- Fail if no parameter is provided.
- The "CALL :label args..." syntax is available only when command extensions
are enabled. Fail if this syntax is used outside of a batch context.
- Reparse the CALL command parameter with the command parser, in order
to accurately parse and interpret it as a possible command (including
escape carets, etc...) and not duplicate the logic.
** CURRENT Windows' CMD-compatibility LIMITATION ** (may be lifted in
a "ROS-specific" running mode of CMD): only allow standard commands to
be specified as parameter of the CALL command.
This reparsing behaviour can be observed in Windows' CMD, by dumping
the interpreted commands after enabling the cmd!fDumpParse flag from
a debugger (using public symbols).
- When reparsing, we should tell the parser to NOT ignore lines that
start with a colon, because in this situation these are to be
considered as valid "commands" (for parsing "CALL :label").
* For Windows' CMD-compatibility, the remaining escape carets need to
be doubled again so that, after the new parser step, they are escaped
back to their original form. But then we also need to do it the "buggy"
way à la Windows, where carets in quotes are doubled either! However
when being re-parsed, since they are in quotes they remain doubled!!
(see "Phase 6" in https://stackoverflow.com/a/4095133/13530036 ).
* A MSCMD_CALL_QUIRKS define allows to disable this buggy behaviour,
and instead tell the parser to not not interpret the escape carets.
- When initializing a new batch context when the "CALL :label" syntax is
used, ensure that we reuse the same batch file position pointer as its
parent, so as to have correct call label ordering behaviour.
That is,
:label
ECHO hi
CALL :label
:label
ECHO bye
should display:
hi
bye
bye
i.e., the CALL calls the second label instead of the first one (and
thus entering into an infinite loop).
Finally, the "CALL :label" syntax strips the first ':' away, so, as a
side-effect, the command "CALL :EOF" fails (otherwise it would perform
a "GOTO :EOF" and succeeds), while "CALL ::EOF" succeeds.
Fixes some cmd_winetests.
All these modifications have been verified with Windows' CMD, either
by using written cmd_rostests and the existing cmd_winetests, or
manually by enabling the flags cmd!fDumpTokens and cmd!fDumpParse
(available in the public symbols) and analyzing how the tokens are
being parsed, as well as the generated command tree.
See also the following links for more details (but remember that these
observations have to be double-checked in Windows' CMD!):
* Parser rules: https://stackoverflow.com/a/4095133/13530036
* Discussion: https://www.dostips.com/forum/viewtopic.php?f=3&t=8355
* Numbers parsing: https://www.dostips.com/forum/viewtopic.php?t=3758
* Label names vs. GOTO and CALL: https://www.dostips.com/forum/viewtopic.php?f=3&t=3803
and: https://www.dostips.com/forum/viewtopic.php?f=3&t=3803&p=55405#p55405
- Fix REM command parsing. A C_COMMAND-like structure should still
be built, so that it can show up during batch command echo. However
some specific handling needs to be done, so use instead a new C_REM
command type.
Escape carets are parsed differently than usual: they are explicitly
kept in the command line and don't participate in line continuations.
Also, the Windows' CMD behaviour is to discards everything before the
last line continuation.
- Prefix operator '@' (the "silent" operator) is parsed as a separate
command. Thus, the command @@foo@bar is parsed as: '@', '@', 'foo@bar'.
- Improve the checks for numbered redirection.
For this purpose, we check whether this is a number, that is in first
position in the current parsing buffer or is preceded by a whitespace-
like separator, including standard command operators (excepting '@' !)
and double-quotes.
- Empty command blocks, i.e. "( )", standing by themselves, or present
in IF or FOR commands, are considered invalid. (The closing parenthesis
is considered "unexpected".)
- Ignore single closing parenthesis when being outside of command blocks,
thus interpreting it as a command, and ignore explicitly everything
following on the same line, including line continuations.
This very specific situation can happen e.g. while running in batch mode,
when jumping to a label present inside a command block.
See the code for a thorough explanation.
- Detect whether a parenthesized block is not terminated at the end
of a command stream (getting a NUL character instead of a newline),
and if so, bail out early instead of entering into an infinite loop.
