphics function @c@ with parameters @. . .@; @c= cw l , cw c , cw e , cw a , cw "~"@
|
|
2.2 \ef@x,~@\ef(@xx,~@\ef@N@ Change to font named @x@ or @xx@, or position @N@
|
|
8. \eg@x,~@\eg(@xx@ Format of number register @x@ or @xx@
|
|
11.1 \eh'@N@' Local horizontal motion; move right @N@ (negative left)
|
|
2.3 \eH'@N@' Height of current font is @N@
|
|
11.3 \ek@x@ Mark horizontal input place in register @x@
|
|
12.4 \el'@Nc@' Horizontal line drawing function (optionally with @c@ )
|
|
12.4 \eL'@Nc@' Vertical line drawing function (optionally with @c@ )
|
|
8. \en@x,~@\en(@xx@ Contents of number register @x@ or @xx@
|
|
2.1 \eN'@N@' Character number @N@ on current font
|
|
12.1 \eo'@abc...@' Overstrike characters @a,~ b,~ c@, ...
|
|
4.1 \ep Break and spread output line
|
|
11.1 \er Reverse 1 em vertical motion (reverse line in \*(NR\^)
|
|
2.3 \es@N,~@\es@+- N@ Point-size change function; also @cw "\es(" nn@, @cw "\es" +- cw "(" nn@
|
|
2.2 \eS'@N@' Slant output @N@ degrees
|
|
9.1 \et Non-interpreted horizontal tab
|
|
11.1 \eu Reverse (up) 1/2 em vertical motion (1/2 line in \*(NR\^)
|
|
11.1 \ev'@N@' Local vertical motion; move down N (negative up)
|
|
11.2 \ew'@string@' Width of @string@
|
|
5.2 \ex'@N@' Extra line-space function (negative before, positive after)
|
|
10.7 \eX'@string@' Output @string@ as device control function
|
|
12.2 \ez@c@ Print @c@ with zero width (without spacing)
|
|
16. \e{ Begin conditional input
|
|
16. \e} End conditional input
|
|
10.8 \e@newline@ Concealed (ignored) newline
|
|
- \e@Z@ @Z@, any character not listed above
|
|
.TE
|
|
.ps +1
|
|
.vs +1
|
|
.LP
|
|
The escape sequences
|
|
.CW \e\e ,
|
|
.CW \e\^. ,
|
|
.CW \e" ,
|
|
.CW \e$ ,
|
|
.CW \e* ,
|
|
.CW \ea ,
|
|
.CW \en ,
|
|
.CW \et ,
|
|
.CW \eg ,
|
|
and
|
|
.CW \e@newline@
|
|
are interpreted in copy mode (§7.2).
|
|
.SP .5i
|
|
\0
|
|
.sp 100
|
|
.BP
|
|
.TL
|
|
Predefined Number Registers
|
|
.LP
|
|
.ps -1
|
|
.vs -1
|
|
.TS
|
|
c2l
|
|
c2 l2 l
|
|
n2 l2fCW l.
|
|
.ft 4
|
|
Section Register
|
|
Reference Name Description
|
|
.ft
|
|
.sp .5
|
|
3. % Current page number.
|
|
11.2 ct Character type (set by \&\f(CW\ew\fP function).
|
|
7.4 dl Width (maximum) of last completed diversion.
|
|
7.4 dn Height (vertical size) of last completed diversion.
|
|
- dw Current day of the week (1-7).
|
|
- dy Current day of the month (1-31).
|
|
15. ln Output line number.
|
|
- mo Current month (1-12).
|
|
4.1 nl Vertical position of last printed text baseline.
|
|
11.2 sb Depth of string below baseline (generated by \&\f(CW\ew\fP function).
|
|
11.2 st Height of string above baseline (generated by \&\f(CW\ew\fP function).
|
|
- yr Last two digits of current year.
|
|
.TE
|
|
.ps +1
|
|
.vs +1
|
|
|
|
|
|
.TL
|
|
Predefined Read-Only Number Registers
|
|
.LP
|
|
.ps -1
|
|
.vs -1
|
|
.TS
|
|
c2 l
|
|
c2 l2 l
|
|
n2 l2fCW l.
|
|
.ft 4
|
|
Section Register
|
|
Reference Name Description
|
|
.ft
|
|
.sp .5
|
|
19. $$ Process id of \*(TR or \*(NR.
|
|
7.3 &$ Number of arguments available at the current macro level.
|
|
5.2 &a Post-line extra line-space most recently used in @cw "\ex'" N cw "'" @.
|
|
- &A Set to 1 in \*(TR, if @cw -a@ option used; always 1 in \*(NR.
|
|
2.3 &b Emboldening level.
|
|
20. &c Number of lines read from current input file.
|
|
7.4 &d Current vertical place in current diversion; equal to @cw nl@, if no diversion.
|
|
2.2 &f Current font number.
|
|
20. &F Current input file name [sic].
|
|
4. &h Text baseline high-water mark on current page or diversion.
|
|
11.1 &H Available horizontal resolution in basic units.
|
|
6. &i Current indent.
|
|
4.2 &j Current @cw ad@ mode.
|
|
4.1 &k Current output horizontal position.
|
|
6. &l Current line length.
|
|
5.1 &L Current @cw ls@ value.
|
|
4. &n Length of text portion on previous output line.
|
|
3. &o Current page offset.
|
|
3. &p Current page length.
|
|
7.5 .R Number of unused number registers.
|
|
- &T Set to 1 in \*(NR, if \&\f(CW-T\fP option used; always 0 in \*(TR.
|
|
2.3 &s Current point size.
|
|
7.5 &t Distance to the next trap.
|
|
4.1 &u Equal to 1 in fill mode and 0 in nofill mode.
|
|
5.1 &v Current vertical line spacing.
|
|
11.1 &V Available vertical resolution in basic units.
|
|
11.2 &w Width of previous character.
|
|
- &x Reserved version-dependent register.
|
|
- &y Reserved version-dependent register.
|
|
7.4 &z Name [sic] of current diversion.
|
|
.TE
|
|
.ps +1
|
|
.vs +1
|
|
.sp 100
|
|
.BP
|
|
.TL
|
|
Reference Manual
|
|
.NH
|
|
General Explanation
|
|
.sc "Form of input.
|
|
Input consists of \fItext lines\fR, which are destined to be printed,
|
|
interspersed with \fIcontrol lines\fR,
|
|
which set parameters or otherwise control subsequent processing.
|
|
Control lines begin with a \fIcontrol character\fR\(em\
|
|
normally \&\f(CW.\fR (period) or \&\f(CW'\fR (single quote)\(em\
|
|
followed by a one or two character name that specifies
|
|
a basic \fIrequest\fR or the substitution of
|
|
a user-defined \fImacro\fR in place of the control line.
|
|
The control character \&\f(CW'\fR suppresses the \fIbreak\fR function\(em\
|
|
the forced output of a partially filled line\(em\
|
|
caused by certain requests.
|
|
The control character may be separated from the request/macro name by
|
|
white space (spaces and/or tabs) for aesthetic reasons.
|
|
Names should be followed by either
|
|
space or newline.
|
|
Control lines with unrecognized names are ignored.
|
|
.PP
|
|
Various special functions may be introduced anywhere in the input by
|
|
means of an \fIescape\fR character, normally \&\f(CW\e\fR.
|
|
For example, the function
|
|
.CW \en@R@
|
|
causes the interpolation of the contents of the
|
|
\fInumber register R\fR
|
|
in place of the function;
|
|
here @R@ is either a single character name
|
|
as in \&\f(CW\en\fIx\fR,
|
|
or a two-character name introduced by
|
|
a left-parenthesis, as in \&\f(CW\en(\fIxx\fR.
|
|
.sc "Formatter and device resolution.
|
|
\*(Tr internally stores and processes dimensions in units that correspond to
|
|
the particular device for which output is being prepared;
|
|
values from 300 to 1200/inch are typical.
|
|
See §23.
|
|
\*(Nr internally uses 240 units/inch,
|
|
corresponding to the least common multiple of the
|
|
horizontal and vertical resolutions of various
|
|
typewriter-like output devices.
|
|
\*(Tr rounds horizontal/vertical numerical parameter input to the actual
|
|
horizontal/vertical resolution of the output device indicated by the \&\f(CW-T\fR option
|
|
(default
|
|
.CW post ).
|
|
\*(Nr similarly rounds numerical input to the actual resolution
|
|
of its output device
|
|
(default Model 37 Teletype).
|
|
.sc "Numerical parameter input.
|
|
Both \*(NR and \*(TR
|
|
accept numerical input with the appended scale
|
|
indicators
|
|
shown in the following table,
|
|
where
|
|
\fIS\fR is the current type size in points and
|
|
\fIV\fR is the current vertical line spacing in
|
|
basic units.
|
|
.TS
|
|
center box;
|
|
c|c
|
|
c|c
|
|
c|l.
|
|
Scale
|
|
Indicator Meaning
|
|
_
|
|
\&\f(CWi\fR Inch
|
|
\&\f(CWc\fR Centimeter
|
|
\&\f(CWP\fR Pica = 1/6 inch
|
|
\&\f(CWm\fR Em = \fIS\fR points
|
|
\&\f(CWn\fR En = Em/2
|
|
\&\f(CWp\fR Point = 1/72 inch
|
|
\&\f(CWu\fR Basic unit
|
|
\&\f(CWv\fR Vertical line space \fIV\fR
|
|
none Default, see below
|
|
.TE
|
|
In \*(NR, both the em and the en are taken to be equal to the
|
|
nominal character width,
|
|
which is output-device dependent;
|
|
common values are 1/10 and 1/12 inch.
|
|
Actual character widths in \*(NR need not be all the same and constructed characters
|
|
such as -> (→) are often extra wide.
|
|
The default scaling is
|
|
.CW m
|
|
for the horizontally-oriented requests
|
|
and functions
|
|
.CW ll ,
|
|
.CW in ,
|
|
.CW ti ,
|
|
.CW ta ,
|
|
.CW lt ,
|
|
.CW po ,
|
|
.CW mc ,
|
|
.CW \eh ,
|
|
.CW \el ,
|
|
and horizontal coordinates of
|
|
.CW \eD ;
|
|
.CW v
|
|
for the vertically-oriented requests and functions
|
|
.CW pl ,
|
|
.CW wh ,
|
|
.CW ch ,
|
|
.CW dt ,
|
|
.CW sp ,
|
|
.CW sv ,
|
|
.CW ne ,
|
|
.CW rt ,
|
|
.CW \ev ,
|
|
.CW \ex ,
|
|
.CW \eL ,
|
|
and vertical coordinates of
|
|
.CW \eD ;
|
|
.CW p
|
|
for the
|
|
.CW vs
|
|
request;
|
|
and
|
|
.CW u
|
|
for the requests
|
|
.CW nr ,
|
|
.CW if ,
|
|
and
|
|
.CW ie .
|
|
\fIAll\fR other requests ignore any scale indicators.
|
|
When a number register containing an already appropriately scaled number
|
|
is interpolated to provide numerical input,
|
|
the unit scale indicator
|
|
\&\f(CWu\fR may need to be appended to prevent
|
|
an additional inappropriate default scaling.
|
|
The number, @N@, may be specified in decimal-fraction form
|
|
but the parameter finally stored is rounded to an integer number of basic units.
|
|
Internal computations are performed in integer arithmetic.
|
|
.PP
|
|
The \fIabsolute position\fR indicator \&\f(CW|\fR may be prefixed
|
|
to a number @N@
|
|
to generate the distance to the vertical or horizontal place @N@.
|
|
For vertically-oriented requests and functions, \&\f(CW|\fP@N@
|
|
becomes the distance in basic units from the current vertical place on the page or in a \fIdiversion\fR (§7.4)
|
|
to the vertical place @N@.
|
|
For \fIall\fR other requests and functions,
|
|
\&\f(CW|\fP@N@
|
|
becomes the distance from
|
|
the current horizontal place on the \fIinput\fR line to the horizontal place @N@.
|
|
For example,
|
|
.P1
|
|
\&.sp |3.2c
|
|
.P2
|
|
will space in the required direction to 3.2 centimeters from the top of the page.
|
|
.sc "Numerical expressions.
|
|
.tr &&
|
|
Wherever numerical input is expected,
|
|
an expression involving parentheses,
|
|
the arithmetic operators \&\f(CW+\fR, \&\f(CW-\fR, \&\f(CW/\fR, \&\f(CW\(**\fR, \&\f(CW%\fR (mod),
|
|
and the logical operators
|
|
\&\f(CW<\fR,
|
|
\&\f(CW>\fR,
|
|
\&\f(CW<=\fR,
|
|
\&\f(CW>=\fR,
|
|
\&\f(CW=\fR (or \&\f(CW==\fR),
|
|
\&\f(CW&\fR\ (and),
|
|
\&\f(CW:\fR\ (or)
|
|
may be used.
|
|
Except where controlled by parentheses, evaluation of expressions is left-to-right;
|
|
there is no operator precedence.
|
|
In the case of certain requests, an initial \&\f(CW+\fR or \&\f(CW-\fR is stripped
|
|
and interpreted as an increment or decrement indicator respectively.
|
|
In the presence of default scaling, the desired scale indicator must be
|
|
attached to \fIevery\fR number in an expression
|
|
for which the desired and default scaling differ.
|
|
For example,
|
|
if the number register \&\f(CWx\fR contains 2
|
|
and the current point size is 10,
|
|
then
|
|
.P1
|
|
\&.ll (4.25i+\enxP+3)/2u
|
|
.P2
|
|
will set the line length to 1/2 the sum of 4.25 inches + 2 picas + 3 ems.
|
|
.sc "Notation.
|
|
Numerical parameters are indicated in this manual in two ways.
|
|
@+- N@ means that the argument may take the forms @N@, @+N@, or @-N@ and
|
|
that the corresponding effect is to set the parameter
|
|
to @N@, to increment it by @N@, or to decrement it by @N@ respectively.
|
|
Plain @N@ means that an initial algebraic sign is \fInot\fR
|
|
an increment indicator,
|
|
but merely the sign of @N@.
|
|
Generally, unreasonable numerical input is either ignored
|
|
or truncated to a reasonable value.
|
|
For example,
|
|
most requests expect to set parameters to non-negative
|
|
values;
|
|
exceptions are
|
|
.CW sp ,
|
|
.CW wh ,
|
|
.CW ch ,
|
|
.CW nr ,
|
|
and
|
|
.CW if .
|
|
The requests
|
|
.CW ps ,
|
|
.CW ft ,
|
|
.CW po ,
|
|
.CW vs ,
|
|
.CW ls ,
|
|
.CW ll ,
|
|
.CW in ,
|
|
and
|
|
.CW lt
|
|
restore the previous parameter value in the absence
|
|
of an argument.
|
|
.PP
|
|
Single character arguments are indicated by single lower case letters
|
|
and
|
|
one/two character arguments are indicated by a pair of lower case letters.
|
|
Character string arguments are indicated by multi-character mnemonics.
|
|
.NH
|
|
Font and Character Size Control
|
|
.sc "Character set.
|
|
The \*(TR character set is defined by a description file specific to each output device (§23).
|
|
There are normally several regular fonts and one or more special fonts.
|
|
Characters are input as themselves,
|
|
as @cw "\e(" xx@, as @cw "\eC'" name cw "'"@,
|
|
or as
|
|
.CW \eN'@n@' .
|
|
The form
|
|
.CW \eC'@name@'
|
|
permits a name of any length;
|
|
the form
|
|
.CW \eN'@n@'
|
|
refers to the @n@-th character on the current font,
|
|
whether named or not.
|
|
.PP
|
|
Normally the input characters
|
|
.CW ` ,
|
|
.CW ' ,
|
|
and
|
|
.CW -
|
|
are printed as `, ', and - respectively;
|
|
.CW \e` ,
|
|
.CW \e' ,
|
|
and
|
|
.CW \e-
|
|
produce \`, \', and \-.
|
|
If the character does not exist in the font, \*(TR assumes the width is 1 em and
|
|
outputs the character with a
|
|
.CW C
|
|
name as defined in Section 22.
|
|
(This is independent of how the device handles characters unknown to it.)
|
|
.PP
|
|
\*(Nr has an analogous, but different, mechanism for defining legal characters
|
|
and how to print them.
|
|
By default all characters are valid.
|
|
There are such
|
|
additional characters as may be available on
|
|
the output device,
|
|
such characters as may be constructed
|
|
by overstriking or other combination,
|
|
and those that can reasonably be mapped
|
|
into other printable characters.
|
|
The exact behavior is determined by a driving
|
|
table prepared for each device.
|
|
.sc "Fonts.
|
|
\*(Tr
|
|
begins execution by reading information for a set of defaults fonts,
|
|
said to be
|
|
.I mounted ;
|
|
conventionally, the first four are
|
|
Times Roman (\&\f(CWR\fR),
|
|
Times Italic
|
|
(\&\f(CWI\fR),
|
|
Times Bold
|
|
(\&\f(CWB\fR),
|
|
and
|
|
Times Bold Italic
|
|
(\&\f(CWBI\fR) ,
|
|
and the last is a Special font
|
|
.CW S ) (
|
|
containing miscellaneous characters.
|
|
(This document uses Lucida Sans in place of Times.)
|
|
The set of fonts and positions is determined by the device description file,
|
|
described in §23.
