compton-trans: improve option parsing.

bin/compton-trans

@@ -7,6 +7,7 @@
 #
 
 # Usage:
+#  $ compton-trans [options] [+|-]opacity
 # By window id
 #   $ compton-trans -w "$WINDOWID" 75
 # By name
@@ -26,6 +27,7 @@ if test -z "$(command -v xprop)" -o -z "$(command -v xwininfo)"; then
 fi
 
 # Variables
+active=
 wprefix=
 window=
 opacity=
@@ -36,8 +38,17 @@ wid=
 topmost=
 lineno=
 
+# This takes into account the fact that getopts stops on
+# any argument it doesn't recongize or errors on. This
+# allows for things like `compton-trans -5` as well
+# as `compton-trans -c +5 -s` (contrived example).
+while test $# -gt 0; do
+  # Reset option index
+  OPTIND=1
+  LASTIND=1
+
   # Read options
-while getopts 'scdn:w:o:' option; do
+  while getopts ':scdn:w:o:' option "$@"; do
     case "$option" in
       s) wprefix=''; window='' ;;
       c)
@@ -49,20 +60,29 @@ while getopts 'scdn:w:o:' option; do
       n) wprefix='-name'; window=$OPTARG ;;
       w) wprefix='-id'; window=$OPTARG ;;
       o) opacity=$OPTARG ;;
-    \?) exit 1;;
+      \?)
+        # For some reason single char options `-x` stop on the OPTIND after the
+        # argument index, whereas two or more character options (`-foo`) stop
+        # on the argument's index, so we use LASTIND here instead. If OPTIND is
+        # not equal to LASTIND, this means -x was used instead of -xx.
+        OPTIND=$LASTIND
+        break
+      ;;
     esac
+    LASTIND=$OPTIND
   done
 
   # Read positional arguments
-shift $(($OPTIND - 1))
-test -n "$1" && opacity=$1
+  shift $((OPTIND - 1))
+  test -n "$1" && opacity=$1 && shift
+done
 
 # clean up opacity. xargs == a poor man's trim.
 opacity=$(echo "$opacity" | sed 's/%//g' | xargs)
 
 # Validate opacity value
-if test -z "$opacity" -a -z "$delete"; then
-  echo 'No opacity specified.'
+if test -z "$delete" && ! echo "$opacity" | grep -q '^[+-]\?[0-9]\+$'; then
+  echo "Invalid opacity specified: $opacity."
   exit 1
 fi