- Perform a similar check for the parenthesized list in FOR commands.
- Initialize the static 'InsideBlock' value to a known value.
- The '&' operator (multi-commmand) is allowed to have an empty RHS.
When such situation occurs, turn the CurrentTokenType to TOK_END
so as to avoid a parse error later on.
- The main body of a IF statement, or its 'else' clause, as well as
the main body of a FOR statement, must not be empty, otherwise this
is considered a syntax error. If so, call ParseError() that sets
the 'bParseError' flag, and forcing all batch execution to stop.
CORE-13682
- Split SubstituteVars() into its main loop and a helper SubstituteVar()
that just substitutes only one variable.
- Use this new helper as the basis of the proper implementation of the
delayed expansion of variables.
- Fix a bug introduced in commit 495c82cc, when GetBatchVar() fails.
CORE-11857 CORE-13736
It will be followed with a separate fix for the FOR-loop code.
Fixes some cmd_winetests.
A NULL pointer can be returned for a valid existing batch/FOR variable,
in which case the enhanced-variable getter should return an empty string.
This situation can happen e.g. when forcing a FOR-loop to tokenize a
text line with not enough tokens in it.
- Display the names of the files being TYPEd only if more than one file
has been specified on the command-line, or if a file specification
(with wildcards) is present (even just for one).
These names are displayed on STDERR while the files are TYPEd on
STDOUT, therefore allowing concatenating files by just redirecting
STDOUT to a destination, without corrupting it with the displayed file
names. Also, add a /N option to force not displaying these file names.
- When file specifications (with wildcards) are being processed, silently
ignore any directories matching them. If no corresponding files have
been found, display a file-not-found error.
- When explicitly directory names are specified, don't do any special
treatment; the CreateFile() call will fail and return the appropriate
error.
- Fix the returned errorlevel values.
See https://ss64.com/nt/type.html for more information.
Fixes some cmd_winetests.
- When reading from a file, retrieve its original size so that
we can stop reading it once we are beyond its original ending.
This allows avoiding an infinite read loop in case the output of
the file is redirected back to it.
Fixes CORE-17208
- Move the FileGetString() helper to the only file where it is
actually used.
This functionality is: case insensitivity comparisons (/I);
CMDEXTVERSION and DEFINED unary operators; EQU, NEQ, LSS, LEQ, GTR, GEQ
generic string comparators.
We note two things, when CMD searches for the corresponding label in the
batch file:
- the first character of the line is always ignored, unless it's a colon;
- the escape caret ^ is supported and interpreted.
Fixes some cmd_winetests.
CORE-13713 CORE-13736
- In case execution of all batch contexts is stopped (by selecting "All"
at the Ctrl-C/Ctrl-Break prompt), notify as well the CheckCtrlBreak()
signal handler once there are no more batch contexts (this in effect
resets the internal 'bLeaveAll' static flag in CheckCtrlBreak).
This is an adaptation of the fix present in FreeCOM 1.5, first
described in https://gcfl.net/FreeDOS/command.com/bugs074g.html .
- Introduce a ParseErrorEx() helper that sets the 'bParseError' flag and
displays a customized syntax-error message, only for the first syntax
error encountered. Implement ParseError() around the *Ex function.
- In batch mode, echo the original pre-parsed batch file line if a parse
error has been encountered.
- When running a compound command - including IF, FOR, command blocks -,
and that control flow is modified by any CALL/GOTO/EXIT command,
detect this while running the compound command so as to stop it and go
back to the main batch execution loop, that will then set up the actual
new command to run.
- In GOTO, do not process any more parts of a compound command only when
we have found a valid label.
This allows to break commands such as:
C:\ReactOS\system32> for %f in (*.*) do dir
as one would expect: stop the currently running 'dir' and the 'for'.
"bCtrlBreak" doesn't need to be volatile too.
Using CTRL-C to cancel command line input would leave the prompt in
a state where the next command would be ignored. For example:
dir<CTRL-C>
dir
would cause cmd.exe to ignore the second dir command.