|
|
.PP
|
|
The current font, initially Roman, may be changed
|
|
by the \&\f(CWft\fR request,
|
|
or by embedding at any desired point
|
|
\&\f(CW\ef\fIx\fR, \&\f(CW\ef(\fIxx\fR, or \&\f(CW\ef\fP@N@,
|
|
where
|
|
\fIx\fR and \fIxx\fR are the name of a font
|
|
and @N@ is a numerical font position.
|
|
.PP
|
|
It is not necessary to change to the Special font;
|
|
characters on that font are automatically handled
|
|
as if they were physically part of the current font.
|
|
The Special font may actually be several fonts;
|
|
the name
|
|
.CW S
|
|
is reserved and is generally used for one of these.
|
|
All special fonts must be mounted after regular fonts.
|
|
.PP
|
|
\*(Tr can be informed that any particular font is mounted
|
|
by use of the \&\f(CWfp\fR request.
|
|
The list of known fonts is installation dependent.
|
|
In the subsequent discussion of font-related requests,
|
|
@F@ represents either a one/two-character
|
|
font name or the numerical font position.
|
|
The current font is available (as a numerical position) in the read-only number register \&\f(CW.f\fR.
|
|
.PP
|
|
A request for a named but not-mounted font is honored
|
|
if the font description information exists.
|
|
In this way, there is no limit on the number of fonts that may be printed
|
|
in any part of a document.
|
|
Mounted fonts may be handled more efficiently,
|
|
and they may be referred to by their mount positions,
|
|
but there is no other difference.
|
|
Mention of an unmounted font loads it temporarily at font position
|
|
zero, which serves as a one-font cache.
|
|
.PP
|
|
The function
|
|
.CW \eS'@+- N@'
|
|
causes the current font to be slanted by
|
|
@+- N@
|
|
degrees.
|
|
Not all devices support slanting.
|
|
.PP
|
|
\*(Nr understands font control
|
|
and normally underlines italic characters (see §10.5).
|
|
.sc "Character size.
|
|
Character point sizes available depend on the specific output device;
|
|
a typical (historical) set of values is
|
|
6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 28, and 36.
|
|
This is a range of 1/12 inch to 1/2 inch.
|
|
The \&\f(CWps\fR request is used to change or restore the point size.
|
|
Alternatively the point size may be changed between any two characters
|
|
by embedding a
|
|
.CW \es@N@
|
|
at the desired point
|
|
to set the size to @N@,
|
|
or a
|
|
.CW "\&\f(CW\es@+- N@
|
|
(@1 <= N <= 9@)
|
|
to increment/decrement the size by @N@;
|
|
.CW \es0
|
|
restores the previous size.
|
|
Requested point size values that are between two valid
|
|
sizes yield the larger of the two.
|
|
.PP
|
|
Note that through an accident of history, a construction like
|
|
.CW \es39
|
|
is parsed as size 39, and thus converted to size 36 (given the sizes above),
|
|
while
|
|
.CW \es40
|
|
is parsed as size 4 followed by
|
|
.CW 0 .
|
|
The forms
|
|
@cw "\es(" nn@ and @cw "\es" +- cw "(" nn@
|
|
permit specification of sizes that would otherwise be ambiguous.
|
|
.PP
|
|
The current size is available in the \&\f(CW.s\fR register.
|
|
\*(Nr ignores type size requests.
|
|
.PP
|
|
The function
|
|
.CW "\eH'@+- N@'
|
|
sets \H'+2'the height of the current font\H'0' to
|
|
@N@, or increments it by @+N@, or decrements it by @-N@;
|
|
if @N=0@, the height is restored to the current point size.
|
|
In each case, the width is unchanged.
|
|
Not all devices support independent height and width for characters.
|
|
.FS
|
|
*The fields have the same meaning as described earlier in the Request Summary.
|
|
.FE
|
|
.SP .5
|
|
.LP
|
|
.ne 2.1
|
|
.ta 1.5i 2.5i 3.5i 4.5i
|
|
\f2Request\fR \f2Initial\fR \f2If\ No\fR
|
|
.br
|
|
\f2Form\fR \f2Value\fR \f2Argument\fR \f2Notes\fR
|
|
.bt "\&\f(CW.ps\fI \(+-N\fR*" "10\|point" "previous" "E" "Point size
|
|
set to @+- N@.
|
|
Alternatively, embed
|
|
.CW \es@N@
|
|
or
|
|
.CW "\&\f(CW\es@+- N@" .
|
|
Any positive size value may be requested;
|
|
if invalid, the next larger valid size will result, with a
|
|
maximum of 36.
|
|
A paired sequence
|
|
@+N@, @-N@
|
|
will work because the previous requested value is also remembered.
|
|
Ignored in \*(NR.
|
|
.bt "\&\f(CW.ss\fI N\fR" "12/36\|em" "ignored" "E" "Space-character size
|
|
(i.e., inter-word gap)
|
|
is set to @N@/36 ems.
|
|
This size is the minimum word spacing in adjusted text.
|
|
Ignored in \*(NR.
|
|
.bt "\&\f(CW.cs\fI\|F\|N\|M\fR" "off" "-" "P" "Constant character space
|
|
(width) mode is
|
|
set on for font @F@ (if mounted); the width of every character will be
|
|
taken to be @N@/36 ems.
|
|
If @M@ is absent,
|
|
the em is that of the character's point size;
|
|
if @M@ is given,
|
|
the em is @M@ points.
|
|
All affected characters
|
|
are centered in this space, including those with an actual width
|
|
larger than this space.
|
|
Special Font characters occurring while the current font
|
|
is @F@ are also so treated.
|
|
If @N@ is absent, the mode is turned off.
|
|
The mode must be in effect when the characters are physically printed.
|
|
Ignored in \*(NR.
|
|
.bt "\&\f(CW.bd\fI F N\fR" "off" "-" "P" "The characters in font @F@ will be artificially
|
|
emboldened by printing each one twice, separated by @N-1@ basic units.
|
|
A reasonable value for @N@ is 3 when the character size is near 10 points.
|
|
If @N@ is missing the embolden mode is turned off.
|
|
The emboldening value @N@ is in the \&\f(CW.b\fP register.
|
|
.IP
|
|
.bd R 3
|
|
This paragraph is printed with \&\f(CW.bd R 3\fR.
|
|
The mode must be in effect when the characters are physically printed.
|
|
Ignored in \*(NR.
|
|
.br
|
|
.bd R
|
|
.bt "\&\f(CW.bd S \fIF N\fR" "off" "-" "P" "The characters in the Special font
|
|
will be emboldened whenever the current font is @F@.
|
|
The mode must be in effect when the characters are physically printed.
|
|
Ignored in \*(NR.
|
|
.bt "\&\f(CW.ft\fP @F@" "Roman" "previous" "E" "Font changed to
|
|
@F@.
|
|
Alternatively, embed
|
|
.CW \ef@F@ .
|
|
The font name \&\f(CWP\fR is reserved to mean the previous font,
|
|
and the name
|
|
.CW S
|
|
for the special font.
|
|
.bt "\&\f(CW.fp \fIN F L\fR" "R,I,B,...,S" "ignored" "-" "Font position.
|
|
This is a statement
|
|
that a font named @F@ is associated with position @N@.
|
|
It is a fatal error if @F@ is not known.
|
|
For fonts with names longer than two characters,
|
|
.I L
|
|
refers to the long name,
|
|
and
|
|
.I F
|
|
becomes a synonym.
|
|
There is generally a limit of about 10 mounted fonts.
|
|
.NH
|
|
Page control
|
|
.PP
|
|
Top and bottom margins are not automatically provided;
|
|
it is conventional to define two \fImacros\fR and to set \fItraps\fR
|
|
for them at vertical positions 0 (top) and @-N@ (distance @N@ up from the bottom).
|
|
See §7 and Tutorial Examples §T2.
|
|
A pseudo-page transition onto the first page occurs
|
|
either when the first \fIbreak\fR occurs or
|
|
when the first \fInon-diverted\fR text processing occurs.
|
|
Arrangements
|
|
for a trap to occur at the top of the first page
|
|
must be completed before this transition.
|
|
In the following, references to the \fIcurrent diversion\fR (§7.4)
|
|
mean that the mechanism being described works during both
|
|
ordinary and diverted output (the former considered as the top diversion level).
|
|
.PP
|
|
The limitations on \*(TR and \*(NR output dimensions
|
|
are device dependent.
|
|
.bt "\&\f(CW.pl\fI \(+-N\fR" "11\|in" "11\|in" "\fBv\fR" "Page length set to @+- N@.
|
|
The current page length is available in the \&\f(CW.p\fR register.
|
|
.bt "\&\f(CW.bp\fI \(+-N\fR" "\fIN\(eq\fR1" "-" "B,\fBv\fR" "Begin page.
|
|
The current page is ejected and a new page is begun.
|
|
If @+- N@ is given, the new page number will be @+- N@.
|
|
Also see request \&\f(CWns\fR.
|
|
.bt "\&\f(CW.pn\fI \(+-N\fR" "@N@\(eq1" "ignored" "-" "Page number.
|
|
The next page (when it occurs) will have the page number @+- N@.
|
|
A \&\f(CWpn\fR must occur before the initial pseudo-page transition
|
|
to affect the page number of the first page.
|
|
The current page number is in the \&\f(CW%\fR register.
|
|
.bt "\&\f(CW.po\fI \(+-N\fR" "1\|in; 0" "previous" "\fBv\fR" "Page offset.
|
|
The current \fIleft margin\fR is set to @+- N@.
|
|
The \*(TR initial value provides 1 inch of paper margin
|
|
on a typical device.
|
|
The current page offset is available in the \&\f(CW.o\fR register.
|
|
.bt "\&\f(CW.ne\fI N\fR" "-" "\fIN\(eq\fR1\|\fIV\fR" "D,\fBv\fR" "Need @N@ vertical space.
|
|
If the distance \fID\fR to the next trap position (see §7.5) is less than @N@,
|
|
a forward vertical space of size \fID\fR occurs,
|
|
which will spring the trap.
|
|
If there are no remaining
|
|
traps on the page,
|
|
\fID\fR is the distance to the bottom of the page.
|
|
If @D<V@, another line could still be output
|
|
and spring the trap.
|
|
In a diversion, \fID\fR is the distance to the \fIdiversion trap\fR, if any,
|
|
or is very large.
|
|
.bt "\&\f(CW.mk\fI R\fR" "none" "internal" "D" "Mark the current vertical place
|
|
in an internal register (both associated with the current diversion level),
|
|
or in register @R@, if given.
|
|
See \&\f(CWrt\fR request.
|
|
.bt "\&\f(CW.rt\fI \(+-N\fR" "none" "internal" "D,\fBv\fR" "Return \fIupward only\fR to a marked vertical place
|
|
in the current diversion.
|
|
If @+- N@ (with respect to current place) is given,
|
|
the place is @+- N@ from the top of the page or diversion
|
|
or, if @N@ is absent, to a
|
|
place marked by a previous \&\f(CWmk\fR.
|
|
The \&\f(CWsp\fR request (§5.3) may be used
|
|
instead of \&\f(CWrt\fR
|
|
by spacing to the absolute place stored in a explicit register,
|
|
e.g., using
|
|
.CW ".mk
|
|
@R@ ...\&
|
|
.CW ".sp
|
|
.CW |\en@R@u ;
|
|
this also works when the motion is downwards.
|
|
.NH
|
|
Text Filling, Adjusting, and Centering
|
|
.sc "Filling and adjusting.
|
|
Normally,
|
|
words are collected from input text lines
|
|
and assembled into a output text line
|
|
until some word does not fit.
|
|
An attempt is then made
|
|
to hyphenate the word to put part
|
|
of it into the output line.
|
|
The spaces between the words on the output line
|
|
are then increased to spread out the line
|
|
to the current \fIline length\fR
|
|
minus any current \fIindent\fR.
|
|
A \fIword\fR is any string of characters delimited by
|
|
the \fIspace\fR character or the beginning/end of the input line.
|
|
Any adjacent pair of words that must be kept together
|
|
(neither split across output lines nor spread apart
|
|
in the adjustment process)
|
|
can be tied together by separating them with the
|
|
\fIunpaddable space\fR character
|
|
``\&\f(CW\e\ \fR'' (backslash-space).
|
|
The adjusted word spacings are uniform in \*(TR
|
|
and the minimum interword spacing can be controlled
|
|
with the \&\f(CWss\fR request (§2).
|
|
In \*(NR, they are normally nonuniform because of
|
|
quantization to character-size spaces;
|
|
however,
|
|
the command line option \&\f(CW-e\fR causes uniform
|
|
spacing with full output device resolution.
|
|
Filling, adjustment, and hyphenation (§13) can all be
|
|
prevented or controlled.
|
|
The text length on the last line output is available in the \&\f(CW.n\fR register,
|
|
and text baseline position on the page for this line is in the \&\f(CWnl\fR register.
|
|
The text baseline high-water mark (lowest place) on the current page is in
|
|
the \&\f(CW.h\fR register.
|
|
The current horizontal output position is in the \&\f(CW.k\fP register.
|
|
.PP
|
|
An input text line
|
|
.I ending
|
|
with \&\f(CW.\fR\^, \&\f(CW?\fR, or \&\f(CW!\fR,
|
|
optionally followed by any number of
|
|
.CW \&" ,
|
|
.CW ' ,
|
|
.CW ) ,
|
|
.CW ] ,
|
|
.CW * ,
|
|
or
|
|
†,
|
|
is taken
|
|
to be the end of a sentence, and an additional space character is
|
|
automatically provided during filling.
|
|
To prevent this, add
|
|
.CW \e&
|
|
to the end of the input line.
|
|
Multiple inter-word space characters found in the input are retained,
|
|
except for trailing spaces;
|
|
initial spaces also cause a break.
|
|
.PP
|
|
When filling is in effect, a \&\f(CW\ep\fR may be embedded or attached to a word to
|
|
cause a break at the end of the word and have the resulting output
|
|
line spread out to fill the current line length.
|
|
.PP
|
|
.tr &&
|
|
A text input line that happens to begin
|
|
with a control character can
|
|
be made not to look like a control line
|
|
by prefixing it with
|
|
the non-printing, zero-width filler character \&\f(CW\e&\fR.
|
|
Still another way is to specify output translation of some
|
|
convenient character into the control character
|
|
using \&\f(CWtr\fR (§10.5).
|
|
.tr &.
|
|
.sc "Interrupted text.
|
|
The copying of a input line in \fInofill\f (non-fill) mode can be interrupted
|
|
by terminating
|
|
the partial line with a \&\f(CW\ec\fR.
|
|
The next encountered input text line will be considered to be a continuation
|
|
of the same line of input text.
|
|
Similarly,
|
|
a word within \fIfilled\fR text may be interrupted by terminating the
|
|
word (and line) with \&\f(CW\ec\fR;
|
|
the next encountered text will be taken as a continuation of the
|
|
interrupted word.
|
|
If the intervening control lines cause a break,
|
|
any partial line will be forced out along with any partial word.
|
|
.bt "\&\f(CW.br\fR" "-" "-" "B" "Break.
|
|
The filling of the line currently
|
|
being collected is stopped and
|
|
the line is output without adjustment.
|
|
Text lines beginning with space characters
|
|
(but not tabs)
|
|
and empty text lines (blank lines) also cause a break.
|
|
.bt "\&\f(CW.fi\fR" "fill on" - B,E "Fill subsequent output lines.
|
|
The register \&\f(CW.u\fR is 1 in fill mode and 0 in nofill mode.
|
|
.bt "\&\f(CW.nf\fR" "fill on" "-" "B,E" "Nofill.
|
|
Subsequent output lines are neither filled nor adjusted.
|
|
Input text lines are copied directly to output lines
|
|
without regard for the current line length.
|
|
.bt "\&\f(CW.ad\fI c\fR" "adj, both" "adjust" "E" "Line adjustment is begun.
|
|
If fill mode is not on, adjustment will be deferred until
|
|
fill mode is back on.
|
|
If the type indicator @c@ is present,
|
|
the adjustment type is changed as shown in the following table.
|
|
.TS
|
|
center box;
|
|
c|c
|
|
c|l.
|
|
Indicator Adjust Type
|
|
_
|
|
\&\f(CWl\fR adjust left margin only
|
|
\&\f(CWr\fR adjust right margin only
|
|
\&\f(CWc\fR center
|
|
\&\f(CWb\fR or \&\f(CWn\fR adjust both margins
|
|
absent unchanged
|
|
.TE
|
|
The number register
|
|
.CW .j
|
|
contains the current value of the
|
|
.CW ad
|
|
setting;
|
|
its value can be recorded and used subsequently to set adjustment.
|
|
.bt "\&\f(CW.na\fR" "adjust" "-" "E" "Noadjust.
|
|
Adjustment is turned off;
|
|
the right margin will be ragged.
|
|
The adjustment type for \&\f(CWad\fR is not changed.
|
|
Output line filling still occurs if fill mode is on.
|
|
.bt "\&\f(CW.ce\fI N\fR" "off" "@N=1@" "B,E" "Center the next @N@ input text lines
|
|
within the current available horizontal space (line-length minus indent).
|
|
If @N=0@, any residual count is cleared.
|
|
A break occurs after each of the @N@ input lines.
|
|
If the input line is too long,
|
|
it will be left adjusted.
|
|
.NH
|
|
Vertical Spacing
|
|
.sc "Baseline spacing.
