Add the 'next' and 'prev' commands (aliased to '+' and '-') which skip

forward or backward by a specified number of tracks (defaulting to 1).
Use strvisx() to display the media catalog in case it contains unprintable
characters.  Sort includes.  Based on two patches submitted by PR, plus
style fixes and other changes of my own.

Submitted by:   Seth Kingsley <sethk@osd.bsdi.com>, Maxime Henrion <mux@qualys.com>
PR:             bin/22672, bin/26962
MFC After:      1 week

usr.sbin/cdcontrol/cdcontrol.1

@@ -44,9 +44,17 @@ Suffix `c' is added to the device name if needed.
 The available commands are listed below.  Only as many
 characters as are required to uniquely identify a command
 need be specified.
-Word
-.Em play
-can be omitted.
+The word
+.Cm play
+can be omitted or the characters 
+.Dq +
+and
+.Dq -
+can be used in the
+place of
+.Cm next
+and
+.Cm prev .
 .Bl -tag -width Cm
 .It Cm play Ar first_track Op Ar last_track
 Play from track 
@@ -82,6 +90,10 @@ Play starting from the logical block
 using
 .Ar length
 logical blocks.
+.It Cm next Op Ar tracks
+Skip forward a number of tracks (default 1).
+.It Cm prev Op Ar tracks
+Skip backward a number of tracks (default 1).
 .It Cm pause
 Stop playing.
 Do not stop the disc.

usr.sbin/cdcontrol/cdcontrol.c

@@ -23,19 +23,20 @@ static const char rcsid[] =
   "$FreeBSD$";
 #endif /* not lint */
 
+#include <sys/cdio.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/param.h>
 #include <ctype.h>
 #include <err.h>
 #include <errno.h>
+#include <histedit.h>
 #include <paths.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <sys/file.h>
-#include <sys/cdio.h>
-#include <sys/ioctl.h>
-#include <sys/param.h>
-#include <histedit.h>
+#include <vis.h>
 
 #define VERSION "2.0"
 
@@ -69,6 +70,8 @@ static const char rcsid[] =
 #define CMD_SET         13
 #define CMD_STATUS      14
 #define CMD_CDID        15
+#define CMD_NEXT        16
+#define CMD_PREVIOUS    17
 #define STATUS_AUDIO    0x1
 #define STATUS_MEDIA    0x2
 #define STATUS_VOLUME   0x4
@@ -85,11 +88,13 @@ struct cmdtab {
 { CMD_HELP,     "?",            1, 0 },
 { CMD_HELP,     "help",         1, "" },
 { CMD_INFO,     "info",         1, "" },
+{ CMD_NEXT,     "next",         1, "" },
 { CMD_PAUSE,    "pause",        2, "" },
 { CMD_PLAY,     "play",         1, "min1:sec1[.fram1] [min2:sec2[.fram2]]" },
 { CMD_PLAY,     "play",         1, "track1[.index1] [track2[.index2]]" },
 { CMD_PLAY,     "play",         1, "tr1 m1:s1[.f1] [[tr2] [m2:s2[.f2]]]" },
 { CMD_PLAY,     "play",         1, "[#block [len]]" },
+{ CMD_PREVIOUS, "previous",     2, "" },
 { CMD_QUIT,     "quit",         1, "" },
 { CMD_RESET,    "reset",        4, "" },
 { CMD_RESUME,   "resume",       1, "" },
@@ -115,6 +120,7 @@ int             play_track __P((int, int, int, int));
 int             get_vol __P((int *, int *));
 int             status __P((int *, int *, int *, int *));
 int             open_cd __P((void));
+int             next_prev __P((char *arg, int));
 int             play __P((char *arg));
 int             info __P((char *arg));
 int             cdid __P((void));
@@ -287,6 +293,16 @@ int run (int cmd, char *arg)
 
 		return pstatus (arg);
 
+	case CMD_NEXT:
+	case CMD_PREVIOUS:
+		if (fd < 0 && ! open_cd ())
+			return (0);
+
+		while (isspace (*arg))
+			arg++;
+
+		return next_prev (arg, cmd);
+
 	case CMD_PAUSE:
 		if (fd < 0 && ! open_cd ())
 			return (0);
@@ -690,6 +706,36 @@ int play (char *arg)
 	return (0);
 }
 
+int next_prev (char *arg, int cmd)
+{
+	struct ioc_toc_header h;
+	int dir, junk, n, off, rc, trk;
+
+	dir = (cmd == CMD_NEXT) ? 1 : -1;
+	rc = ioctl (fd, CDIOREADTOCHEADER, &h);
+	if (rc < 0)
+		return (rc);
+
+	n = h.ending_track - h.starting_track + 1;
+	rc = status (&trk, &junk, &junk, &junk);
+	if (rc < 0)
+		return (-1);
+
+	if (arg && *arg) {
+		if (sscanf (arg, "%u", &off) != 1) {
+		    warnx("invalid command argument");
+		    return (0);
+		} else
+		    trk += off * dir;
+	} else
+		trk += dir;
+
+	if (trk > h.ending_track)
+		trk = 1;
+
+	return (play_track (trk, 1, n, 1));
+}
+
 char *strstatus (int sts)
 {
 	switch (sts) {
@@ -710,7 +756,7 @@ int pstatus (char *arg)
 	struct cd_sub_channel_info data;
 	int rc, trk, m, s, f;
 	int what = 0;
-	char *p;
+	char *p, vmcn[(4 * 15) + 1];
 
 	while ((p = strtok(arg, " \t"))) {
 	    arg = 0;
@@ -750,8 +796,11 @@ int pstatus (char *arg)
 		       ss.data->what.media_catalog.mc_valid ? "": "in");
 		if (ss.data->what.media_catalog.mc_valid &&
 		    ss.data->what.media_catalog.mc_number[0])
-		    printf(", number \"%.15s\"",
-			   ss.data->what.media_catalog.mc_number);
+		{
+		    strvisx (vmcn, ss.data->what.media_catalog.mc_number,
+			    (sizeof (vmcn) - 1) / 4, VIS_OCTAL | VIS_NL);
+		    printf(", number \"%.*s\"", (int)sizeof (vmcn), vmcn);
+		}
 		putchar('\n');
 	    } else
 		printf("No media catalog info available\n");
@@ -1103,6 +1152,12 @@ char *parse (char *buf, int *cmd)
 	if (isdigit (*p) || (p[0] == '#' && isdigit (p[1]))) {
 		*cmd = CMD_PLAY;
 		return (p);
+	} else if (*p == '+') {
+		*cmd = CMD_NEXT;
+		return (p + 1);
+	} else if (*p == '-') {
+		*cmd = CMD_PREVIOUS;
+		return (p + 1);
 	}
 
 	for (buf = p; *p && ! isspace (*p); p++)