1 files changed, 106 insertions, 0 deletions
diff --git a/lib/libutil/pidfile.c b/lib/libutil/pidfile.c
new file mode 100644
index 0000000..7c07a20
--- /dev/null
+++ b/lib/libutil/pidfile.c
@@ -0,0 +1,106 @@
+/*	$OpenBSD: pidfile.c,v 1.14 2019/06/28 14:20:40 schwarze Exp $	*/
+/*	$NetBSD: pidfile.c,v 1.4 2001/02/19 22:43:42 cgd Exp $	*/
+
+/*-
+ * Copyright (c) 1999 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe.
+ *
+ * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
+#include <sys/types.h>
+#include <errno.h>
+#include <paths.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <util.h>
+
+static char *pidfile_path;
+static pid_t pidfile_pid;
+
+static void pidfile_cleanup(void);
+
+extern char *__progname;
+
+int
+pidfile(const char *basename)
+{
+	int save_errno;
+	pid_t pid;
+	FILE *f;
+
+	if (basename == NULL)
+		basename = __progname;
+
+	free(pidfile_path);
+	pidfile_path = NULL;
+
+	/* _PATH_VARRUN includes trailing / */
+	if (asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename) == -1)
+		return (-1);
+
+	if ((f = fopen(pidfile_path, "w")) == NULL) {
+		save_errno = errno;
+		free(pidfile_path);
+		pidfile_path = NULL;
+		errno = save_errno;
+		return (-1);
+	}
+
+	pid = getpid();
+	if (fprintf(f, "%ld\n", (long)pid) <= 0 || fflush(f) != 0) {
+		save_errno = errno;
+		(void) fclose(f);
+		(void) unlink(pidfile_path);
+		free(pidfile_path);
+		pidfile_path = NULL;
+		errno = save_errno;
+		return (-1);
+	}
+	(void) fclose(f);
+
+	pidfile_pid = pid;
+	if (atexit(pidfile_cleanup) != 0) {
+		save_errno = errno;
+		(void) unlink(pidfile_path);
+		free(pidfile_path);
+		pidfile_path = NULL;
+		pidfile_pid = 0;
+		errno = save_errno;
+		return (-1);
+	}
+
+	return (0);
+}
+
+static void
+pidfile_cleanup(void)
+{
+
+	if (pidfile_path != NULL && pidfile_pid == getpid())
+		(void) unlink(pidfile_path);
+}