|
|
The vertical spacing @(V)@ between the baselines of successive
|
|
output lines can be set
|
|
using the \&\f(CWvs\fR request.
|
|
\fIV\fR should be large enough to accommodate the character sizes
|
|
on the affected output lines.
|
|
For the common type sizes (9-12 points),
|
|
usual typesetting practice is to set \fIV\fR to 2 points greater than the
|
|
point size;
|
|
\*(TR default is 10-point type on a 12-point spacing
|
|
(as in this document).
|
|
The current \fIV\fR is available in the \&\f(CW.v\fR register.
|
|
Multiple-\fIV\|\fR line separation (e.g., double spacing) may be requested
|
|
with \&\f(CWls\fR,
|
|
but it is better to use a large
|
|
.CW vs
|
|
instead;
|
|
certain preprocessors assume single spacing.
|
|
The current line spacing is available in the \&\f(CW.L\fP register.
|
|
.sc "Extra line-space.
|
|
If a word contains a tall construct requiring
|
|
the output line containing it to have extra vertical space
|
|
before and/or after it,
|
|
the \fIextra-line-space\fR function \&\f(CW\ex'\fIN\fP'\fR
|
|
can be embedded in or attached to that word.
|
|
If @N@ is negative,
|
|
the output line containing the word will
|
|
be preceded by @N@ extra vertical space;
|
|
if @N@ is positive,
|
|
the output line containing the word
|
|
will be followed by @N@ extra vertical space.
|
|
If successive requests for extra space apply to the same line,
|
|
the maximum values are used.
|
|
The most recently utilized post-line extra line-space is available in the \&\f(CW.a\fR register.
|
|
.PP
|
|
In
|
|
.CW \ex'\f2...\fP'
|
|
and other functions having a pair of delimiters around
|
|
their parameter,
|
|
the delimiter choice (here
|
|
.CW ' )
|
|
is arbitrary,
|
|
except that it can not look like the continuation of a number expression for @N@.
|
|
.sc "Blocks of vertical space.
|
|
A block of vertical space is ordinarily requested using \&\f(CWsp\fR,
|
|
which honors the \fIno-space\fR mode and which does
|
|
not space past a trap.
|
|
A contiguous block of vertical space may be reserved using \&\f(CWsv\fR.
|
|
.bt "\&\f(CW.vs \fIN\fR" "12pts; 1/6in" "previous" "E,\fBp\fR" "Set vertical baseline spacing size \fIV\fR.
|
|
Transient extra vertical space is available with \&\f(CW\ex\fI'N\|'\fR (see above).
|
|
.bt "\&\f(CW.ls \fIN\fR" "@N=1@" "previous" "E" "\fILine\fR spacing
|
|
set to @+- N@.
|
|
@N-1@ \fIV\fR\^s (blank lines) are
|
|
appended to each output text line.
|
|
Appended blank lines are omitted, if the text or previous appended blank line reached a trap position.
|
|
.bt "\&\f(CW.sp \fIN\fR" "-" "@N=1~V@" "B,\fBv\fR" "Space vertically in either direction.
|
|
If @N@ is negative, the motion is backward (upward)
|
|
and is limited to the distance to the top of the page.
|
|
Forward (downward) motion is truncated to the distance to the
|
|
nearest trap.
|
|
(Recall the use of
|
|
.CW ".sp |\f2N\fP
|
|
from §1.3.)
|
|
If the no-space mode is on,
|
|
no spacing occurs (see \&\f(CWns\fR and \&\f(CWrs\fR below).
|
|
.bt "\&\f(CW.sv\fI N\fR" "-" "@N=1~V@" "\fBv\fR" "Save a contiguous vertical block of size @N@.
|
|
If the distance to the next trap is greater
|
|
than @N@, @N@ vertical space is output.
|
|
No-space mode has no effect.
|
|
If this distance is less than @N@,
|
|
no vertical space is immediately output,
|
|
but @N@ is remembered for later output (see \&\f(CWos\fR).
|
|
Subsequent \&\f(CWsv\fR requests will overwrite any still remembered @N@.
|
|
.bt "\&\f(CW.os\fR" "-" "-" "-" "Output saved vertical space.
|
|
No-space mode has no effect.
|
|
Used to finally output a block of vertical space requested
|
|
by an earlier \&\f(CWsv\fR request.
|
|
.bt "\&\f(CW.ns\fR" "space" "-" "D" "No-space mode turned on.
|
|
When on, no-space mode inhibits \&\f(CWsp\fR requests and
|
|
\&\f(CWbp\fR requests \fIwithout\fR a next page number.
|
|
No-space mode is turned off when a line of
|
|
output occurs, or with \&\f(CWrs\fR.
|
|
.bt "\&\f(CW.rs\fR" "space" "-" "D" "Restore spacing.
|
|
The no-space mode is turned off.
|
|
.bt "\&Blank text line." "" "-" "B" "Causes a break and
|
|
output of a blank line exactly like \&\f(CWsp 1\fR.
|
|
.NH
|
|
Line Length and Indenting
|
|
.PP
|
|
The maximum line length for fill mode may be set with \&\f(CWll\fR.
|
|
The indent may be set with \&\f(CWin\fR;
|
|
an indent applicable to only the next output line may be set with \&\f(CWti\fR.
|
|
The line length includes indent space but not
|
|
page offset space.
|
|
The line length minus the indent is the basis for centering with \&\f(CWce\fR.
|
|
The effect of \&\f(CWll\fR, \&\f(CWin\fR, or \&\f(CWti\fR
|
|
is delayed, if a partially collected line exists,
|
|
until after that line is output.
|
|
In fill mode the length of text on an output line is less than or equal to
|
|
the line length minus the indent.
|
|
The current line length and indent are available in registers \&\f(CW.l\fR and \&\f(CW.i\fR respectively.
|
|
The length of \fIthree-part titles\fR produced by \&\f(CWtl\fR
|
|
(see §14) is independently set by \&\f(CWlt\fR.
|
|
.bt "\&\f(CW.ll\fI \(+-N\fR" "6.5\|in" "previous" "E,\fBm\fR" "Line length is set to \(+-@N@.
|
|
.bt "\&\f(CW.in\fI \(+-N\fR" "\fIN\(eq\^\fR0" "previous" "B,E,\fBm\fR" "Indent is set to @+- N@.
|
|
The indent is prefixed to each output line.
|
|
.bt "\&\f(CW.ti\fI \(+-N\fR" "-" "ignored" "B,E,\fBm\fR" "Temporary indent.
|
|
The next output text line will be indented a distance @+- N@
|
|
with respect to the current indent.
|
|
The resulting total indent may not be negative.
|
|
The current indent is not changed.
|
|
.NH
|
|
Macros, Strings, Diversion, and Position Traps
|
|
.sc "Macros and strings.
|
|
A \fImacro\fR is a named set of arbitrary \fIlines\fR that may be invoked by name or
|
|
with a \fItrap\fR.
|
|
A \fIstring\fR is a named string of \fIcharacters\fR,
|
|
not including a newline character,
|
|
that may be interpolated by name at any point.
|
|
Request, macro, and string names share the same name list.
|
|
Macro and string names
|
|
may be one or two characters long and may usurp previously defined
|
|
request, macro, or string names;
|
|
this implies that built-in operations may be (irrevocably) redefined.
|
|
Any of these entities may be renamed with \&\f(CWrn\fR
|
|
or removed with \&\f(CWrm\fR.
|
|
.PP
|
|
Macros are created by \&\f(CWde\fR and \&\f(CWdi\fR, and appended to by \&\f(CWam\fR and \&\f(CWda\fR;
|
|
\&\f(CWdi\fR and \&\f(CWda\fR cause normal output to be stored in a macro.
|
|
A macro is invoked in the same way as a request;
|
|
a control line beginning \&\f(CW.\fIxx\fR will interpolate the contents of macro \fIxx\fR.
|
|
The remainder of the line may contain up to nine \fIarguments\fR.
|
|
.PP
|
|
Strings are created by \&\f(CWds\fR and appended to by \&\f(CWas\fR.
|
|
The strings \fIx\fR and \fIxx\fR are interpolated at any desired point with
|
|
\&\f(CW\e\(**\fIx\fR and \&\f(CW\e\(**(\fIxx\fR respectively.
|
|
String references and macro invocations may be nested.
|
|
.sc "Copy mode input interpretation.
|
|
During the definition and extension
|
|
of strings and macros (not by diversion)
|
|
the input is read in \fIcopy mode\fR.
|
|
In copy mode, input is copied without interpretation
|
|
except that:
|
|
.IP
|
|
.ds + \v'-.1m'\s-4\(bu\s+4\v'+.1m'
|
|
.nf
|
|
\*+ The contents of number registers indicated by \&\f(CW\en\fR are interpolated.
|
|
\*+ Strings indicated by \&\f(CW\e\(**\fR are interpolated.
|
|
\*+ Arguments indicated by \&\f(CW\e$\fR are interpolated.
|
|
\*+ Concealed newlines indicated by \&\f(CW\e\fP\f2newline\fP are eliminated.
|
|
\*+ Comments indicated by \&\f(CW\e"\fR are eliminated.
|
|
\*+ \&\f(CW\et\fR and \&\f(CW\ea\fR are interpreted as \s-1ASCII\s+1 horizontal tab and \s-1SOH\s+1 respectively (§9).
|
|
\*+ \&\f(CW\e\e\fR is interpreted as \&\f(CW\e\fR.
|
|
\*+ \&\f(CW\e.\fR is interpreted as ``\&\f(CW.\fR''.
|
|
.LP
|
|
These interpretations can be suppressed by
|
|
prefixing
|
|
a \&\f(CW\e\fR.
|
|
For example, since \&\f(CW\e\e\fR maps into a \&\f(CW\e\fR, \&\f(CW\e\en\fR will copy as \&\f(CW\en\fR, which
|
|
will be interpreted as a number register indicator when the
|
|
macro or string is reread.
|
|
.sc "Arguments.
|
|
When a macro is invoked by name, the remainder of the line is
|
|
taken to contain up to nine arguments.
|
|
The argument separator is the space character (not tab), and arguments
|
|
may be surrounded by double quotes to permit embedded space characters.
|
|
Pairs of double quotes may be embedded in double-quoted arguments to
|
|
represent a single double-quote character.
|
|
The argument
|
|
.CW \&""
|
|
is explicitly null.
|
|
If the desired arguments won't fit on a line,
|
|
a concealed newline may be used to continue on the next line.
|
|
A trailing double quote may be omitted.
|
|
.PP
|
|
When a macro is invoked the \fIinput level\fR is \fIpushed down\fR and
|
|
any arguments available at the previous level become unavailable
|
|
until the macro is completely read and the previous level is restored.
|
|
A macro's own arguments can be interpolated at any point
|
|
within the macro with
|
|
.CW \e$@N@ ,
|
|
which interpolates the @N@\^th
|
|
argument
|
|
(@1 <= N <= 9@).
|
|
If an invoked argument does not exist,
|
|
a null string results.
|
|
For example, the macro \fIxx\fR may be defined by
|
|
.P1
|
|
.ta .75i
|
|
&de xx \e" begin definition
|
|
Today is \e\e$1 the \e\e$2.
|
|
&. \e" end definition
|
|
.P2
|
|
and called by
|
|
.P1
|
|
&xx Monday 14th
|
|
.P2
|
|
to produce the text
|
|
.P1
|
|
Today is Monday the 14th.
|
|
.P2
|
|
Note that each \&\f(CW\e$\fR
|
|
was concealed in the definition with a prefixed \&\f(CW\e\fR.
|
|
The number of
|
|
arguments is in the \&\f(CW.$\fR register.
|
|
.PP
|
|
No arguments are available at the top (non-macro) level,
|
|
within a string, or within a trap-invoked macro.
|
|
.PP
|
|
Arguments are copied in copy mode onto a stack
|
|
where they are available for reference.
|
|
It is advisable to
|
|
conceal string references (with an extra \&\f(CW\e\fR\|)
|
|
to delay interpolation until argument reference time.
|
|
.sc "Diversions.
|
|
Processed output may be diverted into a macro for purposes
|
|
such as footnote processing (see Tutorial §T5)
|
|
or determining the horizontal and vertical size of some text for
|
|
conditional changing of pages or columns.
|
|
A single diversion trap may be set at a specified vertical position.
|
|
The number registers \&\f(CWdn\fR and \&\f(CWdl\fR respectively contain the
|
|
vertical and horizontal size of the most
|
|
recently ended diversion.
|
|
Processed text that is diverted into a macro
|
|
retains the vertical size of each of its lines when reread
|
|
in \fInofill\fR mode
|
|
regardless of the current \fIV\fR.
|
|
Constant-spaced (\&\f(CWcs\fR) or emboldened (\&\f(CWbd\fR) text that is diverted
|
|
can be reread correctly only if these modes are again or still in effect
|
|
at reread time.
|
|
One way to do this is to embed in the diversion the appropriate
|
|
\&\f(CWcs\fR or \&\f(CWbd\fR requests with the \fItransparent\fR
|
|
mechanism described in §10.6.
|
|
.PP
|
|
Diversions may be nested
|
|
and certain parameters and registers
|
|
are associated
|
|
with the current diversion level
|
|
(the top non-diversion level may be thought of as the
|
|
0th diversion level).
|
|
These are the diversion trap and associated macro,
|
|
no-space mode,
|
|
the internally-saved marked place (see \&\f(CWmk\fR and \&\f(CWrt\fR),
|
|
the current vertical place (\&\f(CW.d\fR register),
|
|
the current high-water text baseline (\&\f(CW.h\fR register),
|
|
and the current diversion name (\&\f(CW.z\fR register).
|
|
.sc "Traps.
|
|
Three types of trap mechanisms are available\(empage traps, a diversion trap, and
|
|
an input-line-count trap.
|
|
Macro-invocation traps may be planted using \&\f(CWwh\fR at any page position including the top.
|
|
This trap position may be changed using \&\f(CWch\fR.
|
|
Trap positions at or below the bottom of the page
|
|
have no effect unless or until
|
|
moved to within the page or rendered effective by an increase in page length.
|
|
Two traps may be planted at the same position only by first planting them at different
|
|
positions and then moving one of the traps;
|
|
the first planted trap will conceal the second unless and until the first one is moved
|
|
(see Tutorial Examples).
|
|
If the first one is moved back, it again conceals the second trap.
|
|
The macro associated with a page trap is automatically
|
|
invoked when a line of text is output whose vertical size reaches
|
|
or sweeps past the trap position.
|
|
Reaching the bottom of a page springs the top-of-page trap, if any,
|
|
provided there is a next page.
|
|
The distance to the next trap position is available in the \&\f(CW.t\fR register;
|
|
if there are no traps between the current position and the bottom of the page,
|
|
the distance returned is the distance to the page bottom.
|
|
.PP
|
|
A macro-invocation trap effective in the current diversion may be planted using \&\f(CWdt\fR.
|
|
The \&\f(CW.t\fR register works in a diversion; if there is no subsequent trap a large
|
|
distance is returned.
|
|
For a description of input-line-count traps, see \&\f(CWit\fR below.
|
|
.bt "\&\f(CW&de\fI xx yy\fR" "-" "\fI.yy=\&\f(CW..\fR" "-" "Define or redefine the macro \fIxx\fR.
|
|
The contents of the macro begin on the next input line.
|
|
Input lines are copied in \fIcopy mode\fR until the definition is terminated by a
|
|
line beginning with \&\f(CW.\fIyy\fR,
|
|
whereupon the macro \fIyy\fR is called.
|
|
In the absence of \fIyy\fR, the definition
|
|
is terminated by a
|
|
line beginning with ``\&\f(CW..\fR''.
|
|
A macro may contain \&\f(CWde\fR requests
|
|
provided the terminating macros differ
|
|
or the contained definition terminator is concealed.
|
|
\&``\&\f(CW..\fR'' can be concealed as
|
|
\&\f(CW\e\e..\fR which will copy as \&\f(CW\e..\fR and be reread as ``\&\f(CW..\fR''.
|
|
.bt "\&\f(CW&am\fI xx yy\fR" "-" "\fI.yy=\&\f(CW..\fR" "-" "Append to macro
|
|
.I xx
|
|
(append version of \&\f(CWde\fR).
|
|
.bt "\&\f(CW&ds\fI xx string\fR" "-" "ignored" "-" "Define a string
|
|
\fIxx\fR containing \fIstring\fR.
|
|
Any initial double quote in \fIstring\fR is stripped off to permit
|
|
initial blanks.
|
|
.bt "\&\f(CW&as\fI xx string\fR" "-" "ignored" "-" "Append
|
|
\fIstring\fR to string \fIxx\fR
|
|
(append version of \&\f(CWds\fR).
|
|
.bt "\&\f(CW&rm\fI xx\fR" "-" "ignored" "-" "Remove
|
|
request, macro, or string.
|
|
The name \fIxx\fR is removed from the name list and
|
|
any related storage space is freed.
|
|
Subsequent references will have no effect.
|
|
If many macros and strings are being created dynamically, it
|
|
may become necessary to remove unused ones
|
|
to recapture internal storage space for newer registers.
|
|
.bt "\&\f(CW&rn\fI xx yy\fR" "-" "ignored" "-" "Rename request, macro, or string
|
|
\fIxx\fR to \fIyy\fR.
|
|
If \fIyy\fR exists, it is first removed.
