libc: implement getopt_long partially

only the short option is supported now

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

include/getopt.h

@@ -0,0 +1,76 @@
+/****************************************************************************
+ * include/getopt.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_GETOPT_H
+#define __INCLUDE_GETOPT_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <unistd.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define no_argument             0
+#define required_argument       1
+#define optional_argument       2
+
+/****************************************************************************
+ * Public Type Definitions
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+struct option
+{
+  FAR const char *name;
+  int has_arg;
+  FAR int *flag;
+  int val;
+};
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+int getopt_long(int argc, FAR char *const argv[],
+                FAR const char *shortopts,
+                FAR const struct option *longopts,
+                FAR int *longind);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __INCLUDE_GETOPT_H */

libs/libc/unistd/lib_getopt.c

@@ -40,7 +40,7 @@
 #include <nuttx/config.h>
 
 #include <stdbool.h>
-#include <unistd.h>
+#include <getopt.h>
 #include <string.h>
 
 /****************************************************************************
@@ -294,3 +294,11 @@ int getopt(int argc, FAR char * const argv[], FAR const char *optstring)
   g_binitialized = false;
   return ERROR;
 }
+
+int getopt_long(int argc, FAR char *const argv[],
+                FAR const char *shortopts,
+                FAR const struct option *longopts,
+                FAR int *longind)
+{
+  return getopt(argc, argv, shortopts);
+}