Eli Zaretskii wrote:
> > There are different ways to test for "executable" on Windows:
> > - execlp/execvp,
> > - CreateProcess,
> > - system / popen, like you say,
> > - cmd.exe,
> > - surely more (PowerShell...)
> >
> > Let's assume that they work differently (cmd.exe definitely works
> > differently
> > than execlp/execvp; I tested that).
> >
> > The module does not attempt to handle all of these, just the first one,
> > because
> > - the function access() is located at the C library level,
> > - it is compatible with what the old MSVCRT (without the argument check
> > for the mode in _access()) does.
>
> Well, at the very least how about documenting this subtlety?
Done as follows:
2019-09-28 Bruno Haible <br...@clisp.org>
access: Document limitations on Windows.
Suggested by Zaretskii <e...@gnu.org>.
* doc/posix-functions/access.texi: Mention two limitations on Windows.
diff --git a/doc/posix-functions/access.texi b/doc/posix-functions/access.texi
index 49064d2..8bfa2c1 100644
--- a/doc/posix-functions/access.texi
+++ b/doc/posix-functions/access.texi
@@ -31,4 +31,17 @@ this function, especially in a set-uid or set-gid program.
This function does not have an option for not following symbolic links
(like @code{stat} versus @code{lstat}). If you need this option, use
the Gnulib module @code{faccessat} with the @code{AT_EACCESS} flag.
+@item
+On native Windows, files whose basename does not contain a @samp{.}
+cannot be executed through @code{execlp} or @code{execvp}. Nevertheless,
+this function may return true for such files.
+@item
+On Windows, different facilities for executing a program have different
+ways of finding an executable file, by trying various suffixes. For
+example, @code{execlp} and @code{execvp} search for files with the
+suffixes @code{.com}, @code{.exe}, @code{.bat}, @code{.cmd}, when the
+file with the given file name does not exist. Whereas @code{cmd.exe}
+searches according to the @code{PATHEXT} environment variable. This
+function does not perform any search; it merely looks at the file with
+the given file name.
@end itemize