|
|
.bt "\&\f(CW&di\fI xx\fR" "-" "end" "D" "Divert output to macro \fIxx\fR.
|
|
Normal text processing occurs during diversion
|
|
except that page offsetting is not done.
|
|
The diversion ends when the request \&\f(CWdi\fR or \&\f(CWda\fR is encountered without an argument;
|
|
extraneous
|
|
requests of this type should not appear when nested diversions are being used.
|
|
.bt "\&\f(CW&da \fIxx\fR" "-" "end" "D" "Divert, appending to macro \fIxx\fR
|
|
(append version of \&\f(CWdi\fR).
|
|
.bt "\&\f(CW&wh\fI N xx\fR" "-" "-" "\fBv\fR" "Install
|
|
a trap to invoke \fIxx\fR at page position \fIN\fR;
|
|
a negative N will be interpreted as a distance from the
|
|
page bottom.
|
|
Any macro previously planted at @N@ is replaced by \fIxx\fR.
|
|
A zero @N@ refers to the top of a page.
|
|
In the absence of \fIxx\fR, the first trap found at @N@, if any, is removed.
|
|
.bt "\&\f(CW&ch\fI xx N\fR" "-" "-" "\fBv\fR" "Change
|
|
the trap position for macro \fIxx\fR to be @N@.
|
|
In the absence of @N@, the trap, if any, is removed.
|
|
.bt "\&\f(CW&dt\fI N xx\fR" "-" "off" "D,\fBv\fR" "Install a diversion trap
|
|
at position @N@ in the \fIcurrent\fR diversion to invoke
|
|
macro \fIxx\fR.
|
|
Another \&\f(CWdt\fR will redefine the diversion trap.
|
|
If no arguments are given, the diversion trap is removed.
|
|
.bt "\&\f(CW&it\fI N xx\fR" "-" "off" "E" "Set an input-line-count trap
|
|
to invoke the macro \fIxx\fR after @N@ lines of \fItext\fR input
|
|
have been read
|
|
(control or request lines do not count).
|
|
The text may be inline text or
|
|
text interpolated by inline or trap-invoked macros.
|
|
.bt "\&\f(CW&em\fI xx\fR" "none" "none" "-" "The
|
|
macro \fIxx\fR will be invoked
|
|
when all input has ended.
|
|
The effect is almost as if the contents of \fIxx\fR had been at the end
|
|
of the last file processed,
|
|
but all processing ceases at the next page eject.
|
|
.NH
|
|
Number Registers
|
|
.PP
|
|
A variety of parameters are available to the user as
|
|
predefined \fInumber registers\fR (see Summary, page \n(*%).
|
|
In addition, users may define their own registers.
|
|
Register names are one or two characters long and do not conflict
|
|
with request, macro, or string names.
|
|
Except for certain predefined read-only registers,
|
|
a number register can be read, written, automatically
|
|
incremented or decremented, and interpolated
|
|
into the input in a variety of formats.
|
|
One common use of user-defined registers is to
|
|
automatically number sections, paragraphs, lines, etc.
|
|
A number register may be used any time numerical input is expected or desired
|
|
and may be used in numerical \fIexpressions\fR (§1.4).
|
|
.PP
|
|
Number registers are created and modified using \&\f(CWnr\fR, which
|
|
specifies the name, numerical value, and the auto-increment size.
|
|
Registers are also modified, if accessed
|
|
with an auto-incrementing sequence.
|
|
If the registers \fIx\fR and \fIxx\fR both contain
|
|
@N@ and have the auto-increment size @M@,
|
|
the following access sequences have the effect shown:
|
|
.TS
|
|
center box;
|
|
c2|c2|c
|
|
c2|c2|c2
|
|
l2|c2|c2
|
|
l2|c2|c2
|
|
l2|l2|c2.
|
|
Effect on Value
|
|
Sequence Register Interpolated
|
|
_
|
|
\&\f(CW\en\fIx\fR none @N@
|
|
\&\f(CW\en(\fIxx\fR none @N@
|
|
\&\f(CW\en+\fIx\fR \fIx\fR incremented by @M@ \fIN+M\fR
|
|
\&\f(CW\en-\fIx\fR \fIx\fR decremented by @M@ \fIN-M\fR
|
|
\&\f(CW\en+(\fIxx\fR \fIxx\fR incremented by @M@ \fIN+M\fR
|
|
\&\f(CW\en-(\fIxx\fR \fIxx\fR decremented by @M@ \fIN-M\fR
|
|
.TE
|
|
When interpolated, a number register is converted to
|
|
decimal (default),
|
|
decimal with leading zeros,
|
|
lower-case Roman,
|
|
upper-case Roman,
|
|
lower-case sequential alphabetic,
|
|
or
|
|
upper-case sequential alphabetic
|
|
according to the format specified by \&\f(CWaf\fR.
|
|
.bt "\&\f(CW&nr\fI R \(+-N M\fR" "" "-" "\fBu\fR" "The number register
|
|
@R@ is assigned the value @+- N@
|
|
with respect to the previous value, if any.
|
|
The increment for auto-incrementing is set to @M@.
|
|
.bt "\&\f(CW&af\fI R c\fR" "arabic" "-" "-" "Assign
|
|
format @c@ to register @R@.
|
|
The available formats are:
|
|
.Tm number register format s
|
|
.TS
|
|
center box;
|
|
c2|c
|
|
c2|c
|
|
c2|l.
|
|
Numbering
|
|
Format Sequence
|
|
_
|
|
\&\f(CW1\fR 0, 1, 2, 3, 4, 5, ...
|
|
\&\f(CW001\fR 000, 001, 002, 003, 004, 005, ...
|
|
\&\f(CWi\fR 0, i, ii, iii, iv, v, ...
|
|
\&\f(CWI\fR 0, I, II, III, IV, V, ...
|
|
\&\f(CWa\fR 0, a, b, c, ..., z, aa, ab, ..., zz, aaa, ...
|
|
\&\f(CWA\fR 0, A, B, C, ..., Z, AA, AB, ..., ZZ, AAA, ...
|
|
.TE
|
|
An arabic format having @N@ digits
|
|
specifies a field width of @N@ digits (example 2 above).
|
|
The read-only registers and the width function
|
|
.CW \ew
|
|
(§11.2)
|
|
are always arabic.
|
|
Warning: the value of a number register in a non-Arabic format
|
|
is not numeric, and will not produce the expected results in expressions.
|
|
.IP
|
|
The function
|
|
.CW \eg@x@
|
|
or
|
|
.CW \eg(@xx@
|
|
returns the format of a number register in a form suitable for
|
|
.CW af ;
|
|
it returns nothing if the register has not been used.
|
|
.bt "\&\f(CW&rr\fI R\fR" "-" "ignored" "-" "Remove number register @R@.
|
|
If many registers are being created dynamically, it
|
|
may become necessary to remove unused registers
|
|
to recapture internal storage space for newer registers.
|
|
The register
|
|
.CW .R
|
|
contains the number of number registers still available.
|
|
.NH
|
|
Tabs, Leaders, and Fields
|
|
.sc "Tabs and leaders.
|
|
The \s-1ASCII\s+1 horizontal tab character and the \s-1ASCII\s+1
|
|
\s-1SOH\s+1 (control-A, hereafter called the \fIleader\fR character)
|
|
can both be used to generate either horizontal motion or
|
|
a string of repeated characters.
|
|
The length of the generated entity is governed
|
|
by internal \fItab stops\fR specifiable
|
|
with \&\f(CWta\fR.
|
|
The default difference is that tabs generate motion and leaders generate
|
|
a string of periods;
|
|
\&\f(CWtc\fR and \&\f(CWlc\fR
|
|
offer the choice of repeated character or motion.
|
|
There are three types of internal tab stops\(em\
|
|
\fIleft\fR adjusting, \fIright\fR adjusting,
|
|
and \fIcentering\fR.
|
|
In the following table,
|
|
\fID\fR is the distance from the current position on the \fIinput\fR line
|
|
(where a tab or leader was found)
|
|
to the next tab stop,
|
|
\fInext-string\fR consists
|
|
of the input characters following the tab (or leader) up to the next tab (or leader) or end of line,
|
|
and
|
|
\fIW\fR is the width of \fInext-string\fR.
|
|
.TS
|
|
center box;
|
|
c2|c2|c
|
|
c2|c2|c
|
|
c2|c2|l.
|
|
Tab Length of motion or Location of
|
|
type repeated characters \fInext-string\fR
|
|
_
|
|
Left \fID\fR Following \fID\fR
|
|
Right \fID-W\fR Right adjusted within \fID\fR
|
|
Centered \fID-W/\fR2 Centered on right end of \fID\fR
|
|
.TE
|
|
The length of generated motion is allowed to be negative, but
|
|
that of a repeated character string cannot be.
|
|
Repeated character strings contain an integer number of characters, and
|
|
any residual distance is prepended as motion.
|
|
Tabs or leaders found after the last tab stop are ignored, but may be used
|
|
as \fInext-string\fR terminators.
|
|
.PP
|
|
Tabs and leaders are not interpreted in copy mode.
|
|
\&\f(CW\et\fR and \&\f(CW\ea\fR always generate a non-interpreted
|
|
tab and leader respectively, and
|
|
are equivalent to actual tabs and leaders in copy mode.
|
|
.sc "Fields.
|
|
A \fIfield\fR is contained between
|
|
a pair of \fIfield delimiter\fR characters,
|
|
and consists of substrings
|
|
separated by \fIpadding\fR indicator characters.
|
|
The field length is the distance on the
|
|
\fIinput\fR line from the position where the field begins to the next tab stop.
|
|
The difference between the total length of all the substrings
|
|
and the field length is incorporated as horizontal
|
|
padding space that is divided among the indicated
|
|
padding places.
|
|
The incorporated padding is allowed to be negative.
|
|
For example,
|
|
if the field delimiter is \&\f(CW#\fR and the padding indicator is \&\f(CW^\fR,
|
|
\&\f(CW#^\fIxxx\&\f(CW^\fIright\|\&\f(CW#\fR
|
|
specifies a right-adjusted string with the string \fIxxx\fR centered
|
|
in the remaining space.
|
|
.h1
|
|
.bt "\&\f(CW&ta\fI Nt ...\fR" "0.8; 0.5in" "none" "E,\fBm\fR" "Set tab stops and types.
|
|
\fIt=\&\f(CWR\fR, right adjusting;
|
|
\fIt=\&\f(CWC\fR, centering;
|
|
\fIt\fR absent, left adjusting.
|
|
\*(Tr tab stops are preset every 0.5in.,
|
|
\*(NR every 0.8in.
|
|
The stop values are separated by spaces, and
|
|
a value preceded by \&\f(CW+\fR
|
|
is treated as an increment to the previous stop value.
|
|
.bt "\&\f(CW&tc\fI c\fR" "none" "none" "E" "The tab repetition character
|
|
becomes @c@,
|
|
or is removed, thus specifying motion.
|
|
.bt "\&\f(CW&lc\fI c\fR" "\&\f(CW.\fR" "none" "E" "The leader repetition character
|
|
becomes @c@,
|
|
or is removed, thus specifying motion.
|
|
.bt "\&\f(CW&fc\fI a b\fR" "off" "off" "-" "The field delimiter
|
|
is set to \fIa\fR;
|
|
the padding indicator is set to the space character or to
|
|
\fIb\fR, if given.
|
|
In the absence of arguments the field mechanism is turned off.
|
|
.NH
|
|
Input and Output Conventions and Character Translations
|
|
.sc "Input character translations.
|
|
Ways of inputting the valid character set were
|
|
discussed in §2.1.
|
|
The \s-1ASCII\s+1 control characters horizontal tab (§9.1),
|
|
\s-1SOH\s+1 (§9.1), and backspace (§10.3) are discussed elsewhere.
|
|
The newline delimits input lines.
|
|
In addition,
|
|
\s-1STX\s+1, \s-1ETX\s+1, \s-1ENQ\s+1, \s-1ACK\s+1, and \s-1BEL\s+1
|
|
are accepted,
|
|
and may be used as delimiters or translated into a graphic with \&\f(CWtr\fR (§10.5).
|
|
All others are ignored.
|
|
.PP
|
|
The \fIescape\fR character \&\f(CW\e\fR
|
|
introduces \fIescape sequences\fR,
|
|
which cause the following character to mean
|
|
another character, or to indicate
|
|
some function.
|
|
.nr %% \n(*%-1
|
|
A complete list of such sequences is given in the Summary on page \n(*%.
|
|
The escape character \&\f(CW\e\fR
|
|
should not be confused with the \s-1ASCII\s+1 control character \s-1ESC\s+1.
|
|
The escape character \&\f(CW\e\fR can be input with the sequence \&\f(CW\e\e\fR.
|
|
The escape character can be changed with \&\f(CWec\fR,
|
|
and all that has been said about the default \&\f(CW\e\fR becomes true
|
|
for the new escape character.
|
|
\&\f(CW\ee\fR can be used to print whatever the current escape character is.
|
|
The escape mechanism may be turned off with \&\f(CWeo\fR,
|
|
and restored with \&\f(CWec\fR.
|
|
.h1
|
|
.bt "\&\f(CW&ec\fI c\fR" "\&\f(CW\e\fR" "\&\f(CW\e\fR" "-" "Set escape character
|
|
to \&\f(CW\e\fR, or to @c@, if given.
|
|
.bt "\&\f(CW&eo\fR" "on" "-" "-" "Turn escape mechanism off.
|
|
.sc "Ligatures.
|
|
.lg0
|
|
The set of available ligatures is device and font dependent,
|
|
but is often a subset of
|
|
\&\fBfi\fR, \&\fBfl\fR, \&\fBff\fR, \&\fBffi\fR, and \&\fBffl\fR.
|
|
They may be input by
|
|
\&\f(CW\e(fi\fR, \&\f(CW\e(fl\fR, \&\f(CW\e(ff\fR, \&\f(CW\e(Fi\fR, and \&\f(CW\e(Fl\fR respectively.
|
|
.lg
|
|
The ligature mode is normally on in \*(TR, and automatically invokes
|
|
ligatures during input.
|
|
.h1
|
|
.bt "\&\f(CW&lg\fI N\fR" "on; off" "on" "-" "Ligature mode
|
|
is turned on if @N@ is absent or non-zero,
|
|
and turned off if @N=0@.
|
|
If @N=2@, only the two-character ligatures are automatically invoked.
|
|
Ligature mode is inhibited for
|
|
request, macro, string, register, or file names,
|
|
and in copy mode.
|
|
No effect in \*(NR.
|
|
.sc "Backspacing, underlining, overstriking, etc.
|
|
Unless in copy mode, the \s-1ASCII\s+1 backspace character is replaced
|
|
by a backward horizontal motion having the width of the
|
|
space character.
|
|
Underlining as a form of line-drawing is discussed in §12.4.
|
|
A generalized overstriking function is described in §12.1.
|
|
.PP
|
|
\*(Nr automatically underlines
|
|
characters in the \fIunderline\fR font,
|
|
specifiable with \&\f(CWuf\fR,
|
|
normally that on font position 2.
|
|
In addition to \&\f(CWft\fR and
|
|
.CW \ef@F@ ,
|
|
the underline font may be selected by \&\f(CWul\fR and \&\f(CWcu\fR.
|
|
Underlining is restricted to an output-device-dependent
|
|
subset of reasonable characters.
|
|
.bt "\&\f(CW&ul\fI N\fR" "off" "@N=1@" "E" "Italicize in \*(TR
|
|
(underline in \*(NR) the next @N@
|
|
input text lines.
|
|
Actually, switch to underline font, saving the
|
|
current font for later restoration;
|
|
other font changes within the span of a \&\f(CWul\fR
|
|
will take effect,
|
|
but the restoration will undo the last change.
|
|
Output generated by \&\f(CWtl\fR (§14) is affected by the
|
|
font change, but does not decrement @N@.
|
|
If @N>1@, there is the risk that
|
|
a trap interpolated macro may provide text
|
|
lines within the span;
|
|
environment switching can prevent this.
|
|
.bt "\&\f(CW&cu\fI N\fR" "off" "@N=1@" "E" "Continuous underline.
|
|
A variant
|
|
of \&\f(CWul\fR that causes \fIevery\fR character to be underlined in \*(NR.
|
|
Identical to \&\f(CWul\fR in \*(TR.
|
|
.bt "\&\f(CW&uf\fI F\fR" "Italic" "Italic" "-" "Underline font set to @F@.
|
|
In \*(NR,
|
|
@F@ may not be on position 1.
|
|
.sc "Control characters.
|
|
Both the control character \&\f(CW.\fR and the \fIno-break\fR
|
|
control character \&\f(CW'\fR may be changed.
|
|
Such a change must be compatible with the design
|
|
of any macros used in the span of the change,
|
|
and
|
|
particularly of any trap-invoked macros.
|
|
.bt "\&\f(CW&cc\fI c\fR" "\&\f(CW.\fR" "\&\f(CW.\fR" "E" "The basic control character
|
|
is set to @c@,
|
|
or reset to ``\&\f(CW.\fR''.
|
|
.bt "\&\f(CW&c2\fI c\fR" "\&\f(CW'" "'\fR" "E" "The \fIno-break\fR control character is set
|
|
to @c@, or reset to ``\&\f(CW'\fR''.
|
|
.sc "Output translation.
|
|
One character can be made a stand-in for another character using \&\f(CWtr\fR.
