freebsd-dev/gnu/libexec/uucp/libunix/iswait.c
1995-08-19 21:30:30 +00:00

160 lines
4.7 KiB
C

/* iswait.c
Wait for a process to finish.
Copyright (C) 1992 Ian Lance Taylor
This file is part of the Taylor UUCP package.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
The author of the program may be contacted at ian@airs.com or
c/o Cygnus Support, 48 Grove Street, Somerville, MA 02144.
*/
#include "uucp.h"
#include "uudefs.h"
#include "sysdep.h"
#include <errno.h>
#if HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
/* We use a typedef wait_status for wait (waitpid, wait4) to put
results into. We define the POSIX examination functions we need if
they are not already defined (if they aren't defined, I assume that
we have a standard wait status). */
#if HAVE_UNION_WAIT
typedef union wait wait_status;
#ifndef WIFEXITED
#define WIFEXITED(u) ((u).w_termsig == 0)
#endif
#ifndef WEXITSTATUS
#define WEXITSTATUS(u) ((u).w_retcode)
#endif
#ifndef WTERMSIG
#define WTERMSIG(u) ((u).w_termsig)
#endif
#else /* ! HAVE_UNION_WAIT */
typedef int wait_status;
#ifndef WIFEXITED
#define WIFEXITED(i) (((i) & 0xff) == 0)
#endif
#ifndef WEXITSTATUS
#define WEXITSTATUS(i) (((i) >> 8) & 0xff)
#endif
#ifndef WTERMSIG
#define WTERMSIG(i) ((i) & 0x7f)
#endif
#endif /* ! HAVE_UNION_WAIT */
/* Wait for a particular process to finish. The ipid argument should
be pid_t, but then we couldn't have a prototype. If the zreport
argument is not NULL, then a wait error will be logged, and if the
exit status is non-zero it will be logged with zreport as the
header of the log message. If the zreport argument is NULL, no
errors will be logged. This function returns the exit status if
the process exited normally, or -1 on error or if the process was
killed by a signal (I don't just always return the exit status
because then the calling code would have to prepared to handle
union wait status vs. int status, and none of the callers care
which signal killed the program anyhow).
This functions keeps waiting until the process finished, even if it
is interrupted by a signal. I think this is right for all uses.
The controversial one would be when called from uuxqt to wait for a
requested process. Hitting uuxqt with SIGKILL will approximate the
actions taken if we return from here with an error anyhow. If we
do get a signal, we call ulog with a NULL argument to get it in the
log file at about the right time. */
int
ixswait (ipid, zreport)
unsigned long ipid;
const char *zreport;
{
wait_status istat;
#if HAVE_WAITPID
while (waitpid ((pid_t) ipid, (pointer) &istat, 0) < 0)
{
if (errno != EINTR)
{
if (zreport != NULL)
ulog (LOG_ERROR, "waitpid: %s", strerror (errno));
return -1;
}
ulog (LOG_ERROR, (const char *) NULL);
}
#else /* ! HAVE_WAITPID */
#if HAVE_WAIT4
while (wait4 ((pid_t) ipid, (pointer) &istat, 0,
(struct rusage *) NULL) < 0)
{
if (errno != EINTR)
{
if (zreport != NULL)
ulog (LOG_ERROR, "wait4: %s", strerror (errno));
return -1;
}
ulog (LOG_ERROR, (const char *) NULL);
}
#else /* ! HAVE_WAIT4 */
pid_t igot;
/* We could theoretically get the wrong child here if we're in some
kind of weird pipeline, so we don't give any error messages for
it. */
while ((igot = wait ((pointer) &istat)) != (pid_t) ipid)
{
if (igot < 0)
{
if (errno != EINTR)
{
if (zreport != NULL)
ulog (LOG_ERROR, "wait: %s", strerror (errno));
return -1;
}
ulog (LOG_ERROR, (const char *) NULL);
}
}
#endif /* ! HAVE_WAIT4 */
#endif /* ! HAVE_WAITPID */
DEBUG_MESSAGE2 (DEBUG_EXECUTE, "%s %d",
WIFEXITED (istat) ? "Exit status" : "Signal",
WIFEXITED (istat) ? WEXITSTATUS (istat) : WTERMSIG (istat));
if (WIFEXITED (istat) && WEXITSTATUS (istat) == 0)
return 0;
if (zreport != NULL)
{
if (! WIFEXITED (istat))
ulog (LOG_ERROR, "%s: Got signal %d", zreport, WTERMSIG (istat));
else
ulog (LOG_ERROR, "%s: Exit status %d", zreport,
WEXITSTATUS (istat));
}
if (WIFEXITED (istat))
return WEXITSTATUS (istat);
else
return -1;
}