Fixes and improvements in 2011/vik/try.sh

Check for perl(1) before trying to run ./raw2wav. If neither mplayer(1)
nor perl(1) are installed then the script tells the user to install one
or both and try again.

Function raw2wav() checks that perl(1) is installed. If it's not it
silently returns. With this change and the above it no longer makes any
assumption about what is installed and also tells the user what they
need to do if they don't have the proper tools installed.

Typo fix.

2011/vik/try.sh

@@ -17,14 +17,19 @@ make CC="$CC" all >/dev/null
 # clear screen after compilation so that only the entry is shown
 clear
 
-# fine mplayer
+# find mplayer
 MPLAYER="$(type -P mplayer)"
+# find perl
+PERL="$(type -P perl)"
 
 raw2wav()
 {
     if [[ "$#" != 2 ]]; then
 	echo "$0: raw2wav() expects two args, got: $#" 1>&2
 	return
+    elif [[ -z "$PERL" ]]; then
+	# silently return if perl not installed
+	return
     fi
 
     read -r -n 1 -p "Press any key to run: ./vik $1 > $2: "
@@ -40,10 +45,18 @@ raw2wav()
     echo 1>&2
 }
 
+if [[ -z "$MPLAYER" && -z "$PERL" ]]; then
+    echo "Neither mplayer(1) nor perl(1) installed. Please install one or" 1>&2
+    echo "both of these and try again." 1>&2
+    echo 1>&
+    exit 1
+fi
+
+# If we have mplayer we'll try playing the sounds directly. In either case,
+# if perl is installed, the alternate procedure will be run, creating WAV
+# files. If they do not have mplayer then if they have perl we will create WAV
+# files.
 if [[ -n "$MPLAYER" && -f "$MPLAYER" && -x "$MPLAYER" ]]; then
-    # If we have mplayer we'll try playing the sounds directly. If however it
-    # fails for some reason we will run the alternate procedure, creating WAV
-    # files.
     read -r -n 1 -p "Press any key to run: ./vik randowan.mod | $MPLAYER -demuxer rawaudio -: "
     echo 1>&2
     ./vik randowan.mod | mplayer -demuxer rawaudio -