|
|
All text processing (e.g., character comparisons) takes place
|
|
with the input (stand-in) character, which appears to have the width of the final
|
|
character.
|
|
The graphic translation occurs at the moment of output
|
|
(including diversion).
|
|
.bt "\&\f(CW&tr\fI abcd....\fR" "none" "-" "O" "Translate
|
|
\fIa\fR into \fIb\fR, @c@ into \fId\fR, etc.
|
|
If an odd number of characters is given,
|
|
the last one will be mapped into the space character.
|
|
To be consistent, a particular translation
|
|
must stay in effect from \fIinput\fR to \fIoutput\fR time.
|
|
.sc "Transparent throughput.
|
|
An input line beginning with a \&\f(CW\e!\fR is read in copy mode and \fItrans\%parently\fR output
|
|
(without the initial \&\f(CW\e!\fR);
|
|
the text processor is otherwise unaware of the line's presence.
|
|
This mechanism may be used to pass control information to a post-processor
|
|
or to embed control lines in a macro created by a diversion.
|
|
.sc "Transparent output
|
|
The sequence
|
|
.CW \eX'@anything@'
|
|
copies
|
|
.I anything
|
|
to the output, as a device control function of the form
|
|
.CW x
|
|
.CW X
|
|
.I anything
|
|
(§22).
|
|
Escape sequences in
|
|
.I anything
|
|
are processed.
|
|
.sc "Comments and concealed newlines.
|
|
An uncomfortably long input line that must stay
|
|
one line (e.g., a string definition, or nofilled text)
|
|
can be split into several physical lines by ending all but
|
|
the last one with the escape \&\f(CW\e\fR.
|
|
The sequence \&\f(CW\e\fR@newline@ is always ignored,
|
|
except in a comment.
|
|
Comments may be embedded at the end of any line by
|
|
prefacing them with \&\f(CW\e"\fR.
|
|
The newline at the end of a comment cannot be concealed.
|
|
A line beginning with \&\f(CW\e"\fR will appear as a blank line and
|
|
behave like
|
|
.CW ".sp\ 1" ;
|
|
a comment can be on a line by itself by beginning the line with \&\f(CW.\e"\fR.
|
|
.NH
|
|
Local Horizontal and Vertical Motions, and the Width Function
|
|
.sc "Local Motions.
|
|
The functions \&\f(CW\ev'\fIN\&\f(CW'\fR and
|
|
\&\f(CW\eh'\fIN\&\f(CW'\fR
|
|
can be used for \fIlocal\fR vertical and horizontal motion respectively.
|
|
The distance @N@ may be negative; the positive directions
|
|
are rightward and downward.
|
|
A local motion is one contained within a line.
|
|
To avoid unexpected vertical dislocations, it is necessary that
|
|
the net vertical local motion within a word in filled text
|
|
and otherwise within a line balance to zero.
|
|
The escape sequences providing local motion are
|
|
summarized in the following table.
|
|
.ds Y \0\0\0
|
|
.KS
|
|
.TS
|
|
center box;
|
|
c2|cs2||c2|cs2
|
|
c1|c2c2||c2|c2c2.
|
|
Vertical Effect in Horizontal Effect in
|
|
Local Motion \*(TR \*(NR Local Motion \*(TR \*(NR
|
|
_
|
|
.sp.4
|
|
.TC
|
|
l2|ls2||l2|ls2.
|
|
\&\f(CW\*Y\ev'\fIN\|\f(CW'\fR Move distance @N@ \
|
|
\&\f(CW\*Y\eh'\fIN\|\f(CW'\fR Move distance @N@
|
|
.TC
|
|
_2|_2_2||l2|ls2.
|
|
x x x \&\f(CW\*Y\e\fP\f2space\fP Unpaddable space-size space
|
|
.TC
|
|
l2|l2|l2||l2|ls2.
|
|
\&\f(CW\*Y\eu\fR ½ em up ½ line up \&\f(CW\*Y\e0\fR Digit-size space
|
|
.TC
|
|
l2|l2|l2||_2|_2_2.
|
|
\&\f(CW\*Y\ed\fR ½ em down ½ line down x x x
|
|
.TC
|
|
l2|l2|l2||l2|l2|l2.
|
|
\&\f(CW\*Y\er\fR 1 em up 1 line up \&\f(CW\*Y\e|\fR 1/6 em space ignored
|
|
\&\f(CW\*Y\e^\fR 1/12 em space ignored
|
|
.sp.4
|
|
.TE
|
|
.KE
|
|
As an example,
|
|
\&\f(CWE\s-2\v'-.4m'2\v'.4m'\s+2\fR
|
|
could be generated by a sequence of size changes and motions:
|
|
\&\f(CWE\es-2\ev'-0.4m'2\ev'0.4m'\es+2\fR;
|
|
note that
|
|
the 0.4 em vertical motions are at the smaller size.
|
|
.sc "Width Function.
|
|
The \fIwidth\fR function \&\f(CW\ew'\fIstring\&\f(CW'\fR
|
|
generates the numerical width of \fIstring\fR (in basic units).
|
|
Size and font changes may be embedded in \fIstring\fR,
|
|
and will not affect the current environment.
|
|
For example,
|
|
\&\&\f(CW.ti\ -\ew'\efB1.\ 'u\fR could be used to
|
|
temporarily indent leftward a distance equal to the
|
|
size of the string ``\&\f(CW1.\ \fR'' in font
|
|
.CW B .
|
|
.PP
|
|
The width function also sets three number registers.
|
|
The registers \&\f(CWst\fR and \&\f(CWsb\fR are set respectively to the highest and
|
|
lowest extent of \fIstring\fR relative to the baseline;
|
|
then, for example,
|
|
the total height of the string is \&\f(CW\en(stu-\en(sbu\fR.
|
|
In \*(TR the number register \&\f(CWct\fR is set to a value
|
|
between 0 and 3.
|
|
The value
|
|
0 means that all of the characters in \fIstring\fR were short lower
|
|
case characters without descenders (like \&\f(CWe\fR);
|
|
1 means that at least one character has a descender (like \&\f(CWy\fR);
|
|
2 means that at least one character is tall (like \&\f(CWH\fR);
|
|
and 3 means that both tall characters and characters with
|
|
descenders are present.
|
|
.sc "Mark horizontal place.
|
|
The function \&\f(CW\ek\fIx\fR causes the current horizontal
|
|
position in the \fIinput line\fR to be stored in register \fIx\fR.
|
|
For example,
|
|
the construction \&\f(CW\ekx\fIword\f(CW\eh'|\enxu+3u'\fIword\&\f(CW\fR
|
|
will embolden \fIword\fR by backing up to almost its beginning and overprinting it,
|
|
resulting in \kz\fIword\fR\h'|\nzu+3u'\fIword\fR.
|
|
.NH
|
|
Overstrike, Bracket, Line-drawing, Graphics, and Zero-width Functions
|
|
.sc "Overstriking.
|
|
Automatically centered overstriking of up to nine characters
|
|
is provided by the \fIoverstrike\fR function
|
|
\&\f(CW\eo'\fIstring\&\f(CW\|'\fR.
|
|
The characters in \fIstring\fR are overprinted with centers aligned; the total width
|
|
is that of the widest character.
|
|
\fIstring\fR may not contain local vertical motion.
|
|
As examples,
|
|
\&\f(CW\eo'e\e''\fR produces \o'e\'', and
|
|
\&\f(CW\eo'\e(mo\e(sl'\fR produces \o'\(mo\(sl'.
|
|
.sc "Zero-width characters.
|
|
The function
|
|
.CW \ez@c@
|
|
will output @c@ without spacing over
|
|
it, and can be used to produce left-aligned overstruck
|
|
combinations.
|
|
As examples,
|
|
\&\f(CW\ez□+\fR will produce \z□+, and
|
|
\&\f(CW\e(br\ez\e(rn\e(ul\e(br\fR will produce a small
|
|
badly constructed box \&\(br\z\(rn\(ul\(br\|.
|
|
.sc "Large Brackets.
|
|
The Special Font usually contains a number of bracket construction pieces
|
|
\|\|\(lt\|\|\(lb\|\|\(rt\|\|\(rb\|\|\(lk\|\|\(rk\|\|\(bv\|\|\(lf\|\|\(rf\|\|\(lc\|\|\(rc\|\|
|
|
that can be combined into various bracket styles.
|
|
The function \&\f(CW\eb'\fIstring\&\f(CW\|'\fR may be used to pile
|
|
up vertically the characters in \fIstring\fR
|
|
(the first character on top and the last at the bottom);
|
|
the characters are vertically separated by 1 em and the total
|
|
pile is centered 1/2 em above the current baseline
|
|
(½ line in \*(NR).
|
|
For example,
|
|
.P1
|
|
\eb'\e(lc\e(lf'E\eb'\e(rc\e(rf'\ex'-0.5m'\ex'0.5m'
|
|
.P2
|
|
produces
|
|
\x'-.5m'\x'.5m'\b'\(lc\(lf'E\b'\(rc\(rf'.
|
|
.sc "Line drawing.
|
|
.tr &&
|
|
The function \&\f(CW\el'\fINc\f(CW'\fR (backslash-ell) draws a string of repeated @c@'s towards the right for a distance @N@.
|
|
If @c@ looks like a continuation of
|
|
an expression for @N@, it may be insulated from @N@ with \&\f(CW\e&\fR.
|
|
If @c@ is not specified, the \&\f(CW\(ru\fR (baseline rule) is used
|
|
(underline character in \*(NR).
|
|
If @N@ is negative, a backward horizontal motion
|
|
of size @N@ is made before drawing the string.
|
|
Any space resulting from @N@/(size of @c@) having a remainder is put at the beginning (left end)
|
|
of the string.
|
|
If @N@ is less than the width of @c@,
|
|
a single @c@ is centered on a distance @N@.
|
|
In the case of characters
|
|
that are designed to be connected, such as
|
|
baseline-rule\ \&\f(CW\(ru\fR\|,
|
|
under-rule\ \&\f(CW\(ul\fR\|,
|
|
and
|
|
root-en\ \&\f(CW\(rn\fR\|,
|
|
the remainder space is covered by overlapping.
|
|
As an example, a macro to underscore a string can be written
|
|
.tr &.
|
|
.P1
|
|
.ne 2.1
|
|
&de us
|
|
\e\e$1\e\|l\|'|0\e(ul'
|
|
&&
|
|
.P2
|
|
.ne2.1
|
|
.de xu
|
|
\\$1\l'|0\(ul'
|
|
..
|
|
or one to draw a box around a string
|
|
.P1
|
|
&de bx
|
|
\e(br\e|\e\e$1\e|\e(br\e\|l\|'|0\e(rn'\e\|l\|'|0\e(ul'
|
|
&&
|
|
.P2
|
|
.de bx
|
|
\(br\|\\$1\|\(br\l'|0\(rn'\l'|0\(ul'
|
|
..
|
|
such that
|
|
.P1
|
|
&ul "underlined words"
|
|
.P2
|
|
and
|
|
.P1
|
|
&bx "words in a box"
|
|
.P2
|
|
yield
|
|
.xu "underlined words"
|
|
and
|
|
.bx "words in a box"
|
|
\h'-\w'.'u'.
|
|
.PP
|
|
The function \&\f(CW\eL'\fINc\&\f(CW'\fR draws a vertical line consisting
|
|
of the (optional) character @c@ stacked vertically apart 1\|em
|
|
(1 line in \*(NR),
|
|
with the first two characters overlapped,
|
|
if necessary, to form a continuous line.
|
|
The default character is the \fIbox rule\fR \|\(br\| (\&\f(CW\|\e(br\fR);
|
|
the other suitable character is the \fIbold vertical\fR \|\(bv\| (\&\f(CW\|\e(bv\fR).
|
|
The line is begun without any initial motion relative to the
|
|
current baseline.
|
|
A positive @N@ specifies a line drawn downward and
|
|
a negative @N@ specifies a line drawn upward.
|
|
After the line is drawn no compensating
|
|
motions are made;
|
|
the instantaneous baseline is at the end of the line.
|
|
.PP
|
|
.de eb
|
|
.sp -1
|
|
.nf
|
|
\h'-.5n'\L'|\\nzu-1'\l'\\n(.lu+1n\(ul'\L'-|\\nzu+1'\l'|0u-.5n\(ul'
|
|
.fi
|
|
..
|
|
.ne 2i
|
|
.mk z
|
|
.nr z \nz+1
|
|
The horizontal and vertical line drawing functions may be used
|
|
in combination to produce large boxes.
|
|
The zero-width \fIbox-rule\fR and the ½-em wide \fIunder-rule\fR
|
|
were designed to form corners when using 1-em vertical
|
|
spacings.
|
|
For example the macro
|
|
.nr x \n(DV
|
|
.nr DV 0
|
|
.P1 .15i
|
|
.ps -1
|
|
\&.de eb
|
|
\&.sp -1 \e"compensate for next automatic baseline spacing
|
|
\&.nf \e"avoid possibly overflowing word buffer
|
|
\&\eh'-.5n'\eL'|\e\enau-1'\el'\e\en(.lu+1n\e(ul'\eL'-|\e\enau+1'\el'|0u-.5n\e(ul'
|
|
\&.fi
|
|
\&..
|
|
.ps +1
|
|
.P2
|
|
.nr DV \nx
|
|
will draw a box around some text whose beginning vertical place was
|
|
saved in number register \fIa\fR
|
|
(e.g., using \&\f(CW.mk\ a\fR)
|
|
as was done for this paragraph.
|
|
.eb
|
|
.sc "Graphics.
|
|
The function
|
|
.CW \eD'@c...@'
|
|
draws a graphic object of type @c@
|
|
according to a sequence of parameters,
|
|
which are generally pairs of numbers.
|
|
.IP
|
|
.nf
|
|
.ta 1.7i
|
|
\f(CW\eD'l @dh~ dv@' \f1draw line from current position by @dh,~dv@\f(CW
|
|
\f(CW\eD'c @d@' \f1draw circle of diameter @d@ with left side at current position\f(CW
|
|
\f(CW\eD'e @d sub 1 d sub 2@' \f1draw ellipse of diameters @d sub 1@ and @d sub 2@\f(CW
|
|
\f(CW\eD'a @dh sub 1~ dv sub 1~ dh sub 2~ dv sub 2@'\f(CW \f1draw arc from current position to @dh sub 1 +dh sub 2@, @dv sub 1 +dv sub 2@,\f(CW
|
|
\f1with center at @dh sub 1 ,~ dv sub 1@ from current position\f(CW
|
|
\f(CW\eD'~ @dh sub 1 dv sub 1 dh sub 2 dv sub 2 "..."@'\f(CW \f1draw B-spline from current position by @dh sub 1, dv sub 1@,\f(CW
|
|
\f1then by @dh sub 2 , dv sub 2@, then by @dh sub 2 , dv sub 2@, then ...\f(CW
|
|
.LP
|
|
For example,
|
|
.CW "\eD'e0.2i 0.1i'"
|
|
draws the ellipse
|
|
\D'e.2i .1i'\|,
|
|
and
|
|
.CW "\eD'l.2i -.1i'\eD'l.1i .1i'"
|
|
the line
|
|
\D'l.2i -.1i'\D'l.1i .1i'\|.
|
|
A
|
|
.CW \\eD
|
|
with an unknown @c@ is processed and copied through to the output
|
|
for unspecified interpretation;
|
|
coordinates are interpreted alternately as horizontal and vertical
|
|
values.
|
|
.PP
|
|
Numbers taken as horizontal (first, third, etc.) have default scaling of ems;
|
|
vertical numbers (second, fourth, etc.) have default scaling of @V^@s (§1.3).
|
|
The position after a graphical object has been drawn is
|
|
at its end; for circles and ellipses, the ``end''
|
|
is at the right side.
|
|
.NH
|
|
Hyphenation.
|
|
.PP
|
|
Automatic hyphenation may be switched off and on.
|
|
When switched on with \&\f(CWhy\fR,
|
|
several variants may be set.
|
|
A \fIhyphenation indicator\fR character may be embedded in a word to
|
|
specify desired hyphenation points,
|
|
or may be prefixed to suppress hyphenation.
|
|
In addition,
|
|
the user may specify a small list of exception words.
|
|
.PP
|
|
Only words that consist of a central alphabetic string
|
|
surrounded by (usually null) non-alphabetic strings
|
|
are candidates for automatic hyphenation.
|
|
Words that contain hyphens
|
|
(minus),
|
|
em-dashes (\&\f(CW\e(em\fR),
|
|
or hyphenation indicator characters
|
|
are always subject to splitting after those characters,
|
|
whether automatic hyphenation is on or off.
|
|
.bt "\&\f(CW&nh\fR" "hyphenate" "-" "E" "Automatic hyphenation is turned off.
|
|
.bt "\&\f(CW&hy\fP@~N@" "on, @N=1@" "on, @N=1@" "E" "Automatic hyphenation is turned on
|
|
for @N >= 1@, or off for @N=0@.
|
|
If @N=2@, last lines (ones that will cause a trap)
|
|
are not hyphenated.
|
|
For @N=4@ and 8, the last and first two characters
|
|
respectively of a word are not split off.
|
|
These values are additive;
|
|
i.e., @N=14@ will invoke all three restrictions.
