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

1 files changed, 15 insertions, 3 deletions

diff --git a/usr.sbin/cdcontrol/cdcontrol.1 b/usr.sbin/cdcontrol/cdcontrol.1
index 010e783..12afdd5 100644
--- a/usr.sbin/cdcontrol/cdcontrol.1
+++ b/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.