Print options only supported by device, back out printing options separately

Pointed-by: bde

2 files changed, 25 insertions, 41 deletions

diff --git a/sbin/comcontrol/comcontrol.8 b/sbin/comcontrol/comcontrol.8
index 84ef5b5..7e5d1ad 100644
--- a/sbin/comcontrol/comcontrol.8
+++ b/sbin/comcontrol/comcontrol.8
@@ -7,9 +7,9 @@
 .Nd control an special tty device.
 .Sh SYNOPSIS
 .Nm comcontrol
-.Ar special_device | -
-.Op dtrwait Op number
-.Op drainwait Op number
+.Ar special_device | Fl
+.Op dtrwait Ar number
+.Op drainwait Ar number
 .Sh DESCRIPTION
 .Nm Comcontrol
 is used to examine and modify some of the special characteristics
@@ -22,8 +22,6 @@ Only the superuser can change the settings.
 .Pp
 The following options are available:
 .Bl -tag -width indent
-.It Cm dtrwait
-Print current DTR wait time.
 .It Cm dtrwait Ar number
 Set the time to wait after dropping DTR
 to the given number.
@@ -31,8 +29,6 @@ The units are hundredths of a second.
 The default is 300 hundredths, i.e., 3 seconds.
 This option needed mainly to set proper recover time after
 modem reset.
-.It Cm drainwait
-Print current output drain timeout.
 .It Cm drainwait Ar number
 Set the time to wait for output drain
 to the given number.
diff --git a/sbin/comcontrol/comcontrol.c b/sbin/comcontrol/comcontrol.c
index 7de2225..ad77b98 100644
--- a/sbin/comcontrol/comcontrol.c
+++ b/sbin/comcontrol/comcontrol.c
@@ -33,6 +33,7 @@ static const char rcsid[] =
 
 #include <ctype.h>
 #include <err.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -44,7 +45,7 @@ static void
 usage()
 {
 	fprintf(stderr,
-	"usage: comcontrol <filename|-> [dtrwait [<n>]] [drainwait [<n>]]\n");
+	"usage: comcontrol <filename>|- [dtrwait <n>] [drainwait <n>]\n");
 	exit(1);
 }
 
@@ -53,9 +54,8 @@ main(int argc, char *argv[])
 {
 	int	fd;
 	int     res = 0;
+	int     print_dtrwait = 1, print_drainwait = 1;
 	int     dtrwait = -1, drainwait = -1;
-	int     temp;
-	int     output = 0;
 
 	if (argc < 2)
 		usage();
@@ -69,50 +69,40 @@ main(int argc, char *argv[])
 			return 1;
 		}
 	}
-
 	if (argc == 2) {
 		if (ioctl(fd, TIOCMGDTRWAIT, &dtrwait) < 0) {
-			res = 1;
-			warn("TIOCMGDTRWAIT");
+			print_dtrwait = 0;
+			if (errno != ENOTTY) {
+				res = 1;
+				warn("TIOCMGDTRWAIT");
+			}
 		}
 		if (ioctl(fd, TIOCGDRAINWAIT, &drainwait) < 0) {
-			res = 1;
-			warn("TIOCGDRAINWAIT");
+			print_drainwait = 0;
+			if (errno != ENOTTY) {
+				res = 1;
+				warn("TIOCGDRAINWAIT");
+			}
 		}
-		printf("dtrwait %d drainwait %d ", dtrwait, drainwait);
-		output = 1;
+		if (print_dtrwait)
+			printf("dtrwait %d ", dtrwait);
+		if (print_drainwait)
+			printf("drainwait %d ", drainwait);
+		printf("\n");
 	} else {
 		while (argv[2] != NULL) {
 			if (!strcmp(argv[2],"dtrwait")) {
-				if (argv[3] == NULL || !isdigit(argv[3][0])) {
-					if (ioctl(fd, TIOCMGDTRWAIT, &temp) < 0) {
-						res = 1;
-						temp = -1;
-						warn("TIOCMGDTRWAIT");
-					}
-					printf("dtrwait %d ", temp);
-					output = 1;
-					argv++;
-					continue;
-				}
 				if (dtrwait >= 0)
 					usage();
+				if (argv[3] == NULL || !isdigit(argv[3][0]))
+					usage();
 				dtrwait = atoi(argv[3]);
 				argv += 2;
 			} else if (!strcmp(argv[2],"drainwait")) {
-				if (argv[3] == NULL || !isdigit(argv[3][0])) {
-					if (ioctl(fd, TIOCGDRAINWAIT, &temp) < 0) {
-						res = 1;
-						temp = -1;
-						warn("TIOCGDRAINWAIT");
-					}
-					printf("drainwait %d ", temp);
-					argv++;
-					output = 1;
-					continue;
-				}
 				if (drainwait >= 0)
 					usage();
+				if (argv[3] == NULL || !isdigit(argv[3][0]))
+					usage();
 				drainwait = atoi(argv[3]);
 				argv += 2;
 			} else
@@ -133,7 +123,5 @@ main(int argc, char *argv[])
 	}
 
 	close(fd);
-	if (output)
-		printf("\n");
 	return res;
 }