Add help message to autopape.sh

autopape.sh

@@ -1,23 +1,38 @@
 #!/bin/sh
-# simple script to loop through each image in a directory and set said image as wallpaper for a specififed interval using feh
+# simple script to loop through each image in a directory and set said image as wallpaper for a specified interval
 
 command="feh --bg-fill"
 interval="1m"
 
-while getopts 'c:i:' flag; do
+usage() {
+    cat << EOF
+Usage: autopape.sh [OPTIONS]... [ARGUMENTS]...
+Iterate over the files in a directory and set them as the desktop wallpaper at a regular interval.
+Options:
+    -c  Specify the command that should be used to set the wallpaper. Defaults to 'feh --bg-fill'
+    -h  Print this help message
+    -i  Specify the interval between wallpaper changes. Defaults to '1m'
+EOF
+}
+
+while getopts 'c:i:h' flag; do
     case "${flag}" in
         c)
             command="${OPTARG}";;
 
         i) 
             interval="${OPTARG}";;
+
+        h)
+            usage
+            exit 0;;
+
         *)
-            echo "Unrecognised option"
+            usage
             exit 1;;
     esac
 done
 
-
 while [ true ]
 do
     for img in *