1 files changed, 75 insertions, 0 deletions
diff --git a/networking/udhcp/pidfile.c b/networking/udhcp/pidfile.c
new file mode 100644
index 000000000..7a956fb47
--- /dev/null
+++ b/networking/udhcp/pidfile.c
@@ -0,0 +1,75 @@
+/* pidfile.c
+ *
+ * Functions to assist in the writing and removing of pidfiles.
+ *
+ * Russ Dill <Russ.Dill@asu.edu> September 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 "common.h"
+#include "pidfile.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);
+}
+
+
+
+