minor changes

bin/pdfcompress

@@ -2,18 +2,22 @@
 
 set -euo pipefail
 
-function show_usage {
-    cat <<-END
-    usage: $0 [OPTIONS...] input_file output_file
+help_message="$(cat <<END
+usage: $(basename "$0") [OPTIONS...] INPUT_PDF OUTPUT_PDF
 
-    Converts a PDF file to a series of JPEG images using convert to
-    reduce the quality and then merges back the result in a single pdf 
+Converts a PDF file to a series of JPEG images using convert to reduce the quality 
+and then merges back the result in a single pdf 
+
+Options:
+    -q, --quality    Set the JPEG quality (default: 75)
+    -v, --verbose    Enable verbose output, also shows an estimate of remaining time
+    -h, --help       Display this help message
 
-    options:
-        -q, --quality    Set the JPEG quality (default: 75)
-        -v, --verbose    Enable verbose output
-        -h, --help       Display this help message
 END
+)"
+
+function show_usage() {
+    echo "$help_message"
     exit 1
 }