|
|
.bt "\&\f(CW&hc\fI c\fR" "\&\f(CW\e%" "\e%\fR" "E" "Hyphenation indicator character is set
|
|
to @c@ or to the default \&\f(CW\e%\fR.
|
|
The indicator does not appear in the output.
|
|
.bt "\&\f(CW&hw\fI word ...\fR" "" "ignored" "-" "Specify
|
|
hyphenation points in words
|
|
with embedded minus signs.
|
|
Versions of a word with terminal \fIs\fR are implied;
|
|
i.e.,
|
|
.CW dig-it
|
|
implies
|
|
.CW dig-its .
|
|
This list is examined initially and after
|
|
each suffix stripping.
|
|
The space available is small.
|
|
.NH
|
|
Three-Part Titles.
|
|
.PP
|
|
The titling function \&\f(CWtl\fR provides for automatic placement
|
|
of three fields at the left, center, and right of a line
|
|
with a title length
|
|
specifiable with \&\f(CWlt\fR.
|
|
\&\f(CWtl\fR may be used anywhere, and is independent of the
|
|
normal text collecting process.
|
|
A common use is in header and footer macros.
|
|
.h1
|
|
.bt "\&\f(CW&tl '\fIleft\fP'\fIcenter\fP'\fIright\fP'\fR" "-" "-" "" "The strings
|
|
\fIleft\fR, \fIcenter\fR, and \fIright\fR are
|
|
respectively left-adjusted, centered, and right-adjusted
|
|
in the current title length.
|
|
Any of the strings may be empty,
|
|
and overlapping is permitted.
|
|
If the page-number character (initially \&\f(CW%\fR) is found within any of the fields it is replaced
|
|
by the current page number in the format assigned to register \&\f(CW%\fR.
|
|
Any character may be used in place of
|
|
.CW '
|
|
as the string delimiter.
|
|
.bt "\&\f(CW&pc\fI c\fR" "\&\f(CW%\fR" "off" "-" "The page number character is set to @c@,
|
|
or removed.
|
|
The page number register remains \&\f(CW%\fR.
|
|
.bt "\&\f(CW<\fI \(+-N\fR" "6.5\|in" "previous" "E,\fBm\fR" "Length of title
|
|
is set to @+- N@.
|
|
The line length and the title length are independent.
|
|
Indents do not apply to titles; page offsets do.
|
|
.NH
|
|
Output Line Numbering.
|
|
.PP
|
|
.ll -\w'0000'u
|
|
.nm 1 3
|
|
Automatic sequence numbering of output lines may be
|
|
requested with \&\f(CWnm\fR.
|
|
When in effect,
|
|
a three-digit, arabic number plus a digit-space
|
|
is prefixed to output text lines.
|
|
The text lines are thus offset by four digit-spaces,
|
|
and otherwise retain their line length;
|
|
a reduction in line length may be desired to keep the right margin
|
|
aligned with an earlier margin.
|
|
Blank lines, other vertical spaces, and lines generated by \&\f(CWtl\fR
|
|
are not numbered.
|
|
Numbering can be temporarily suspended with \&\f(CWnn\fR,
|
|
or with an \&\f(CW.nm\fR followed by a later \&\f(CW.nm +0\fR.
|
|
In addition,
|
|
a line number indent \fII\fR, and the number-text separation \fIS\fR
|
|
may be specified in digit-spaces.
|
|
Further, it can be specified that only those line numbers that are
|
|
multiples of some number @M@ are to be printed (the others will appear
|
|
as blank number fields).
|
|
.br
|
|
.nm
|
|
.ll
|
|
.bt "\&\f(CW&nm\fI \(+-N M S I\fR" "" "off" "E" "Line number mode.
|
|
If @+- N@ is given,
|
|
line numbering is turned on,
|
|
and the next output line numbered is numbered @+- N@.
|
|
Default values are @M=1@, @S=1@, and @I=0@.
|
|
Parameters corresponding to missing arguments are unaffected;
|
|
a non-numeric argument is considered missing.
|
|
In the absence of all arguments, numbering is turned off;
|
|
the next line number is preserved for possible further use
|
|
in number register \&\f(CWln\fR.
|
|
.bt "\&\f(CW&nn\fI N\fR" "-" "@N=1@" "E" "The next @N@ text output lines are not
|
|
numbered.
|
|
.PP
|
|
.ll -\w'0000'u
|
|
.nm +0
|
|
As an example, the paragraph portions of this section
|
|
are numbered with \fIM=\fR\|3:
|
|
\&\&\f(CW.nm\ 1\ 3\fR was placed at the beginning;
|
|
\&\&\f(CW.nm\fR was placed at the end of the first paragraph;
|
|
and \&\f(CW.nm\ +0\fR was placed in front of this paragraph;
|
|
and \&\f(CW.nm\fR finally placed at the end.
|
|
Line lengths were also changed (by \&\f(CW\ew'0000'u\fR) to keep the right side aligned.
|
|
Another example is
|
|
.CW .nm
|
|
.CW +5
|
|
.CW 5
|
|
.CW x
|
|
.CW 3 ,
|
|
which turns on numbering with the line number of the next
|
|
line to be 5 greater than the last numbered line,
|
|
with @M=5@, with spacing \fIS\fR untouched, and with the indent \fII\fR set to 3.
|
|
.br
|
|
.ll
|
|
.nm
|
|
.NH
|
|
Conditional Acceptance of Input
|
|
.PP
|
|
In the following,
|
|
@c@ is a one-character built-in \fIcondition\fR name,
|
|
\&\f(CW!\fR signifies \fInot\fR,
|
|
@N@ is a numerical expression,
|
|
\fIstring1\fR and \fIstring2\fR are strings delimited by any non-blank, non-numeric character not in the strings,
|
|
and
|
|
\fIanything\fR represents what is conditionally accepted.
|
|
.bt "\&\f(CW&if\fI c anything\fR" "-" "-" "" "If condition
|
|
@c@ true, accept \fIanything\fR as input;
|
|
in multi-line case use \e{\fIanything\|\fR\e}.
|
|
.bt "\&\f(CW&if !\fIc anything\fR" "-" "-" "" "If condition @c@ false, accept \fIanything\fR.
|
|
.bt "\&\f(CW&if\fI N anything\fR" "" "-" "\fBu\fR" "If expression @N@ > 0, accept \fIanything\fR.
|
|
.bt "\&\f(CW&if !\fIN anything\fR" "" "-" "\fBu\fR" "If expression @N@ ≤ 0 [sic], accept \fIanything\fR.
|
|
.bt "\&\f(CW&if '\fIstring1\f(CW'\fIstring2\f(CW'\fI anything\fR" "-" "" "" "If \fIstring1\fR identical to \fIstring2\fR,
|
|
accept \fIanything\fR.
|
|
.bt "\&\f(CW&if !'\fIstring1\f(CW'\fIstring2\f(CW'\fI anything\fR" "-" "" "" "If \fIstring1\fR not identical to \fIstring2\fR,
|
|
accept \fIanything\fR.
|
|
.bt "\&\f(CW&ie\fI c anything\fR" "" "-" "\fBu\fR" "If portion of if-else;
|
|
all of the forms for \&\f(CWif\fR above are valid.
|
|
.bt "\&\f(CW&el\fI anything\fR" "-" "-" "" "Else portion of if-else.
|
|
.PP
|
|
The built-in condition names are:
|
|
.TS
|
|
center box;
|
|
c2|c2
|
|
c2|c2
|
|
c2|l2.
|
|
Condition
|
|
Name True If
|
|
_
|
|
\&\f(CWo\fR Current page number is odd
|
|
\&\f(CWe\fR Current page number is even
|
|
\&\f(CWt\fR Formatter is \*(TR
|
|
\&\f(CWn\fR Formatter is \*(NR
|
|
.TE
|
|
If the condition @c@ is true, or if the number @N@ is greater than zero,
|
|
or if the strings compare identically (including motions and character size and font),
|
|
\fIanything\fR is accepted as input.
|
|
If a \&\f(CW!\fR precedes the condition, number, or string comparison,
|
|
the sense of the acceptance is reversed.
|
|
.PP
|
|
Any spaces between the condition and the beginning of \fIanything\fR are skipped over.
|
|
The \fIanything\fR can be either a single input line (text, macro, or whatever)
|
|
or a number of input lines.
|
|
In the multi-line case,
|
|
the first line must begin with a left delimiter \&\f(CW\e{\fR and
|
|
the last line must end with a right delimiter \&\f(CW\e}\fR.
|
|
.PP
|
|
The request \&\f(CWie\fR (if-else) is identical to \&\f(CWif\fR
|
|
except that the acceptance state is remembered.
|
|
A subsequent and matching \&\f(CWel\fR (else) request then uses the reverse sense of that state.
|
|
\&\f(CWie\fR-\&\f(CWel\fR pairs may be nested.
|
|
.PP
|
|
Some examples are:
|
|
.P1
|
|
&if e .tl '\|Even Page %'''
|
|
.P2
|
|
which outputs a title if the page number is even; and
|
|
.P1
|
|
&ie \en%>1 \e{\e
|
|
\&' sp 0.5i
|
|
& tl 'Page %'''
|
|
\&' sp |1.2i \e}
|
|
&el .sp |2.5i
|
|
.P2
|
|
which treats page 1 differently from other pages.
|
|
.NH
|
|
Environment Switching.
|
|
.PP
|
|
A number of the parameters that
|
|
control the text processing are gathered together into an
|
|
\fIenvironment\fR, which can be switched by the user.
|
|
The environment parameters are those associated
|
|
with requests noting E in their \fINotes\fR column;
|
|
in addition, partially collected lines and words are in the environment.
|
|
Everything else is global; examples are page-oriented parameters,
|
|
diversion-oriented parameters, number registers, and macro and string definitions.
|
|
All environments are initialized with default parameter values.
|
|
.bt "\&\f(CW&ev\fI N\fR" "@N=0@" "previous" "-" "Environment switched to
|
|
environment @0 <= N <= 2@.
|
|
Switching is done in push-down fashion so that
|
|
restoring a previous environment \fImust\fR be done with \&\f(CW.ev\fR
|
|
rather than specific reference.
|
|
Note that what is pushed down and restored is the environment
|
|
.I number,
|
|
not its contents.
|
|
.NH
|
|
Insertions from the Standard Input
|
|
.PP
|
|
The input can be temporarily switched to the system standard input
|
|
with \&\f(CWrd\fR,
|
|
which will switch back when two consecutive newlines
|
|
are found (the extra blank line is not used).
|
|
This mechanism is intended for insertions in form-letter-like documentation.
|
|
The standard input can be the user's keyboard,
|
|
a pipe, or a file.
|
|
.bt "\&\f(CW&rd\fI prompt\fR" "-" "\fIprompt=\fR\s-1BEL\s+1" "-" "Read insertion
|
|
from the standard input until two newlines in a row are found.
|
|
If the standard input is the user's keyboard, \fIprompt\fR (or a \s-1BEL\s+1)
|
|
is written onto the standard output.
|
|
\&\f(CWrd\fR behaves like a macro,
|
|
and arguments may be placed after \fIprompt\fR.
|
|
.bt "\&\f(CW&ex\fR" "-" "-" "-" "Exit from \*(NR/\*(TR.
|
|
Text processing is terminated exactly as if all input had ended.
|
|
.PP
|
|
If insertions are to be
|
|
taken from the terminal keyboard while output is being printed
|
|
on the terminal, the command line option \&\f(CW-q\fR will turn off the echoing
|
|
of keyboard input and prompt only with \s-1BEL\s+1.
|
|
The regular input and insertion input cannot
|
|
simultaneously come from the standard input.
|
|
.PP
|
|
As an example,
|
|
multiple copies of a form letter may be prepared by entering the insertions
|
|
for all the copies in one file to be used as the standard input,
|
|
and causing the file containing the letter to reinvoke itself with \&\f(CWnx\fR (§19);
|
|
the process would ultimately be ended by an \&\f(CWex\fR in the insertion file.
|
|
.NH
|
|
Input/Output File Switching
|
|
.bt "\&\f(CW&so\fI filename\fR" "" "-" "-" "Switch source file.
|
|
The top input (file reading) level is switched to \fIfilename\fR.
|
|
When the new file ends,
|
|
input is again taken from the original file.
|
|
\&\f(CWso\fR's may be nested.
|
|
.bt "\&\f(CW&nx\fI filename\fR" "" "end-of-file" "-" "Next file is \fIfilename\fR.
|
|
The current file is considered ended, and the input is immediately switched
|
|
to \fIfilename\fR.
|
|
.bt "\&\f(CW&sy\fI string\fR" "" "-" "-" "Execute program from \fIstring\fR,
|
|
which is the rest of the input line.
|
|
The output is not collected automatically.
|
|
The number register
|
|
.CW $$ ,
|
|
which contains the process id of the \*(TR process,
|
|
may be useful in generating unique filenames for output.
|
|
.bt "\&\f(CW&pi\fI string\fR" "" "-" "-" "Pipe output to \fIstring\fR,
|
|
which is the rest of the input line.
|
|
This request must occur before any printing occurs;
|
|
typically it is the first line of input.
|
|
.bt "\&\f(CW&cf\fI filename\fR" "" "-" "-" "Copy
|
|
contents of file
|
|
.I filename
|
|
to output, completely unprocessed.
|
|
The file is assumed to contain something meaningful
|
|
to subsequent processes.
|
|
.NH
|
|
Miscellaneous
|
|
.br
|
|
.mc \s12\(br\s0
|
|
.bt "\&\f(CW.mc\fI c N\fR" - off E,\fBm\fR "Specifies
|
|
that a \fImargin\fR character @c@ appear a distance
|
|
@N@ to the right of the right margin
|
|
after each non-empty text line (except those produced by \&\f(CWtl\fR).
|
|
If the output line is too long (as can happen in nofill mode)
|
|
the character will be appended to the line.
|
|
If @N@ is not given, the previous @N@ is used; the initial @N@ is
|
|
0.2 inches in \*(NR and 1 em in \*(TR.
|
|
The margin character used with this paragraph was a 12-point box-rule.
|
|
.br
|
|
.mc
|
|
.bt "\&\f(CW.tm\fI string\fR" "-" "newline" "-" "After skipping initial blanks,
|
|
\fIstring\fR (rest of the line) is read in copy mode
|
|
and written on the standard error.
|
|
.bt "\&\f(CW&ab\fI string\fR" "-" "newline" "-" "After skipping initial blanks,
|
|
\fIstring\fR (rest of the line) is read in copy mode
|
|
and written on the standard error.
|
|
\*(Tr or \*(NR then exit.
|
|
.bt "\&\f(CW.ig\fI yy\fR" "-" "\fI.yy=\&\f(CW..\fR" "-" "Ignore
|
|
input lines.
|
|
\&\f(CWig\fR behaves exactly like \&\f(CWde\fR (§7) except that the
|
|
input is discarded.
|
|
The input is read in copy mode, and any auto-incremented
|
|
registers will be affected.
|
|
.bt "\&\f(CW.lf\fI N filename\fR" "" "-" "-" "Set
|
|
line number to @N@ and filename to @filename@
|
|
for purposes of subsequent error messages, etc.
|
|
The number register [sic]
|
|
.CW .F
|
|
contains the name of the current input file,
|
|
as set by command line argument,
|
|
.CW so ,
|
|
.CW nx ,
|
|
or
|
|
.CW lf .
|
|
The number register
|
|
.CW .c
|
|
contains the number of input lines read from the current file,
|
|
again perhaps as modified by
|
|
.CW lf .
|
|
.CW
|
|
.bt "\&\f(CW.pm\fI t\fR" "-" "all" "-" "Print macros.
|
|
The names and sizes of all of the defined macros and strings are printed
|
|
on the standard error;
|
|
if \fIt\fR is given, only the total of the sizes is printed.
|
|
The sizes is given in blocks
|
|
of 128 characters.
|
|
.bt "\&\f(CW.fl\fR" - - B "Flush output buffer.
|
|
Force output, including any pending position information.
|
|
......
|
|
.NH
|
|
Output and Error Messages.
|
|
.PP
|
|
The output from \&\f(CWtm\fR, \&\f(CWpm\fR, and the prompt from \&\f(CWrd\fR,
|
|
as well as various error messages, are written onto
|
|
the standard error.
|
|
The latter is different from the standard output,
|
|
where formatted text goes.
|
|
By default, both are written onto the user's terminal,
|
|
but they can be independently redirected.
|
|
.PP
|
|
Various error conditions may occur during
|
|
the operation of \*(NR and \*(TR.
|
|
Certain less serious errors having only local impact do not
|
|
cause processing to terminate.
|
|
Two examples are \fIword overflow\fR, caused by a word that is too large
|
|
to fit into the word buffer (in fill mode), and
|
|
\fIline overflow\fR, caused by an output line that grew too large
|
|
to fit in the line buffer.
|
|
In both cases, a message is printed, the offending excess
|
|
is discarded,
|
|
and the affected word or line is marked at the point of truncation
|
|
with a \(** in \*(NR and a \(lh in \*(TR.
|
|
Processing continues if possible,
|
|
on the grounds that output useful for debugging may be produced.
|
|
If a serious error occurs, processing terminates,
|
|
and a message is printed, along with a list of the macro names currently active.
|
|
Examples of serious errors include the inability to create, read, or write files,
|
|
and the exceeding of certain internal limits that
|
|
make future output unlikely to be useful.
