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-rw-r--r--networking/udhcp/pidfile.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/networking/udhcp/pidfile.c b/networking/udhcp/pidfile.c
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+/* pidfile.c
+ *
+ * Functions to assist in the writing and removing of pidfiles.
+ *
+ * Russ Dill <Russ.Dill@asu.edu> Soptember 2001
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "pidfile.h"
+#include "common.h"
+
+static char *saved_pidfile;
+
+static void pidfile_delete(void)
+{
+ if (saved_pidfile) unlink(saved_pidfile);
+}
+
+
+int pidfile_acquire(const char *pidfile)
+{
+ int pid_fd;
+ if (!pidfile) return -1;
+
+ pid_fd = open(pidfile, O_CREAT | O_WRONLY, 0644);
+ if (pid_fd < 0) {
+ LOG(LOG_ERR, "Unable to open pidfile %s: %m\n", pidfile);
+ } else {
+ lockf(pid_fd, F_LOCK, 0);
+ if (!saved_pidfile)
+ atexit(pidfile_delete);
+ saved_pidfile = (char *) pidfile;
+ }
+
+ return pid_fd;
+}
+
+
+void pidfile_write_release(int pid_fd)
+{
+ FILE *out;
+
+ if (pid_fd < 0) return;
+
+ if ((out = fdopen(pid_fd, "w")) != NULL) {
+ fprintf(out, "%d\n", getpid());
+ fclose(out);
+ }
+ lockf(pid_fd, F_UNLCK, 0);
+ close(pid_fd);
+}
+
+
+
+