On 2022-01-13 10:07, Kaz Kylheku (Cygwin) wrote:
On 2022-01-13 05:40, Eliot Moss wrote:
On 1/13/2022 1:39 AM, Jay K wrote:
ExitProcess does not work in Cygwin?
Just use POSIX exit(3)!
ExitProcess does not appear to be a POSIX function.
This is a real issue worth looking into. Though ExitProcess isn't a POSIX
function, Cygwin can capture the termination status of non-Cygwin programs.
The concept of termination status cannot be entirely walled off in a
private Cygwin garden; it belongs to the underlying platform.
In Cygwin, I can do this:
C:\Cygwin\cygwin64\home\kaz>exit 1
1:BLACKBOX:~$
1:BLACKBOX:~$ echo $?
1
0:BLACKBOX:~$ cmd
Microsoft Windows [Version 10.0.19042.1052]
(c) Microsoft Corporation. All rights reserved.
C:\Cygwin\cygwin64\home\kaz>exit 0
0:BLACKBOX:~$
The number in my Bash prompt is the last exit code. As you can see,
the non-Cygwin CMD.EXE program produces a termination code which
is recognized in the Cygwin world.
Most likely it does that via ExitProcess.
It is odd if calling ExitProcess in a Cygwin process causes
a Cygwin parent not to similarly process the status, as seems
to be shown by Jay's test cases.
Cygwin supports non-POSIX programming; you can write GUI applications
using Win32 calls for instance.
(Now I agree that for exiting your process, even if it's a GUI
application using numerous win32 calls, you should probably do it the
Cygwin way, and use exit, or return from main. But still ...)
Cygwin installs at-exit handlers and it is likely that when these have
finished, they return a Cygwin exit status if passed by the POSIX
function, perhaps unless some error has occurred during at-exit handling.
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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