117 lines
2.7 KiB
C
117 lines
2.7 KiB
C
/*
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flock - acquires a file lock and executes a command with the lock held.
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Usage: flock [--shared | --timeout=seconds] lockfile program [args...]
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Written by Adam J. Richter
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Copyright (C) 2004 Yggdrasil Computing, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <sys/file.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <getopt.h>
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#include <unistd.h>
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#include <stdlib.h> /* exit */
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#include <signal.h> /* kill */
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#include <stdio.h>
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#include "nls.h"
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static int non_blocking = 0;
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static int shared = LOCK_EX;
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static const struct option options[] = {
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{"shared", no_argument, &shared, LOCK_SH },
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{"timeout", required_argument, NULL, 't' },
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{NULL, 0, NULL, 0 },
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};
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int main(int argc, char **argv)
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{
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int fd;
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int opt;
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int pid;
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int child_status;
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int option_index;
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int timeout = 0;
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setlocale(LC_ALL, "");
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bindtextdomain(PACKAGE, LOCALEDIR);
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textdomain(PACKAGE);
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do {
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opt = getopt_long(argc, argv, "+", options, &option_index);
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switch(opt) {
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case '?':
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fprintf (stderr,
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_("flock: unknown option, aborting.\n"));
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exit(1);
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break;
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case 't':
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timeout = atoi(optarg);
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if (timeout == 0)
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non_blocking |= LOCK_NB;
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break;
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default:
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break;
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}
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} while (opt != -1);
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argc -= optind;
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argv += optind;
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if (argc < 2) {
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fprintf(stderr,
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_("Usage flock [--shared] [--timeout=seconds] "
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"filename command {arg arg...}\n"));
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exit(2);
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}
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fd = open(argv[0], O_RDONLY);
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if (fd < 0) {
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perror(argv[0]);
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exit(3);
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}
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alarm(timeout);
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if (flock(fd, shared | non_blocking) != 0) {
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perror("flock");
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exit(4);
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}
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alarm(0);
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pid = fork();
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if (pid < 0) {
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perror("fork");
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exit(5);
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}
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if (pid == 0) {
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execvp(argv[1], argv+1);
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perror(argv[1]);
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exit(6);
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}
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waitpid(pid, &child_status, 0);
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/* flock(fd, LOCK_UN); */
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/* No need to explicitly release the flock, since we are just
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going to exit now anyhow. */
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/* Lame attempt to simulate child's mode of death. */
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if (WIFSIGNALED(child_status))
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kill(0, WTERMSIG(child_status));
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return WEXITSTATUS(child_status);
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}
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