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/* GNU Mailutils -- a suite of utilities for electronic mail
Copyright (C) 1999-2025 Free Software Foundation, Inc.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General
Public License along with this library. If not, see
<http://www.gnu.org/licenses/>. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/wait.h>
/* See Advanced Programming in the UNIX Environment, Stevens,
* program 10.20 for the rational for the signal handling. I
* had to look it up, so if somebody else is curious, that's where
* to find it.
*/
int
mu_spawnvp (const char *prog, char *av[], int *stat)
{
pid_t pid;
int err = 0;
int progstat;
struct sigaction ignore;
struct sigsave {
int signo;
void *handler;
int saved;
struct sigaction act;
};
static struct sigsave sigsave[] = {
{ SIGINT, SIG_IGN, 0 },
{ SIGQUIT, SIG_IGN, 0 },
{ SIGCHLD, SIG_DFL, 0 }
};
static int nsigsave = sizeof (sigsave) / sizeof (sigsave[0]);
int i;
sigset_t chldmask;
sigset_t savemask;
if (!prog || !av)
return EINVAL;
ignore.sa_flags = 0;
sigemptyset (&ignore.sa_mask);
for (i = 0; i < nsigsave; i++)
{
ignore.sa_handler = sigsave[i].handler;
if (sigaction (sigsave[i].signo, &ignore, &sigsave[i].act) < 0)
{
err = errno;
break;
}
sigsave[i].saved = 1;
}
if (err == 0)
{
sigemptyset (&chldmask); /* now block SIGCHLD */
sigaddset (&chldmask, SIGCHLD);
if (sigprocmask (SIG_BLOCK, &chldmask, &savemask) < 0)
err = errno;
else
{
pid = fork ();
if (pid < 0)
{
err = errno;
}
else if (pid == 0)
{ /* child */
for (i = 0; i < nsigsave; i++)
{
sigaction (sigsave[i].signo, &sigsave[i].act, NULL);
}
sigprocmask (SIG_SETMASK, &savemask, NULL);
execvp (prog, av);
_exit (127); /* exec error */
}
else
{ /* parent */
while (waitpid (pid, &progstat, 0) < 0)
if (errno != EINTR)
{
err = errno; /* error other than EINTR from waitpid() */
break;
}
if (err == 0 && stat)
*stat = progstat;
}
}
}
/* restore previous signal actions & reset signal mask */
for (i = 0; i < nsigsave; i++)
{
if (!sigsave[i].saved)
break;
if (sigaction (sigsave[i].signo, &sigsave[i].act, NULL) < 0)
err = err ? err : errno;
}
if (sigprocmask (SIG_SETMASK, &savemask, NULL) < 0)
err = err ? err : errno;
return err;
}
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