args.c

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */


#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "args.h"

#ifdef _MSC_VER
#define snprintf _snprintf
#endif

#if defined(__GNUC__) && __GNUC__
extern void die(const char *fmt, ...) __attribute__((noreturn));
#else
extern void die(const char *fmt, ...);
#endif


struct arg arg_init(char **argv) {
  struct arg a;

  a.argv      = argv;
  a.argv_step = 1;
  a.name      = NULL;
  a.val       = NULL;
  a.def       = NULL;
  return a;
}

int arg_match(struct arg *arg_, const struct arg_def *def, char **argv) {
  struct arg arg;

  if (!argv[0] || argv[0][0] != '-')
    return 0;

  arg = arg_init(argv);

  if (def->short_name
      && strlen(arg.argv[0]) == strlen(def->short_name) + 1
      && !strcmp(arg.argv[0] + 1, def->short_name)) {

    arg.name = arg.argv[0] + 1;
    arg.val = def->has_val ? arg.argv[1] : NULL;
    arg.argv_step = def->has_val ? 2 : 1;
  } else if (def->long_name) {
    const size_t name_len = strlen(def->long_name);

    if (strlen(arg.argv[0]) >= name_len + 2
        && arg.argv[0][1] == '-'
        && !strncmp(arg.argv[0] + 2, def->long_name, name_len)
        && (arg.argv[0][name_len + 2] == '='
            || arg.argv[0][name_len + 2] == '\0')) {

      arg.name = arg.argv[0] + 2;
      arg.val = arg.name[name_len] == '=' ? arg.name + name_len + 1 : NULL;
      arg.argv_step = 1;
    }
  }

  if (arg.name && !arg.val && def->has_val)
    die("Error: option %s requires argument.\n", arg.name);