|
|
.NH
|
|
Output Language
|
|
.PP
|
|
\*(Tr
|
|
produces its output in a language that is independent of any
|
|
specific output device,
|
|
except that the numbers in it have been computed on the basis
|
|
of the resolution of the device,
|
|
and the sizes, fonts, and characters that that device can print.
|
|
Nevertheless it is quite possible to interpret that output
|
|
on a different device, within the latter's capabilities.
|
|
.IP
|
|
.nf
|
|
.ta .7i
|
|
@cw s n@ set point size to @n@
|
|
@cw f n@ set font to @n@
|
|
@cw c c@ print character @c@
|
|
@cw C name@ print the character called @name@; terminate @name@ by white space
|
|
@cw N n@ print character @n@ on current font
|
|
@cw H n@ go to absolute horizontal position \f2n\fP (@n >= 0@)
|
|
@cw V n@ go to absolute vertical position \f2n\fP (@n >= 0@, down is positive)
|
|
@cw h n@ go \f2n\fP units horizontally; @n < 0@ is to the left
|
|
@cw v n@ go \f2n\fP units vertically; @n < 0@ is up
|
|
@nnc@ move right \f2nn\fP, then print \s-1UTF\s0 character \f2c\fP; \f2nn\fP must be exactly 2 digits
|
|
@cw p n@ new page \f2n\fP begins\(emset vertical position to 0
|
|
@cw n b~a@ end of line (information only\(emno action); \f2b\fP = space before line, \f2a\fP = after
|
|
@cw w@ paddable word space (information only\(emno action)
|
|
@cw D c@ ...\en graphics function @c@; see below
|
|
@cw x@ ...\en device control functions; see below
|
|
@cw "#"@ ...\en comment
|
|
.LP
|
|
All position values are in units.
|
|
Sequences that end in digits must be followed by a non-digit.
|
|
Blanks, tabs and newlines may occur as separators
|
|
in the input, and are mandatory to separate constructions
|
|
that would otherwise be confused.
|
|
Graphics functions, device control functions, and comments extend to the
|
|
end of the line they occur on.
|
|
.PP
|
|
The device control and graphics commands are intended as open-ended
|
|
families, to be expanded as needed.
|
|
The graphics functions coincide directly with the
|
|
.CW \eD
|
|
sequences:
|
|
.IP
|
|
.nf
|
|
.ta 1.7i
|
|
@cw Dl@ \f2dh dv\fP draw line from current position by @dh,~ dv@
|
|
@cw Dc@ \f2d\fP draw circle of diameter \f2d\fP with left side here
|
|
@cw De@ @dh sub 1~dv sub 2@ draw ellipse of diameters @dh sub 1@ and @ dv sub 2@\fP
|
|
@cw Da ~dh sub 1~ dv sub 1 ~ dh sub 2 ~dv sub 2@ draw arc from current position to @dh sub 1 +dh sub 2 ,~ dv sub 1 +dv sub 2@,
|
|
center at @dh sub 1 ,~ dv sub 1@ from current position
|
|
@cw "D~" ~dh sub 1 ~dv sub 1 ~dh sub 2 ~dv sub 2@ ... draw B-spline from current position to @dh sub 1 ,~ dv sub 1@,
|
|
then to @dh sub 2 , ~dv sub 2@, then to ...
|
|
@cw "D"z ~dh sub 1 ~dv sub 1 ~dh sub 2 ~dv sub 2@ ... for any other @z@ is uninterpreted
|
|
.LP
|
|
In all of these, @dh, ~dv@ is an increment on the current horizontal and
|
|
vertical position,
|
|
with down and right positive.
|
|
All distances and dimensions are in units.
|
|
.PP
|
|
The device control functions begin with
|
|
.CW x ,
|
|
then a command, then other parameters.
|
|
.IP
|
|
.ta .8i 1.2i
|
|
.nf
|
|
.ft CW
|
|
x T \f2s\fP \f1name of typesetter is @s@\f(CW
|
|
x r \f2n h v\fP \f1resolution is @n@ units/inch;\f(CW
|
|
\f1@h@ = minimum horizontal motion, @v@ = minimum vertical\f(CW
|
|
x i \f1initialize\fP
|
|
x f \f2n s\fP \f1mount font @s@ on font position @n@\f(CW
|
|
x p \f1pause\(emcan restart\f(CW
|
|
x s \f1stop\(emdone forever\f(CW
|
|
x t \f1generate trailer information, if any\f(CW
|
|
x H \f2n\fP \f1set character height to @n@\f(CW
|
|
x S \f2n\fP \f1set slant to @n@\f(CW
|
|
x X \f2any\fP \f1generated by the \&\f(CW\eX\fP function\f(CW
|
|
x \f2any\fP \f1to be ignored if not recognized\f(CW
|
|
.LP
|
|
Subcommands like
|
|
.CW i '' ``
|
|
may be spelled out like
|
|
.CW init ''. ``
|
|
.PP
|
|
The commands
|
|
.CW "x T" ,
|
|
.CW "x r " ...,
|
|
and
|
|
.CW "x i"
|
|
must occur first;
|
|
fonts must be mounted before they can be used;
|
|
.CW "x s
|
|
comes last.
|
|
There are no other order requirements.
|
|
.PP
|
|
The following is the output from
|
|
.CW hello, "" ``
|
|
.CW world ''
|
|
for a typical printer,
|
|
as described in §23:
|
|
.P1
|
|
x T utf
|
|
x res 720 1 1
|
|
x init
|
|
V0
|
|
p1
|
|
.P2
|
|
.P1
|
|
x font 1 R
|
|
x font 2 I
|
|
x font 3 B
|
|
x font 4 BI
|
|
x font 5 CW
|
|
x font 6 H
|
|
x font 7 HB
|
|
x font 8 HX
|
|
x font 9 S1
|
|
x font 10 S
|
|
.P2
|
|
.P1
|
|
s10
|
|
f1
|
|
H0
|
|
s10
|
|
f1
|
|
V0
|
|
H720
|
|
V120
|
|
ch
|
|
50e44l28l28o50,w58w72o50r33l28dn120 0
|
|
x trailer
|
|
V7920
|
|
x stop
|
|
.P2
|
|
.PP
|
|
\*(Tr output is normally not redundant;
|
|
size and font changes and position information are not included
|
|
unless needed.
|
|
Nevertheless, each page is self-contained, for the benefit of postprocessors
|
|
that re-order pages or process only a subset.
|
|
.NH
|
|
Device and Font Description Files
|
|
.PP
|
|
The parameters that describe a output device
|
|
.I name
|
|
are read
|
|
from the directory
|
|
.CW /sys/lib/troff/font/dev@name@ ,
|
|
each time
|
|
\*(TR
|
|
is invoked.
|
|
The device name is provided by default,
|
|
by the environment variable
|
|
.CW TYPESETTER ,
|
|
or by a command-line argument
|
|
.CW -T@name@ .
|
|
The default device name is
|
|
.CW utf ,
|
|
for \s-1UTF\s0-encoded Unicode characters.
|
|
The pre-defined string
|
|
.CW .T
|
|
contains the name of the device.
|
|
The
|
|
.CW -F
|
|
command-line option may be used to change the default directory.
|
|
.......
|
|
.sc "Device description file.
|
|
General parameters of the device are stored, one per line, in
|
|
the file
|
|
.CW /sys/lib/troff/font/dev@name@/DESC ,
|
|
as a sequence of names and values.
|
|
\*(Tr recognizes these parameters, and ignores any
|
|
others that may be present for specific drivers:
|
|
.IP
|
|
.nf
|
|
.ta 1i
|
|
@cw fonts ~ n ~ F sub 1 ~F sub 2 ~. . .~ F sub n@
|
|
@cw sizes ~ s sub 1 ~ s sub 2 ~ . . . cw 0@
|
|
@cw res ~n@
|
|
@cw hor ~n@
|
|
@cw vert ~n@
|
|
@cw unitwidth ~n@
|
|
@cw charset@
|
|
\f2list of multi-character character names (optional)\fP
|
|
.LP
|
|
The @F sub i@ are font names
|
|
to be initially mounted.
|
|
The list of sizes is a set of integers representing
|
|
some or all of the legal sizes the device can produce,
|
|
terminated by a zero.
|
|
The
|
|
.CW res
|
|
parameter gives the resolution of the machine in units per inch;
|
|
.CW hor
|
|
and
|
|
.CW ver
|
|
give the minimum number of units that can be moved
|
|
horizontally and vertically.
|
|
.PP
|
|
Character widths for each font are assumed to be given in machine units
|
|
at point size
|
|
.CW unitwidth .
|
|
(In other words, a character with a width of
|
|
@n@ is @n@ units wide at size
|
|
.CW unitwidth .)
|
|
All widths are integers at all sizes.
|
|
.PP
|
|
A list of valid character names may be introduced by
|
|
.CW charset ;
|
|
the list of names is optional.
|
|
.PP
|
|
A line whose first non-blank character is
|
|
.CW #
|
|
is a comment.
|
|
Except that
|
|
.CW charset
|
|
must occur last, parameters may appear in any order.
|
|
.PP
|
|
Here is a subset of the
|
|
.CW DESC
|
|
file for a typical Postscript printer:
|
|
.P1
|
|
# Description file for Postscript printers.
|
|
|
|
fonts 10 R I B BI CW H HB HX S1 S
|
|
sizes 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
|
|
24 25 26 27 28 29 30 31 32 33 34 35 36 38 40 44 48 54 60 72 0
|
|
res 720
|
|
hor 1
|
|
vert 1
|
|
unitwidth 10
|
|
charset
|
|
hy ct fi fl ff Fi Fl dg em 14 34 12 en aa
|
|
ga ru sc dd -> br Sl ps cs cy as os =. ld
|
|
rd le ge pp -+ ob vr
|
|
sq bx ci fa te ** pl mi eq ~= *A *B *X *D
|
|
*E *F *G *Y *I *K *L *M *N *O *P *R *H *S *T *U *W
|
|
*C *Q *Z ul rn *a *b *x *d *e *f *g *y *i *k
|
|
*l *m *n *o *p *h *r *s *t *u *w *c *q *z
|
|
.P2
|
|
.sc "Font description files.
|
|
Each font is described by an analogous description file,
|
|
which begins with parameters of the font, one per line, followed by a
|
|
list of characters and widths.
|
|
The file for font
|
|
.I f
|
|
is
|
|
.CW /sys/lib/troff/font/dev@name@/@f@ .
|
|
.IP
|
|
.ta 1.7i
|
|
.nf
|
|
@cw name ~str@ name of font is @str@
|
|
@cw ligatures ~ ". . ." ~ cw "0"@ list of ligatures
|
|
@cw spacewidth ~n@ width of a space on this font
|
|
@cw special@ this is a special font
|
|
@cw charset@
|
|
\f2list of character name, width, ascender/descender, code\fP, tab separated
|
|
.LP
|
|
The
|
|
.CW name
|
|
and
|
|
.CW charset
|
|
fields are mandatory;
|
|
.CW charset
|
|
must be last.
|
|
Comments are permitted,
|
|
as are other unrecognized parameters.
|
|
.PP
|
|
Each line following
|
|
.CW charset
|
|
describes one character: its name, its width in units as described above,
|
|
ascender/descender information, and a decimal, octal or hexadecimal value
|
|
by which the output device knows it
|
|
(the
|
|
.CW \eN
|
|
``number'' of the character).
|
|
The character name is arbitrary, except that
|
|
.CW ---
|
|
signifies an unnamed character.
|
|
If the width field contains
|
|
.CW \&" ,
|
|
the name is a synonym for the previous character.
|
|
The ascender/descender field is 1 if
|
|
the character has a descender (hangs below the baseline, like
|
|
.CW y ),
|
|
is 2 if it has an ascender (is tall, like
|
|
.CW Y ),
|
|
is 3 if both,
|
|
and is 0 if neither.
|
|
The value is returned
|
|
in the
|
|
.CW ct
|
|
register, as computed by the
|
|
.CW \ew
|
|
function (§11.2).
|
|
.PP
|
|
Here are excerpts from a typical font description file
|
|
for the same Postscript printer.
|
|
.P1
|
|
hy 33 0 45 hyphen \e(hy
|
|
- " - is a synonym for \e(hy
|
|
.sp .3
|
|
Q 72 3 81
|
|
.sp .3
|
|
a 44 0 97
|
|
b 50 2 98
|
|
c 44 0 99
|
|
d 50 2 100
|
|
y 50 1 121
|
|
.sp .3
|
|
em 100 0 208
|
|
--- 44 2 220 Pound symbol £, \eN'220'
|
|
--- 36 0 221 centered dot \eN'221'
|
|
.P2
|
|
This says, for example, that the width of the letter
|
|
.CW a
|
|
is 44 units at point size 10,
|
|
the value of
|
|
.CW unitwidth .
|
|
Point sizes are scaled linearly and rounded, so the width of
|
|
.CW a
|
|
will be 44 at size 10, 40 at size 9, 35 at size 8,
|
|
and so on.
|
|
.sp 100
|
|
.BP
|
|
.fp 8 C CW
|
|
.tr &.
|
|
.tr |
|
|
.tr ~|
|
|
.TL
|
|
Tutorial Examples
|
|
.SP
|
|
....2C
|
|
.sp .25i
|
|
.SH
|
|
Introduction
|
|
.PP
|
|
It is almost always necessary to
|
|
prepare at least a small set of macro definitions
|
|
to describe a document.
|
|
Such common formatting needs
|
|
as page margins and footnotes
|
|
are deliberately not built into \*(NR and \*(TR.
|
|
Instead,
|
|
the macro and string definition, number register, diversion,
|
|
environment switching, page-position trap, and conditional input mechanisms
|
|
provide the basis for user-defined implementations.
|
|
.PP
|
|
For most uses, a standard package like
|
|
.CW -ms
|
|
or
|
|
.CW -mm
|
|
is the right choice.
|
|
The next stage is to augment that,
|
|
or to selectively replace macros from the standard package.
|
|
The last stage, much harder,
|
|
is to write one's own from scratch.
|
|
This is not a task for the novice.
|
|
.PP
|
|
The examples discussed here are intended to be useful and somewhat realistic,
|
|
but will not necessarily cover all relevant contingencies.
|
|
Explicit numerical parameters are used
|
|
in the examples
|
|
to make them easier to read and to
|
|
illustrate typical values.
|
|
In many cases, number registers would be used
|
|
to reduce the number of places where numerical
|
|
information is kept,
|
|
and to concentrate conditional parameter initialization
|
|
like that which depends on whether \*(TR or \*(NR is being used.
|
|
.SH
|
|
Page Margins
|
|
.PP
|
|
As discussed in §3,
|
|
header and footer macros are usually defined
|
|
to describe the top and bottom page margin areas respectively.
|
|
A trap is planted at page position 0 for the header, and at
|
|
\fI-N\fR (\fIN\fR from the page bottom) for the footer.
|
|
The simplest such definitions might be
|
|
.P1 .1i
|
|
&de hd \e"define header
|
|
\&'sp 1i
|
|
&& \e"end definition
|
|
&de fo \e"define footer
|
|
\&'bp
|
|
&& \e"end definition
|
|
&wh 0 hd
|
|
&wh -1i fo
|
|
.P2
|
|
which provide blank 1 inch top and bottom margins.
|
|
The header will occur on the \fIfirst\fR page
|
|
only if the definition and trap exist prior to
|
|
the initial pseudo-page transition (§3).
|
|
In fill mode, the output line that springs the footer trap
|
|
was typically forced out because some part or whole word didn't fit on it.
|
|
If anything in the footer and header that follows causes a break,
|
|
that word or part word will be forced out.
|
|
In this and other examples,
|
|
requests like \&\f(CWbp\fR and \&\f(CWsp\fR that normally cause breaks are invoked using
|
|
the no-break control character \&\f(CW'\fR
|
|
to avoid this.
|
|
When the header/footer design contains material
|
|
requiring independent text processing, the
|
|
environment may be switched, avoiding
|
|
most interaction with the running text.
|
|
.PP
|
|
A more realistic example would be
|
|
.P1 .1i
|
|
&de hd \e"header
|
|
&if \e\en%>1 \e{\e
|
|
\&'sp ~0.5i-1 \e"tl base at 0.5i
|
|
&tl ''- % -'' \e"centered page number
|
|
&ps \e"restore size
|
|
&ft \e"restore font
|
|
&vs \e} \e"restore vs
|
|
\&'sp ~1.0i \e"space to 1.0i
|
|
&ns \e"turn on no-space mode
|
|
&&
|
|
&de fo \e"footer
|
|
&ps 10 \e"set footer/header size
|
|
&ft R \e"set font
|
|
&vs 12p \e"set baseline spacing
|
|
&if \e\en%=1 \e{\e
|
|
\&'sp ~\e\en(.pu-0.5i-1 \e"tl base 0.5i up
|
|
&tl ''- % -'' \e} \e"first page number
|
|
\&'bp
|
|
&&
|
|
&wh 0 hd
|
|
&wh -1i fo
|
|
.P2
|
|
which sets the size, font, and baseline spacing for the
|
|
header/footer material, and ultimately restores them.
|
|
The material in this case is a page number at the bottom of the
|
|
first page and at the top of the remaining pages.
|
|
The \&\f(CWsp\fR's refer to absolute positions to avoid
|
|
dependence on the baseline spacing.
