busybox/init/pidfilehack.c

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2003-05-11 22:52:39 +08:00
/*
* minit version 0.9.1 by Felix von Leitner
* ported to busybox by Glenn McGrath <bug1@optushome.com.au>
*
* 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.
*/
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/fcntl.h>
#include "busybox.h"
/* purpose: argv[1] is the full path to a PID file,
* argv+2 is the daemon to run.
* the daemon is expected to fork in the background and write its PID in
* the pid file.
*/
extern int pidfilehack_main(int argc, char **argv)
{
int count = 0;
if (argc < 3) {
bb_show_usage();
}
if (unlink(argv[2]) && (errno != ENOENT)) {
bb_perror_msg("could not remove pid file");
}
switch (fork()) {
case -1:
bb_perror_msg("could not fork");
return 2;
case 0: /* child */
execv(argv[3], argv + 3);
bb_perror_msg("execvp failed");
return 3;
}
do {
int fd = open(argv[2], O_RDONLY);
if (fd >= 0) {
static char buf[100] = "-P";
int len = read(fd, buf + 2, 100);
close(fd);
if (len > 0) {
char *_argv[] = { "msvc", 0, 0, 0 };
if (buf[len + 1] == '\n') {
buf[len + 1] = 0;
} else {
buf[len + 2] = 0;
}
_argv[1] = buf;
_argv[2] = argv[1];
execvp(_argv[0], _argv);
bb_perror_msg("execvp failed");
return 0;
}
}
sleep(1);
} while (++count < 30);
return(0);
}