Eli Zaretskii wrote in
<https://lists.gnu.org/archive/html/bug-grep/2014-05/msg00118.html>:

  ... found that the implementation of the exec* family did
  the following: it started the process that runs the child program, and
  then immediately exited without waiting for the child to finish.
  ...
  The solution was to reimplement execvp in a way that didn't exit ...
  until the child program finished.

Indeed, that is a major problem with these exec* implementations: The
parent process cannot know the exit code if the exec'd process runs
asynchronously.

Another major problem is that the Windows _spawnv* and CreateProcess
functions split the arguments when they contain spaces or special
characters.

All of these problems are fixed with these new Gnulib modules.


2020-12-26  Bruno Haible  <bruno@clisp.org>

	execlp: Add tests.
	* tests/test-execlp-main.c: New file.
	* tests/test-execlp.sh: New file.
	* modules/execlp-tests: New file.

	execlp: New module.
	* lib/execlp.c: New file.
	* m4/execlp.m4: New file.
	* modules/execlp: New file.
	* doc/posix-functions/execlp.texi: Mention more Windows problems and the
	new module.

	execle: Add tests.
	* tests/test-execle-main.c: New file.
	* tests/test-execle.sh: New file.
	* modules/execle-tests: New file.

	execle: New module.
	* lib/execle.c: New file.
	* m4/execle.m4: New file.
	* modules/execle: New file.
	* doc/posix-functions/execle.texi: Mention more Windows problems and the
	new module.

	execl: Add tests.
	* tests/test-execl-main.c: New file.
	* tests/test-execl.sh: New file.
	* modules/execl-tests: New file.

	execl: New module.
	* lib/execl.c: New file.
	* m4/execl.m4: New file.
	* modules/execl: New file.
	* doc/posix-functions/execl.texi: Mention more Windows problems and the
	new module.

	execv: Add tests.
	* tests/test-execv-main.c: New file.
	* tests/test-execv.sh: New file.
	* modules/execv-tests: New file.

	execv: New module.
	* lib/execv.c: New file.
	* m4/execv.m4: New file.
	* modules/execv: New file.
	* doc/posix-functions/execv.texi: Mention more Windows problems and the
	new module.

	execvp: Add tests.
	* tests/test-execvp-main.c: New file.
	* tests/test-execvp.sh: New file.
	* modules/execvp-tests: New file.

	execvp: New module.
	* lib/execvp.c: New file.
	* m4/execvp.m4: New file.
	* modules/execvp: New file.
	* doc/posix-functions/execvp.texi: Mention more Windows problems and the
	new module.

	execvpe: Add tests.
	* tests/test-execvpe-main.c: New file.
	* tests/test-execvpe.sh: New file.
	* modules/execvpe-tests: New file.

	execvpe: New module.
	* lib/execvpe.c: New file.
	* m4/execvpe.m4: New file.
	* modules/execvpe: New file.
	* doc/glibc-functions/execvpe.texi: Mention the Windows problems and the
	new module.

	execve: Add tests.
	* tests/test-exec-child.c: New file.
	* tests/test-execve-main.c: New file.
	* tests/test-execve.sh: New file.
	* modules/execve-tests: New file.

	execve: New module.
	* lib/execve.c: New file.
	* m4/execve.m4: New file.
	* modules/execve: New file.
	* doc/posix-functions/execve.texi: Mention more Windows problems and the
	new module.

	execve, execvpe, execvp, execv, execl, execle, execlp: Prepare modules.
	* lib/unistd.in.h (execl, execle, execlp, execv, execve, execvp,
	execvpe): Add declarations for the new modules.
	* m4/unistd_h.m4 (gl_UNISTD_H): Test whether execl, execle, execlp,
	execv, execve, execvp, execvpe are declared.
	(gl_UNISTD_H_DEFAULTS): Initialize GNULIB_EXEC*, HAVE_EXECVPE,
	REPLACE_EXEC*.
	* modules/unistd (Makefile.am): Substitute GNULIB_EXEC*, HAVE_EXECVPE,
	REPLACE_EXEC*.
	* tests/test-unistd-c++.cc: Check the signature of execl, execle,
	execlp, execv, execve, execvp, execvpe.