freebsd-skq/bin/pwait/pwait.c
jilles 0a8c57af78 Add pwait utility, which waits for any process to terminate.
This is similar to the Solaris utility of the same name.

Some use cases:
* rc.subr's wait_for_pids
* interactive use, e.g. to shut down the computer when some task is done
  even if the task is already running

Discussed on:	hackers@
2009-11-17 22:47:20 +00:00

146 lines
3.4 KiB
C

/*-
* Copyright (c) 2004-2009, Jilles Tjoelker
* All rights reserved.
*
* Redistribution and use in source and binary forms, with
* or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and
* the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
static void
usage(void)
{
fprintf(stderr, "usage: pwait [-v] pid ...\n");
exit(EX_USAGE);
}
/*
* pwait - wait for processes to terminate
*/
int
main(int argc, char *argv[])
{
int kq;
struct kevent *e;
int verbose = 0;
int opt, nleft, n, i, duplicate, status;
long pid;
char *s, *end;
while ((opt = getopt(argc, argv, "v")) != -1) {
switch (opt) {
case 'v':
verbose = 1;
break;
default:
usage();
/* NOTREACHED */
}
}
argc -= optind;
argv += optind;
if (argc == 0)
usage();
kq = kqueue();
if (kq == -1)
err(1, "kqueue");
e = malloc(argc * sizeof(struct kevent));
if (e == NULL)
err(1, "malloc");
nleft = 0;
for (n = 0; n < argc; n++) {
s = argv[n];
if (!strncmp(s, "/proc/", 6)) /* Undocumented Solaris compat */
s += 6;
errno = 0;
pid = strtol(s, &end, 10);
if (pid < 0 || *end != '\0' || errno != 0) {
warnx("%s: bad process id", s);
continue;
}
duplicate = 0;
for (i = 0; i < nleft; i++)
if (e[i].ident == (uintptr_t)pid)
duplicate = 1;
if (!duplicate) {
EV_SET(e + nleft, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT,
0, NULL);
if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
warn("%ld", pid);
else
nleft++;
}
}
while (nleft > 0) {
n = kevent(kq, NULL, 0, e, nleft, NULL);
if (n == -1)
err(1, "kevent");
if (verbose)
for (i = 0; i < n; i++) {
status = e[i].data;
if (WIFEXITED(status))
printf("%ld: exited with status %d.\n",
(long)e[i].ident,
WEXITSTATUS(status));
else if (WIFSIGNALED(status))
printf("%ld: killed by signal %d.\n",
(long)e[i].ident,
WTERMSIG(status));
else
printf("%ld: terminated.\n",
(long)e[i].ident);
}
nleft -= n;
}
return 0;
}