reactos/posix/apps/posixw32/readme.txt

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$Id: readme.txt,v 1.1 2002/06/09 08:37:07 ea Exp $
posixw32 - a Win32 client terminal emulator for the POSIX+ subsystem
SYNOPSYS
posixw32 [program]
program program to be run in the terminal; if none is given,
the shell for the current user (W32 session's) is
used.
DESCRIPTION
posixw32 emulates a DEC VT-100 terminal (on top of the CSRSS
subsystem, hence the name) which is the controlling terminal
for a process [program] running in the context of the PSX
subsystem. posixw32 is a Win32 console application, not a PSX
application. The process created by the PSX subsystem on behalf
of posixw32 is not the child of the posixw32 instance that
requested it. posixw32 simply performs terminal I/O in the CSRSS
world (the W32 world!) for [program].
NOTES
The role of posixw32 is creating a session in the PSX subsystem
managing any I/O for it. This is how it works:
1. posixw32 creates two well known named objects in the system
name space that will allow the PSX subsystem server to build
the I/O channel for the session. To let the PSX subsystem
process recognize the objects, they contain a numeric suffix
which is the process identifier (n) the system gives to each
instance of posixw32:
\POSIX+\Session\Pn LPC port (IPC rendez-vous object)
\POSIX+\Session\Dn section (shared memory object)
posixw32 also creates a new thread to manage the calls though
the LPC port. Port Pn is used by the subsystem to control the
terminal which posixw32 emulates.
2. posixw32 connects to the PSX subsystem session port
\POSIX+\SessionPort
and asks the subsystem to create a new session.
3. The PSX subsystem, if it decides to accept the request, creates
a new session for that calling instance of posixw32 (n), and in
turn connects back to the terminal control port
\POSIX+\Session\Pn
4. When posixw32 makes the PSX subsystem create the new session, it
also tells the subsystem what program should be the session
leader process. The PSX subsystem creates that process (the
image file to start must be marked IMAGE_SUBSYSTEM_POSIX_GUI or
IMAGE_SUBSYSTEM_POSIX_CUI).
5. The requested process [program] runs in the context of the
PSX subsystem and performs any terminal I/O via the channel
posixw32 and the PSX susbstem created.
REVISIONS
2001-05-05 created
2002-03-03 simplified
2002-06-08 renamed to avoid future name clash
AUTHOR
Emanuele Aliberti <ea@iol.it>
CREDITS
John L. Miller (johnmil@cs.cmu.edu, johnmil@jprc.com) code for
a basic VT-100 emulator for Win32 consoles is used to process
tc* calls output.
EOF