- Fail when the utility is not invoked as rtprio nor idprio.

 - use warnx() to tell the user whether a process is running in normal,
   idle or realtime priority. with the old code it would have been possible
   for another process to send data to stdout between
	printf("%s: ", p);
   and
	printf("* priority\n");
   and thus break the formatting.
 - 'rtprio 10 -0' triggeres non-intuitive behavior.  It would first set the
   priority of itself to 10 *and* would then try to execute '-0'. Of course,
   setting the priority of [id|rt]prio itself doesn't make a lot of sense,
   but it is intuitive compared to the previous behavior.
 - 'rtprio -t --1' will actually pass over the '-1' to rtprio().  Now
   invoking rtprio like this will catch the wrong usage before passing
   over the invalid argument to rtprio().
 - Garrett Cooper suggested to add further diagnostics where the failure
   occures, if execvp fails.

PR:		bin/154042
Submitted by:	arundel
MFC after:	1 month

1 files changed, 19 insertions, 23 deletions

diff --git a/usr.sbin/rtprio/rtprio.c b/usr.sbin/rtprio/rtprio.c
index 38dade8..bb72985 100644
--- a/usr.sbin/rtprio/rtprio.c
+++ b/usr.sbin/rtprio/rtprio.c
@@ -53,20 +53,17 @@ int
 main(int argc, char *argv[])
 {
 	struct rtprio rtp;
-	char *p;
-	pid_t proc;
+	const char *progname;
+	pid_t proc = 0;
 
-	/* find basename */
-	if ((p = rindex(argv[0], '/')) == NULL)
-		p = argv[0];
-	else
-		++p;
-	proc = 0;
+	progname = getprogname();
 
-	if (!strcmp(p, "rtprio"))
+	if (strcmp(progname, "rtprio") == 0)
 		rtp.type = RTP_PRIO_REALTIME;
-	else if (!strcmp(p, "idprio"))
+	else if (strcmp(progname, "idprio") == 0)
 		rtp.type = RTP_PRIO_IDLE;
+	else
+		errx(1, "invalid progname");
 
 	switch (argc) {
 	case 2:
@@ -76,20 +73,19 @@ main(int argc, char *argv[])
 	case 1:
 		if (rtprio(RTP_LOOKUP, proc, &rtp) != 0)
 			err(1, "RTP_LOOKUP");
-		printf("%s: ", p);
 		switch (rtp.type) {
 		case RTP_PRIO_REALTIME:
 		case RTP_PRIO_FIFO:
-			printf("realtime priority %d\n", rtp.prio);
+			warnx("realtime priority %d", rtp.prio);
 			break;
 		case RTP_PRIO_NORMAL:
-			printf("normal priority\n");
+			warnx("normal priority");
 			break;
 		case RTP_PRIO_IDLE:
-			printf("idle priority %d\n", rtp.prio);
+			warnx("idle priority %d", rtp.prio);
 			break;
 		default:
-			printf("invalid priority type %d\n", rtp.type);
+			errx(1, "invalid priority type %d", rtp.type);
 			break;
 		}
 		exit(0);
@@ -110,18 +106,18 @@ main(int argc, char *argv[])
 			break;
 		}
 
-		if (argv[2][0] == '-')
-			proc = parseint(argv[2] + 1, "pid");
-		if (rtprio(RTP_SET, proc, &rtp) != 0)
-			err(1, "RTP_SET");
-
-		if (proc == 0) {
+		if (argv[2][0] == '-') {
+			proc = parseint(argv[2], "pid");
+			proc = abs(proc);
+			if (rtprio(RTP_SET, proc, &rtp) != 0)
+				err(1, "RTP_SET");
+		} else {
 			execvp(argv[2], &argv[2]);
-			err(1, "%s", argv[2]);
+			err(1, "execvp: %s", argv[2]);
 		}
 		exit(0);
 	}
-	exit(1);
+	/* NOTREACHED */
 }
 
 static int