cpython/Python/getopt.c

/*---------------------------------------------------------------------------*
 * <RCS keywords>
 *
 * C++ Library
 *
 * Copyright 1992-1994, David Gottner
 *
 *                    All Rights Reserved
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice, this permission notice and
 * the following disclaimer notice appear unmodified in all copies.
 *
 * I DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL I
 * BE LIABLE FOR ANY SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
 * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA, OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Nevertheless, I would like to know about bugs in this library or
 * suggestions for improvment.  Send bug reports and feedback to
 * davegottner@delphi.com.
 *---------------------------------------------------------------------------*/

/* Modified to support --help and --version, as well as /? on Windows
 * by Georg Brandl. */

#include <stdio.h>
#include <string.h>

#ifdef __cplusplus
extern "C" {
#endif

int _PyOS_opterr = 1;          /* generate error messages */
int _PyOS_optind = 1;          /* index into argv array   */
char *_PyOS_optarg = NULL;     /* optional argument       */

int _PyOS_GetOpt(int argc, char **argv, char *optstring)
{
    static char *opt_ptr = "";
    char *ptr;
    int option;

    if (*opt_ptr == '\0') {

        if (_PyOS_optind >= argc)
            return -1;
#ifdef MS_WINDOWS
        else if (strcmp(argv[_PyOS_optind], "/?") == 0) {
            ++_PyOS_optind;
            return 'h';
        }
#endif

        else if (argv[_PyOS_optind][0] != '-' ||
                 argv[_PyOS_optind][1] == '\0' /* lone dash */ )
            return -1;

        else if (strcmp(argv[_PyOS_optind], "--") == 0) {
            ++_PyOS_optind;
            return -1;
        }

        else if (strcmp(argv[_PyOS_optind], "--help") == 0) {
            ++_PyOS_optind;
            return 'h';
        }

        else if (strcmp(argv[_PyOS_optind], "--version") == 0) {
            ++_PyOS_optind;
            return 'V';
        }


        opt_ptr = &argv[_PyOS_optind++][1];
    }

    if ( (option = *opt_ptr++) == '\0')
        return -1;

    if (option == 'J') {
        fprintf(stderr, "-J is reserved for Jython\n");
        return '_';
    }

    if (option == 'X') {
        fprintf(stderr,
          "-X is reserved for implementation-specific arguments\n");
        return '_';
    }

    if ((ptr = strchr(optstring, option)) == NULL) {
        if (_PyOS_opterr)
            fprintf(stderr, "Unknown option: -%c\n", option);

        return '_';
    }

    if (*(ptr + 1) == ':') {
        if (*opt_ptr != '\0') {
            _PyOS_optarg  = opt_ptr;
            opt_ptr = "";
        }

        else {
            if (_PyOS_optind >= argc) {
                if (_PyOS_opterr)
                    fprintf(stderr,
                "Argument expected for the -%c option\n", option);
                return '_';
            }

            _PyOS_optarg = argv[_PyOS_optind++];
        }
    }

    return option;
}

#ifdef __cplusplus
}
#endif