4 files changed, 77 insertions, 0 deletions
diff --git a/lib/compat/Makemodule.am b/lib/compat/Makemodule.am
index f1bb2de..b7649ef 100644
--- a/lib/compat/Makemodule.am
+++ b/lib/compat/Makemodule.am
@@ -2,6 +2,7 @@ libcompat_a_SOURCES = lib/compat/getline.c lib/compat/getsubopt.c
 libcompat_a_SOURCES += lib/compat/strndup.c lib/compat/mockups.c
 libcompat_a_SOURCES += lib/compat/chdir.c include/compat.h
 libcompat_a_SOURCES += lib/compat/path_to_windows.c lib/compat/getopt.c
+libcompat_a_SOURCES += lib/compat/getopt_long.c
 
 noinst_LIBRARIES += libcompat.a
 
diff --git a/lib/compat/getopt_long.c b/lib/compat/getopt_long.c
new file mode 100644
index 0000000..24f5864
--- /dev/null
+++ b/lib/compat/getopt_long.c
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * getopt_long.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+#include "compat.h"
+
+#ifdef HAVE_GETOPT
+#include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+
+#ifndef HAVE_GETOPT_LONG
+int getopt_long(int argc, char *const argv[], const char *optstr,
+		const struct option *longopts, int *longindex)
+{
+	size_t i, len;
+	char *ptr;
+	(void)longindex;
+
+	if (optind >= argc || argv[optind][0] != '-' ||
+	    argv[optind][1] != '-' || argv[optind][2] == '\0')
+		return getopt(argc, argv, optstr);
+
+	optarg = NULL;
+	ptr = argv[optind] + 2;
+
+	for (len = 0; ptr[len] != '\0' && ptr[len] != '='; ++len)
+		;
+
+	for (i = 0; longopts[i].name != NULL; ++i) {
+		if (strncmp(longopts[i].name, ptr, len) != 0)
+			continue;
+
+		if (longopts[i].name[len] == '\0')
+			break;
+	}
+
+	if (longopts[i].name == NULL)
+		goto fail_unknown;
+
+	if (ptr[len] == '=') {
+		if (!longopts[i].has_arg)
+			goto fail_arg;
+
+		optarg = ptr + len + 1;
+	} else if (longopts[i].has_arg) {
+		if (++optind >= argc)
+			goto fail_no_arg;
+
+		optarg = argv[optind];
+	}
+
+	++optind;
+	return longopts[i].val;
+fail_unknown:
+	fprintf(stderr, "%s: unknown option `--%s`\n", argv[0], ptr);
+	return '?';
+fail_arg:
+	fprintf(stderr, "%s: no argument expected for option `--%s`\n",
+		argv[0], ptr);
+	return '?';
+fail_no_arg:
+	fprintf(stderr, "%s: missing argument for option `--%s`\n",
+		argv[0], ptr);
+	return '?';
+}
+#endif
diff --git a/lib/compat/libcompat.vcxproj b/lib/compat/libcompat.vcxproj
index 307754e..0dada12 100644
--- a/lib/compat/libcompat.vcxproj
+++ b/lib/compat/libcompat.vcxproj
@@ -157,6 +157,7 @@
     <ClCompile Include="chdir.c" />
     <ClCompile Include="getline.c" />
     <ClCompile Include="getopt.c" />
+    <ClCompile Include="getopt_long.c" />
     <ClCompile Include="getsubopt.c" />
     <ClCompile Include="mockups.c" />
     <ClCompile Include="path_to_windows.c" />
diff --git a/lib/compat/libcompat.vcxproj.filters b/lib/compat/libcompat.vcxproj.filters
index f2851d1..2eb9cfb 100644
--- a/lib/compat/libcompat.vcxproj.filters
+++ b/lib/compat/libcompat.vcxproj.filters
@@ -17,6 +17,9 @@
     <ClCompile Include="getopt.c">
       <Filter>Source</Filter>
     </ClCompile>
+    <ClCompile Include="getopt_long.c">
+      <Filter>Source</Filter>
+    </ClCompile>
     <ClCompile Include="getsubopt.c">
       <Filter>Source</Filter>
     </ClCompile>