added possibility to document template parameters

template.sh

@@ -2,11 +2,20 @@
 
 while test $# -gt 0; do
     case "$1" in
-        (-h|--help) cat <<EOF
+        (-h|--help) if test -e "${!#}"; then
+                        cat <<EOF
+$0 $(sed -n 's,^ *# *,,p' "${!#}" | tr '\n' ' ') ${!#}
+EOF
+                    else
+                        cat <<EOF
 $0 [OPTIONS] FILE
 
 OPTIONS
 
+  -h, --help             Show this help
+
+  -h, --help file        Show usage of template file (if documented)
+
   -v, --var  name=value  Set environment variable to be used in the template.
 
   -p, --pwd  name        Generate a random password with the given name.
@@ -17,6 +26,9 @@ FILE
   and execute bash commands, e.g. you are allowed wo use the \$()
   expression.
 
+  Document the parameters that shall be used in comment lines, this
+  are lines thet start with # followed by -v or -p options.
+
 DESCRIPTION
 
   Parse a template file and generate an instance for it, using the
@@ -27,6 +39,9 @@ EXAMPLE
 
   file wordpress.tpl
 -----------------------------------------------------------------------------
+# -v NAME=
+# -v PORT=
+# -p PASSWORD
 version: '3.3'
 services:
   mysql:
@@ -68,6 +83,7 @@ services:
   $0 -v NAME=my-site -v PORT=8006 -p PASSWORD wordpress.tpl > my-site.yaml
 
 EOF
+                    fi
                     exit;;
         (-v|--var) shift;
                    if [[ $1 =~ ^[a-zA-Z][a-zA-Z0-9_]*= ]]; then
@@ -107,6 +123,6 @@ if ! test -e "$file"; then
     exit 1
 fi
 
-eval "cat <<EOFXXXX
+eval "sed '/^ *#/d' <<EOFXXXX
 $(<$file)
 EOFXXXX"