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<title>
Autoconf Macro: acx_func_fork
</title>
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<a href="http://autoconf-archive.cryp.to/acx_func_fork.m4">Download M4
Source</a>
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<hr>
<h1>
acx_func_fork
</h1>
<h2>
Synopsis
</h2>
<p class="indent" style="white-space:nowrap;">
<code>ACX_FUNC_FORK</code>
</p>
<h2>
Description
</h2>
<div class="indent">
<p>
Check to for a working fork. Use to provide a workaround for systems that
don't have a working fork. For example, the workaround for the
fork()/exec() sequence for DOS is to use spawn.
</p>
<p>
Defines HAVE_NO_FORK is fork() doesn't work or isn't implemented.
</p>
</div>
<h2>
Author
</h2>
<p class="indent">
Mark Elbrecht <snowball3@bigfoot.com>
</p>
<h2>
Last Modified
</h2>
<p class="indent">
2000-07-19
</p>
<h2>
M4 Source Code
</h2>
<div class="indent">
<pre class="m4source">
AC_DEFUN([ACX_FUNC_FORK],
[AC_MSG_CHECKING(for a working fork)
AC_CACHE_VAL(acx_cv_func_fork_works,
[AC_REQUIRE([AC_TYPE_PID_T])
AC_REQUIRE([AC_HEADER_SYS_WAIT])
AC_TRY_RUN([#include <sys/types.h>
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
int main()
{
int status;
pid_t child = fork();
if (child < 0) /* Error */
return (1);
else if (child == 0) /* Child */
return (0);
/* Parent */
status = (wait(&status) != child);
return (status >= 0) ? 0 : 1;
}
], acx_cv_func_fork_works=yes, acx_cv_func_fork_works=no, acx_cv_func_fork_works=no)
])
AC_MSG_RESULT($acx_cv_func_fork_works)
if test $acx_cv_func_fork_works = no; then
AC_DEFINE(HAVE_NO_FORK)
fi
])
</pre>
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