|
|
Another reason for doing this in the footer
|
|
is that the footer is invoked by printing a line whose
|
|
vertical spacing swept past the trap position by possibly
|
|
as much as the baseline spacing.
|
|
No-space mode is turned on at the end of \&\f(CWhd\fR
|
|
to render ineffective
|
|
accidental occurrences of \&\f(CWsp\fR at the top of the running text.
|
|
.PP
|
|
This method of restoring size, font, etc., presupposes
|
|
that such requests (that set \fIprevious\fR value) are \fInot\fR
|
|
used in the running text.
|
|
A better scheme is to save and restore both the current \fIand\fR
|
|
previous values as shown for size in the following:
|
|
.P1 .1i
|
|
&de fo
|
|
&nr s1 \e\en(.s \e"current size
|
|
&ps
|
|
&nr s2 \e\en(.s \e"previous size
|
|
& --- \e"rest of footer
|
|
&&
|
|
&de hd
|
|
& --- \e"header stuff
|
|
&ps \e\en(s2 \e"restore previous size
|
|
&ps \e\en(s1 \e"restore current size
|
|
&&
|
|
.P2
|
|
Page numbers may be printed in the bottom margin
|
|
by a separate macro triggered during the footer's
|
|
page ejection:
|
|
.P1 .1i
|
|
&de bn \e"bottom number
|
|
&tl ''- % -'' \e"centered page number
|
|
&&
|
|
&wh -0.5i-1v bn \e"tl base 0.5i up
|
|
.P2
|
|
.SH
|
|
Paragraphs and Headings
|
|
.PP
|
|
The housekeeping
|
|
associated with starting a new paragraph should be collected
|
|
in a paragraph macro
|
|
that, for example,
|
|
does the desired preparagraph spacing,
|
|
forces the correct font, size, baseline spacing, and indent,
|
|
checks that enough space remains for \fImore than one\fR line,
|
|
and
|
|
requests a temporary indent.
|
|
.P1 .1i
|
|
&de pg \e"paragraph
|
|
&br \e"break
|
|
&ft R \e"force font,
|
|
&ps 10 \e"size,
|
|
&vs 12p \e"spacing,
|
|
&in 0 \e"and indent
|
|
&sp 0.4 \e"prespace
|
|
&ne 1+\e\en(.Vu \e"want more than 1 line
|
|
&ti 0.2i \e"temp indent
|
|
&&
|
|
.P2
|
|
The first break in \&\f(CWpg\fR
|
|
will force out any previous partial lines,
|
|
and must occur before the \&\f(CWvs\fR.
|
|
The forcing of font, etc., is
|
|
partly a defense against prior error and
|
|
partly to permit
|
|
things like section heading macros to
|
|
set parameters only once.
|
|
The prespacing parameter is suitable for \*(TR;
|
|
a larger space, at least as big as the output device vertical resolution, would be
|
|
more suitable in \*(NR.
|
|
The choice of remaining space to test for in the \&\f(CWne\fR
|
|
is the smallest amount greater than one line
|
|
(the \&\f(CW.V\fR is the available vertical resolution).
|
|
.PP
|
|
A macro to automatically number section headings
|
|
might look like:
|
|
.P1 .1i
|
|
&de sc \e"section
|
|
& --- \e"force font, etc.
|
|
&sp 0.4 \e"prespace
|
|
&ne 2.4+\e\en(.Vu \e"want 2.4+ lines
|
|
.lg 0
|
|
&fi
|
|
.lg
|
|
\e\en+S.
|
|
&&
|
|
&nr S 0 1 \e"init S
|
|
.P2
|
|
The usage is \&\f(CW.sc\fR,
|
|
followed by the section heading text,
|
|
followed by \&\f(CW.pg\fR.
|
|
The \&\f(CWne\fR test value includes one line of heading,
|
|
0.4 line in the following \&\f(CWpg\fR, and
|
|
one line of the paragraph text.
|
|
A word consisting of the next section number and a period is
|
|
produced to begin the heading line.
|
|
The format of the number may be set by \&\f(CWaf\fR (§8).
|
|
.PP
|
|
Another common form is the labeled, indented paragraph,
|
|
where the label protrudes left into the indent space.
|
|
.P1 .1i
|
|
&de lp \e"labeled paragraph
|
|
&pg
|
|
&in 0.5i \e"paragraph indent
|
|
&ta 0.2i 0.5i \e"label, paragraph
|
|
&ti 0
|
|
\et\e\e$1\et\ec \e"flow into paragraph
|
|
&&
|
|
.P2
|
|
The intended usage is ``\&\f(CW.lp\fR \fIlabel\fR\|'';
|
|
\fIlabel\fR will begin at 0.2 inch, and
|
|
cannot exceed a length of 0.3 inch without intruding into
|
|
the paragraph.
|
|
The label could be right adjusted against 0.4 inch by
|
|
setting the tabs instead with \&\f(CW.ta|0.4iR|0.5i\fR.
|
|
The last line of \&\f(CWlp\fR ends with \&\f(CW\ec\fR so that
|
|
it will become a part of the first line of the text
|
|
that follows.
|
|
.SH
|
|
Multiple Column Output
|
|
.PP
|
|
The production of multiple column pages requires
|
|
the footer macro to decide whether it was
|
|
invoked by other than the last column,
|
|
so that it will begin a new column rather than
|
|
produce the bottom margin.
|
|
The header can initialize a column register that
|
|
the footer will increment and test.
|
|
The following is arranged for two columns, but
|
|
is easily modified for more.
|
|
.P1 .1i
|
|
&de hd \e"header
|
|
& ---
|
|
&nr cl 0 1 \e"init column count
|
|
&mk \e"mark top of text
|
|
&&
|
|
.P2
|
|
.P1 .1i
|
|
&de fo \e"footer
|
|
&ie \e\en+(cl<2 \e{\e
|
|
&po +3.4i \e"next column; 3.1+0.3
|
|
&rt \e"back to mark
|
|
&ns \e} \e"no-space mode
|
|
&el \e{\e
|
|
&po \e\enMu \e"restore left margin
|
|
& ---
|
|
\&'bp \e}
|
|
&&
|
|
&ll 3.1i \e"column width
|
|
&nr M \e\en(.o \e"save left margin
|
|
.P2
|
|
Typically a portion of the top of the first page
|
|
contains full width text;
|
|
the request for the narrower line length,
|
|
as well as another \&\f(CW.mk\fR would
|
|
be made where the two column output was to begin.
|
|
.SH
|
|
Footnotes
|
|
.PP
|
|
The footnote mechanism to be described is used by
|
|
embedding the footnotes in the input text at the
|
|
point of reference,
|
|
demarcated by an initial \&\f(CW.fn\fR and a terminal \&\f(CW.ef\fR:
|
|
.P1 .1i
|
|
&fn
|
|
\fIFootnote text and control lines...\fP
|
|
&ef
|
|
.P2
|
|
In the following,
|
|
footnotes are processed in a separate environment and diverted
|
|
for later printing in the space immediately prior to the bottom
|
|
margin.
|
|
There is provision for the case where the last collected
|
|
footnote doesn't completely fit in the available space.
|
|
.P1 .1i
|
|
&de hd \e"header
|
|
& ---
|
|
&nr x 0 1 \e"init footnote count
|
|
&nr y 0-\e\enb \e"current footer place
|
|
&ch fo -\e\enbu \e"reset footer trap
|
|
&if \e\en(dn .fz \e"leftover footnote
|
|
&&
|
|
.P2
|
|
.P1 .1i
|
|
&de fo \e"footer
|
|
&nr dn 0 \e"zero last diversion size
|
|
&if \e\enx \e{\e
|
|
&ev 1 \e"expand footnotes in ev1
|
|
&nf \e"retain vertical size
|
|
&FN \e"footnotes
|
|
&rm FN \e"delete it
|
|
.P2
|
|
.P1 .1i
|
|
&if "\e\en(.z"fy" .di \e"end overflow di
|
|
&nr x 0 \e"disable fx
|
|
&ev \e} \e"pop environment
|
|
& ---
|
|
\&'bp
|
|
&&
|
|
.P2
|
|
.P1 .1i
|
|
&de fx \e"process footnote overflow
|
|
&if \e\enx .di fy \e"divert overflow
|
|
&&
|
|
.P2
|
|
.P1 .1i
|
|
&de fn \e"start footnote
|
|
&da FN \e"divert (append) footnote
|
|
&ev 1 \e"in environment 1
|
|
&if \e\en+x=1 .fs \e"if 1st, separator
|
|
&fi \e"fill mode
|
|
&&
|
|
.P2
|
|
.P1 .1i
|
|
&de ef \e"end footnote
|
|
&br \e"finish output
|
|
&nr z \e\en(.v \e"save spacing
|
|
&ev \e"pop ev
|
|
&di \e"end diversion
|
|
&nr y -\e\en(dn \e"new footer position,
|
|
&if \e\enx=1 .nr y -(\e\en(.v-\e\enz) \e
|
|
\e"uncertainty correction
|
|
&ch fo \e\enyu \e"y is negative
|
|
&if (\e\en(nl+1v)>(\e\en(.p+\e\eny) \e
|
|
&ch fo \e\en(nlu+1v \e"didn't fit
|
|
&&
|
|
.P2
|
|
.P1 .1i
|
|
&de fs \e"separator
|
|
\el'1i' \e"1 inch rule
|
|
&br
|
|
&&
|
|
.P2
|
|
.P1 .1i
|
|
&de fz \e"get leftover footnote
|
|
&fn
|
|
&nf \e"retain vertical size
|
|
&fy \e"where fx put it
|
|
&ef
|
|
&&
|
|
.P2
|
|
.P1 .1i
|
|
&nr b 1.0i \e"bottom margin size
|
|
&wh 0 hd \e"header trap
|
|
&wh 12i fo \e"footer trap->temp pos
|
|
&wh -\e\enbu fx \e"fx at footer position
|
|
&ch fo -\e\enbu \e"conceal fx with fo
|
|
.P2
|
|
.PP
|
|
The header \&\f(CWhd\fR initializes a footnote count register \&\f(CWx\fR,
|
|
and sets both the current footer trap position register \&\f(CWy\fR and
|
|
the footer trap itself to a nominal position specified in
|
|
register \&\f(CWb\fR.
|
|
In addition, if the register \&\f(CWdn\fR indicates a leftover footnote,
|
|
\&\f(CWfz\fR is invoked to reprocess it.
|
|
The footnote start macro \&\f(CWfn\fR begins a diversion (append) in environment 1,
|
|
and increments the count \&\f(CWx\fR; if the count is one, the footnote separator \&\f(CWfs\fR
|
|
is interpolated.
|
|
The separator is kept in a separate macro to permit user redefinition.
|
|
.PP
|
|
The footnote end macro \&\f(CWef\fR restores
|
|
the previous environment and ends the diversion after saving the spacing size in register \&\f(CWz\fR.
|
|
\&\f(CWy\fR is then decremented by the size of the footnote, available in \&\f(CWdn\fR;
|
|
then on the first footnote, \&\f(CWy\fR is further decremented by the difference
|
|
in vertical baseline spacings of the two environments, to
|
|
prevent the late triggering of the footer trap from causing the last
|
|
line of the combined footnotes to overflow.
|
|
The footer trap is then set to the lower (on the page) of \&\f(CWy\fR or the current page position (\&\f(CWnl\fR)
|
|
plus one line, to allow for printing the reference line.
|
|
.PP
|
|
If indicated by \&\f(CWx\fR, the footer \&\f(CWfo\fR rereads the footnotes from \&\f(CWFN\fR in nofill mode
|
|
in environment 1,
|
|
and deletes \&\f(CWFN\fR.
|
|
If the footnotes were too large to fit, the macro \&\f(CWfx\fR will be trap-invoked to redivert
|
|
the overflow into \&\f(CWfy\fR,
|
|
and the register \&\f(CWdn\fR will later indicate to the header whether \&\f(CWfy\fR is empty.
|
|
.PP
|
|
Both \&\f(CWfo\fR and \&\f(CWfx\fR are planted in the nominal footer trap position in an order
|
|
that causes \&\f(CWfx\fR to be concealed unless the \&\f(CWfo\fR trap is moved.
|
|
The footer then terminates the overflow diversion, if necessary, and
|
|
zeros \&\f(CWx\fR to disable \&\f(CWfx\fR,
|
|
because the uncertainty correction
|
|
together with a not-too-late triggering of the footer can result
|
|
in the footnote rereading finishing before reaching the \&\f(CWfx\fR trap.
|
|
.PP
|
|
A good exercise for the student is to combine the multiple-column and footnote mechanisms.
|
|
.SH
|
|
The Last Page
|
|
.PP
|
|
After the last input file has ended, \*(NR and \*(TR
|
|
invoke the \fIend macro\fR (§7), if any,
|
|
and when it finishes, eject the remainder of the page.
|
|
During the eject, any traps encountered are processed normally.
|
|
At the end of this last page, processing terminates
|
|
unless a partial line, word, or partial word remains.
|
|
If it is desired that another page be started, the end-macro
|
|
.P1 .1i
|
|
&de en \e"end-macro
|
|
\ec
|
|
\&'bp
|
|
&&
|
|
&em en
|
|
.P2
|
|
will deposit a null partial word,
|
|
and produce another last page.
|
|
....1C
|
|
.sp 100
|
|
.BP
|
|
........
|
|
.TL
|
|
Special Character Names
|
|
.SP
|
|
.PP
|
|
The following table lists names for a set of characters,
|
|
most of which have traditionally been provided by \*(TR using
|
|
the `special' or `symbol' font.
|
|
Many of these sequences are old ways to get what are now Unicode
|
|
characters;
|
|
Lucida Sans, for example, has glyphs corresponding to many of these
|
|
but does not have the special sequences.
|
|
Therefore
|
|
the \*(TR sequence
|
|
.CW \e(*F
|
|
gives the character \(*F from the Times font instead of the
|
|
character Φ from the current font, in this case Lucida Sans.
|
|
Not all sequences print on any particular device, including this one; Peter
|
|
faces appear in their place.
|
|
.TS
|
|
center;
|
|
l l20fCW l l20fCW l l20fCW.
|
|
\&\' \e' \(*m \e(*m \(~= \e(~=
|
|
\` \e` \(*n \e(*n \(ap \e(ap
|
|
\(em \e(em \(*c \e(*c \(!= \e(!=
|
|
\(en \e(en \(*o \e(*o \(-> \e(->
|
|
\(hy \e(hy \(*p \e(*p \(<- \e(<-
|
|
\- \e- \(*r \e(*r \(ua \e(ua
|
|
\(bu \e(bu \(*s \e(*s \(da \e(da
|
|
\(sq \e(sq \(ts \e(ts \(mu \e(mu
|
|
\(ru \e(ru \(*t \e(*t \(di \e(di
|
|
\(14 \e(14 \(*u \e(*u \(+- \e(+-
|
|
\(12 \e(12 \(*f \e(*f \(cu \e(cu
|
|
\(34 \e(34 \(*x \e(*x \(ca \e(ca
|
|
\(fi \e(fi \(*q \e(*q \(sb \e(sb
|
|
\(fl \e(fl \(*w \e(*w \(sp \e(sp
|
|
\(ff \e(ff \(*A \e(*A \(ib \e(ib
|
|
\(Fi \e(Fi \(*B \e(*B \(ip \e(ip
|
|
\(Fl \e(Fl \(*G \e(*G \(if \e(if
|
|
\(de \e(de \(*D \e(*D \(pd \e(pd
|
|
\(dg \e(dg \(*E \e(*E \(gr \e(gr
|
|
\(fm \e(fm \(*Z \e(*Z \(no \e(no
|
|
\(ct \e(ct \(*Y \e(*Y \(is \e(is
|
|
\(rg \e(rg \(*H \e(*H \(pt \e(pt
|
|
\(co \e(co \(*I \e(*I \(es \e(es
|
|
\(pl \e(pl \(*K \e(*K \(mo \e(mo
|
|
\(mi \e(mi \(*L \e(*L \(br \e(br
|
|
\(eq \e(eq \(*M \e(*M \(dd \e(dd
|
|
\(** \e(** \(*N \e(*N \(rh \e(rh
|
|
\(sc \e(sc \(*C \e(*C \(lh \e(lh
|
|
\(aa \e(aa \(*O \e(*O \(L1 \e(bs
|
|
\(ga \e(ga \(*P \e(*P \(or \e(or
|
|
\(ul \e(ul \(*R \e(*R \(ci \e(ci
|
|
\(sl \e(sl \(*S \e(*S \(lt \e(lt
|
|
\(*a \e(*a \(*T \e(*T \(lb \e(lb
|
|
\(*b \e(*b \(*U \e(*U \(rt \e(rt
|
|
\(*g \e(*g \(*F \e(*F \(rb \e(rb
|
|
\(*d \e(*d \(*X \e(*X \(lk \e(lk
|
|
\(*e \e(*e \(*Q \e(*Q \(rk \e(rk
|
|
\(*z \e(*z \(*W \e(*W \(bv \e(bv
|
|
\(*y \e(*y \(sr \e(sr \(lf \e(lf
|
|
\(*h \e(*h \(rn \e(rn \(rf \e(rf
|
|
\(*i \e(*i \(>= \e(>= \(lc \e(lc
|
|
\(*k \e(*k \(<= \e(<= \(rc \e(rc
|
|
\(*l \e(*l \(== \e(== \d\h'-5m'\(LH\u \e(LH
|
|
.TE
|