[mm]: Add `--help` option support to mmroff.

* mmroff.pl: Recognize `--help` option.
* mmroff.1.man (Synopsis, Options): Document.

3 files changed, 23 insertions, 4 deletions

diff --git a/contrib/mm/ChangeLog b/contrib/mm/ChangeLog
index 31e8b08cd..acb0937e7 100644
--- a/contrib/mm/ChangeLog
+++ b/contrib/mm/ChangeLog
@@ -1,3 +1,10 @@
+2023-02-17  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+	[mm]: Add `--help` option support to mmroff.
+
+	* mmroff.pl: Recognize `--help` option.
+	* mmroff.1.man (Synopsis, Options): Document.
+
 2023-02-01  G. Branden Robinson <g.branden.robinson@gmail.com>
 
 	* m.tmac (H, SETR): Trivially refactor.  Rename register to
diff --git a/contrib/mm/mmroff.1.man b/contrib/mm/mmroff.1.man
index e47957ce2..2c9f3c24b 100644
--- a/contrib/mm/mmroff.1.man
+++ b/contrib/mm/mmroff.1.man
@@ -56,6 +56,11 @@ macro package
 .
 .
 .SY mmroff
+.B \-\-help
+.YS
+.
+.
+.SY mmroff
 .B \-\-version
 .YS
 .
@@ -86,11 +91,13 @@ when the cross-reference file is up to date.
 .SH Options
 .\" ====================================================================
 .
-If called with the
+.B \-\-help
+displays
+a usage message,
+while
 .B \-\-version
-option,
-.I mmroff
-displays its version information and exits.
+shows version information;
+both exit afterward.
 .
 .
 .TP
diff --git a/contrib/mm/mmroff.pl b/contrib/mm/mmroff.pl
index 5688b53f9..af8bf906e 100644
--- a/contrib/mm/mmroff.pl
+++ b/contrib/mm/mmroff.pl
@@ -29,6 +29,11 @@ use warnings;
 
 my $no_exec;
 
+if (grep(/^--help$/, @ARGV)) {
+	print "usage: mmroff [-x] [groff-option ...] [file ...]\n";
+	exit;
+}
+
 if (grep(/^--version$/, @ARGV)) {
 	print "mmroff (groff) @VERSION@\n";
 	exit;