Makefile: add check that manpage and command options match.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

doc/Makefile

@@ -62,6 +62,11 @@ doc/full-states.dot: test/test_state_coverage
 
 maintainer-clean: doc-maintainer-clean
 clean: doc-clean
+check: check-manpages
+
+check-manpages: cli/lightning-cli lightningd/lightningd
+	@tools/check-manpage.sh cli/lightning-cli doc/lightning-cli.1.txt
+	@tools/check-manpage.sh lightningd/lightningd doc/lightningd-config.5.txt
 
 doc-maintainer-clean:
 	$(RM) doc/deployable-lightning.pdf

tools/check-manpage.sh

@@ -0,0 +1,39 @@
+#! /bin/bash
+# Needs bash for process substitition, ie <(
+
+if [ $# != 2 ]; then
+    echo "Usage $0 <command> <asciidoc.txt>" >&2
+    exit 1
+fi
+
+get_cmd_opts()
+{
+    # Trim out -- after first one (--option mentioned in help!)
+    $1 --help | grep '^-' | sed 's/[ 	].*--.*//' | while IFS=$'\n' read -r opt; do
+	case "$opt" in
+	    # We don't document dev options.
+	    --dev*)
+		;;
+	    --*=*|--*' <arg>'*)
+		echo "${opt%%[ =]*}=" | cut -c3-
+		;;
+	    --*)
+		echo "${opt%%[ 	|]*}" | cut -c3-
+		;;
+	    -*\|--*)
+		opt=${opt##*|}
+		echo "${opt%%[ 	|]*}" | cut -c3-
+	esac
+    done
+}
+
+CMD_OPTNAMES=$(get_cmd_opts "$1" | sort)
+
+# Now, gather (long) opt names from man page, make sure they match.
+MAN_OPTNAMES=$(sed -n 's/^\*\(--\)\?\([^*/]*\)\*\(=\?\).*::/\2\3/p' < "$2" | sort)
+
+if [ "$CMD_OPTNAMES" != "$MAN_OPTNAMES" ]; then
+    echo "diff of command names vs manpage names":
+    diff -u <(echo "$CMD_OPTNAMES") <(echo "$MAN_OPTNAMES")
+    exit 2
+fi