From 0567de2636ff0ed0a9dc378cdbd82e0bb7dce788 Mon Sep 17 00:00:00 2001
From: Nick Bowler <nbowler@draconx.ca>
Date: Wed, 29 Sep 2021 21:58:46 -0400
Subject: [PATCH] help: Add a single-dash long option mode.

For programs using getopt_long_only with single-dash long options, add a
compile time flag to select a mode that produces more appropriate help
output.  This is typical of command-line options for X applications.
---
 Makefile.am        |  9 ++++++++-
 src/help.c         | 35 +++++++++++++++++++++++++++++++++++
 t/.gitignore       |  1 +
 tests/functions.at | 29 +++++++++++++++++++++++++++++
 4 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/Makefile.am b/Makefile.am
index a9f7934..3f976b1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -18,10 +18,17 @@ t_packtestu64_SOURCES = t/packtestu64.c src/pack.c src/tap.c
 t_packtests64_SOURCES = t/packtests64.c src/pack.c src/tap.c
 
 if HAVE_STRUCT_OPTION
-check_PROGRAMS += t/helpdesc t/helpopt
+check_PROGRAMS += t/helpdesc t/helpopt t/helpopt2
 endif
 
+EXTRA_LIBRARIES = libglohelp.a
+libglohelp_a_SOURCES = src/help.c
+libglohelp_a_CFLAGS = -DHELP_GETOPT_LONG_ONLY
+libglohelp_a_SHORTNAME = glo
+
 t_helpopt_SOURCES = t/helpopt.c src/help.c src/tap.c
+t_helpopt2_SOURCES = t/helpopt.c src/tap.c
+t_helpopt2_LDADD = $(libglohelp_a_OBJECTS)
 t_helpdesc_SOURCES = t/helpdesc.c src/help.c src/tap.c
 
 DISTCLEANFILES =
diff --git a/src/help.c b/src/help.c
index 0ceb8f4..d1dd5f5 100644
--- a/src/help.c
+++ b/src/help.c
@@ -71,6 +71,25 @@ int help_print_optstring(const struct option *opt, const char *argname, int l)
 		goto no_translate;
 
 	switch (option_type(opt)) {
+#if HELP_GETOPT_LONG_ONLY
+	case OPT_SHORT_WITH_OPTIONAL_ARG:
+	case OPT_LONG_WITH_OPTIONAL_ARG:
+		w = snprintf(optstring, sizeof optstring,
+		             _("  -%s [%s]"), opt->name,
+		             pgettext_expr(opt->name, argname));
+		break;
+	case OPT_SHORT_WITH_MANDATORY_ARG:
+	case OPT_LONG_WITH_MANDATORY_ARG:
+		w = snprintf(optstring, sizeof optstring,
+		             _("  -%s %s"), opt->name,
+		             pgettext_expr(opt->name, argname));
+		break;
+	case OPT_SHORT_WITHOUT_ARG:
+	case OPT_LONG_WITHOUT_ARG:
+		w = snprintf(optstring, sizeof optstring,
+		             _("  -%s"), opt->name);
+		break;
+#else
 	case OPT_SHORT_WITH_OPTIONAL_ARG:
 		w = snprintf(optstring, sizeof optstring,
 		             _("  -%c, --%s[=%s]"), opt->val, opt->name,
@@ -99,6 +118,7 @@ int help_print_optstring(const struct option *opt, const char *argname, int l)
 		w = snprintf(optstring, sizeof optstring,
 		             _("  --%s"), opt->name);
 		break;
+#endif
 	default:
 		assert(0);
 	}
@@ -112,6 +132,20 @@ int help_print_optstring(const struct option *opt, const char *argname, int l)
 
 no_translate:
 	switch (option_type(opt)) {
+#if HELP_GETOPT_LONG_ONLY
+	case OPT_SHORT_WITH_OPTIONAL_ARG:
+	case OPT_LONG_WITH_OPTIONAL_ARG:
+		w = printf("  -%s [%s]", opt->name, argname);
+		break;
+	case OPT_SHORT_WITH_MANDATORY_ARG:
+	case OPT_LONG_WITH_MANDATORY_ARG:
+		w = printf("  -%s %s", opt->name, argname);
+		break;
+	case OPT_SHORT_WITHOUT_ARG:
+	case OPT_LONG_WITHOUT_ARG:
+		w = printf("  -%s", opt->name);
+		break;
+#else
 	case OPT_SHORT_WITH_OPTIONAL_ARG:
 		w = printf("  -%c, --%s[=%s]", opt->val, opt->name, argname);
 		break;
@@ -130,6 +164,7 @@ no_translate:
 	case OPT_LONG_WITHOUT_ARG:
 		w = printf("  --%s", opt->name);
 		break;
+#endif
 	default:
 		assert(0);
 	}
diff --git a/t/.gitignore b/t/.gitignore
index 7fee3da..acb4e4e 100644
--- a/t/.gitignore
+++ b/t/.gitignore
@@ -1,4 +1,5 @@
 /helpdesc
 /helpopt
+/helpopt2
 /packtest[su]
 /packtest[su]64
diff --git a/tests/functions.at b/tests/functions.at
index 507c105..dbbcf6d 100644
--- a/tests/functions.at
+++ b/tests/functions.at
@@ -80,3 +80,32 @@ AT_CHECK([m4_join([ ],
 ]])
 
 AT_CLEANUP
+
+AT_SETUP([help_print_optstring (getopt_long_only)])
+
+AT_SKIP_IF([test ! -x "$builddir/t/helpopt2"])
+
+AT_CHECK([m4_join([ ],
+  ["$builddir/t/helpopt2"],
+  [--foo],
+  [--bar -b],
+  [--baz ARG],
+  [--baz -B ARG],
+  [--quux '@<:@ARG@:>@'],
+  [--quux -q '@<:@ARG@:>@'],
+  [--hello-this-is-a-very-long-option 20],
+  [--hello-this-is-a-very-long-option 50],
+  [--not-long 12])], [0],
+[[  -foo	6
+  -bar	6
+  -baz ARG	10
+  -baz ARG	10
+  -quux [ARG]	13
+  -quux [ARG]	13
+  -hello-this-is-a-very-long-option
+	0
+  -hello-this-is-a-very-long-option	35
+  -not-long	11
+]])
+
+AT_CLEANUP
-- 
2.43.2