MFC r304570,r321235:

r304570 (by trasz):

Add the "-n" flag to cron(8), to prevent it from daemonizing.
This makes it possible to use it with external supervisors.
The "-n" flag name is compatible with Linux, NetBSD, and OpenBSD.

r321235:

Fix trivial whitespace bug introduced in usage message changes for -n
support (r304570).

2 files changed, 11 insertions, 4 deletions

diff --git a/usr.sbin/cron/cron/cron.8 b/usr.sbin/cron/cron/cron.8
index 5d5a8d9..15bd995 100644
--- a/usr.sbin/cron/cron/cron.8
+++ b/usr.sbin/cron/cron/cron.8
@@ -17,7 +17,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 29, 2008
+.Dd August 21, 2016
 .Dt CRON 8
 .Os
 .Sh NAME
@@ -28,6 +28,7 @@
 .Op Fl j Ar jitter
 .Op Fl J Ar rootjitter
 .Op Fl m Ar mailto
+.Op Fl n
 .Op Fl s
 .Op Fl o
 .Op Fl x Ar debugflag Ns Op , Ns Ar ...
@@ -132,6 +133,8 @@ set to a null string, usually specified in a shell as
 .Li ''
 or
 .Li \*q\*q .
+.It Fl n
+Don't daemonize, run in foreground instead.
 .It Fl s
 Enable special handling of situations when the GMT offset of the local
 timezone changes, such as the switches between the standard time and
diff --git a/usr.sbin/cron/cron/cron.c b/usr.sbin/cron/cron/cron.c
index 0cdb9e3..0e58e81 100644
--- a/usr.sbin/cron/cron/cron.c
+++ b/usr.sbin/cron/cron/cron.c
@@ -49,6 +49,7 @@ static int	run_at_secres(cron_db *);
 
 static time_t	last_time = 0;
 static int	dst_enabled = 0;
+static int	dont_daemonize = 0;
 struct pidfh *pfh;
 
 static void
@@ -58,7 +59,7 @@ usage() {
 #endif
 
 	fprintf(stderr, "usage: cron [-j jitter] [-J rootjitter] "
-			"[-m mailto] [-s] [-o] [-x debugflag[,...]]\n");
+			"[-m mailto] [-n] [-s] [-o] [-x debugflag[,...]]\n");
 #if DEBUGGING
 	fprintf(stderr, "\ndebugflags: ");
 
@@ -136,7 +137,7 @@ main(argc, argv)
 	if (0) {
 # endif
 		(void) fprintf(stderr, "[%d] cron started\n", getpid());
-	} else {
+	} else if (dont_daemonize == 0) {
 		if (daemon(1, 0) == -1) {
 			pidfile_remove(pfh);
 			log_it("CRON",getpid(),"DEATH","can't become daemon");
@@ -512,7 +513,7 @@ parse_args(argc, argv)
 	int	argch;
 	char	*endp;
 
-	while ((argch = getopt(argc, argv, "j:J:m:osx:")) != -1) {
+	while ((argch = getopt(argc, argv, "j:J:m:nosx:")) != -1) {
 		switch (argch) {
 		case 'j':
 			Jitter = strtoul(optarg, &endp, 10);
@@ -529,6 +530,9 @@ parse_args(argc, argv)
 		case 'm':
 			defmailto = optarg;
 			break;
+		case 'n':
+			dont_daemonize = 1;
+			break;
 		case 'o':
 			dst_enabled = 0;
 			break;