>From a882a0bdf4b2d19b25f42bb2d4194b526dde8589 Mon Sep 17 00:00:00 2001
From: Bernhard Voelker <address@hidden>
Date: Thu, 29 Nov 2018 09:06:26 +0100
Subject: [PATCH] long-options: add parse_gnu_standard_options_only

* lib/long-options.c (parse_long_options): Use EXIT_SUCCESS instead
of 0.
(parse_gnu_standard_options_only): Add function to
process the GNU default options --help and --version (see also [1]),
and fail for any other unknown long or short option.
* lib/long-options.h (parse_gnu_standard_options_only): Declare it.
[1]
https://gnu.org/prep/standards/html_node/Command_002dLine-Interfaces.html
---
 ChangeLog            | 12 +++++++++
 lib/long-options.c   | 58 +++++++++++++++++++++++++++++++++++++++++++-
 lib/long-options.h   | 16 ++++++++++++
 modules/long-options |  1 +
 4 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index af7a14fa9..3b25962b6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2018-11-29  Bernhard Voelker  <address@hidden>
+
+	long-options: add parse_gnu_standard_options_only
+	* lib/long-options.c (parse_long_options): Use EXIT_SUCCESS instead
+	of 0.
+	(parse_gnu_standard_options_only): Add function to
+	process the GNU default options --help and --version (see also [1]),
+	and fail for any other unknown long or short option.
+	* lib/long-options.h (parse_gnu_standard_options_only): Declare it.
+	[1]
+	https://gnu.org/prep/standards/html_node/Command_002dLine-Interfaces.html
+
 2018-11-29  Akim Demaille  <address@hidden>
 
 	bitset: rename ebitset/expandable.* as tbitset/table.*
diff --git a/lib/long-options.c b/lib/long-options.c
index eef1f2f35..b3f1df404 100644
--- a/lib/long-options.c
+++ b/lib/long-options.c
@@ -71,7 +71,7 @@ parse_long_options (int argc,
             va_list authors;
             va_start (authors, usage_func);
             version_etc_va (stdout, command_name, package, version, authors);
-            exit (0);
+            exit (EXIT_SUCCESS);
           }
 
         default:
@@ -87,3 +87,59 @@ parse_long_options (int argc,
      the probably-new parameters when/if getopt is called later.  */
   optind = 0;
 }
+
+/* Process the GNU default long options --help and --version (see also
+   https://gnu.org/prep/standards/html_node/Command_002dLine-Interfaces.html),
+   and fail for any other unknown long or short option.
+   Use with SCAN_ALL=true to scan until "--", or with SCAN_ALL=false to stop
+   at the first non-option argument (or "--", whichever comes first).  */
+
+void
+parse_gnu_standard_options_only (int argc,
+                                 char **argv,
+                                 const char *command_name,
+                                 const char *package,
+                                 const char *version,
+                                 bool scan_all,
+                                 void (*usage_func) (int),
+                                 /* const char *author1, ...*/ ...)
+{
+  int c;
+  int saved_opterr;
+
+  saved_opterr = opterr;
+
+  /* Print an error message for unrecognized options.  */
+  opterr = 1;
+
+  const char *optstring = scan_all ? "" : "+";
+
+  if ((c = getopt_long (argc, argv, optstring, long_options, NULL)) != -1)
+    {
+      switch (c)
+        {
+        case 'h':
+          (*usage_func) (EXIT_SUCCESS);
+          break;
+
+        case 'v':
+          {
+            va_list authors;
+            va_start (authors, usage_func);
+            version_etc_va (stdout, command_name, package, version, authors);
+            exit (EXIT_SUCCESS);
+          }
+
+        default:
+          (*usage_func) (EXIT_FAILURE);
+          break;
+        }
+    }
+
+  /* Restore previous value.  */
+  opterr = saved_opterr;
+
+  /* Reset this to zero so that getopt internals get initialized from
+     the probably-new parameters when/if getopt is called later.  */
+  optind = 0;
+}
diff --git a/lib/long-options.h b/lib/long-options.h
index 109a20375..44d6aa6ab 100644
--- a/lib/long-options.h
+++ b/lib/long-options.h
@@ -17,6 +17,11 @@
 
 /* Written by Jim Meyering.  */
 
+#ifndef LONG_OPTIONS_H_
+# define LONG_OPTIONS_H_ 1
+
+# include <stdbool.h>
+
 void parse_long_options (int _argc,
                          char **_argv,
                          const char *_command_name,
@@ -24,3 +29,14 @@ void parse_long_options (int _argc,
                          const char *_version,
                          void (*_usage) (int),
                          /* const char *author1, ...*/ ...);
+
+void parse_gnu_standard_options_only (int argc,
+                                      char **argv,
+                                      const char *command_name,
+                                      const char *package,
+                                      const char *version,
+                                      bool scan_all,
+                                      void (*usage_func) (int),
+                                      /* const char *author1, ...*/ ...);
+
+#endif /* LONG_OPTIONS_H_ */
diff --git a/modules/long-options b/modules/long-options
index f1106c3cc..9bec13e75 100644
--- a/modules/long-options
+++ b/modules/long-options
@@ -7,6 +7,7 @@ lib/long-options.c
 
 Depends-on:
 getopt-gnu
+stdbool
 stdlib
 version-etc
 
-- 
2.19.1