diff --git a/ch b/ch
old mode 100644
new mode 100755
index ed13153..7d640c6
--- a/ch
+++ b/ch
@@ -3,6 +3,31 @@
 # catch uninitialized variables
 set -u
 
+
+# display basic usage information
+display_basic_usage ()
+{
+    echo "Usage: $0 <command> [options]"
+    echo "Try '$0 --help' for more information."
+}
+
+
+# display detailed usage information
+display_detailed_usage ()
+{
+    echo "Usage: $0 <command> [options]"
+    echo "Extract help information for a given command and its options."
+    echo
+    echo "Options:"
+    echo "  --help    Show this help message and exit."
+    echo
+    echo "Examples:"
+    echo "  $0 ls --help"
+    echo "  $0 grep --invert-match"
+    exit 0
+}
+
+
 ###############################################
 # extract from line starting with search word
 # upto newline or line starting with -
@@ -24,6 +49,15 @@ extract_text ()
 }
 
 
+# Check for help option or no arguments
+if [[ "$#" -eq 0 ]]; then
+    display_basic_usage
+    exit 1
+elif [[ "$1" == "--help" ]]; then
+    display_detailed_usage
+fi
+
+
 ###############################################
 # variable to save command name
 # shift, for rest of arguments to be looped