230 lines
8.1 KiB
C
Executable file
230 lines
8.1 KiB
C
Executable file
/* Copyright (c) 2012, Kim Gräsman
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* * Neither the name of Kim Gräsman nor the names of contributors may be used
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* to endorse or promote products derived from this software without specific
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* prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL KIM GRÄSMAN BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "getopt.h"
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#include <stddef.h>
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#include <string.h>
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const int no_argument = 0;
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const int required_argument = 1;
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const int optional_argument = 2;
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char* optarg;
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int optopt;
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/* The variable optind [...] shall be initialized to 1 by the system. */
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int optind = 1;
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int opterr;
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static char* optcursor = NULL;
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/* Implemented based on [1] and [2] for optional arguments.
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optopt is handled FreeBSD-style, per [3].
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Other GNU and FreeBSD extensions are purely accidental.
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[1] http://pubs.opengroup.org/onlinepubs/000095399/functions/getopt.html
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[2] http://www.kernel.org/doc/man-pages/online/pages/man3/getopt.3.html
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[3] http://www.freebsd.org/cgi/man.cgi?query=getopt&sektion=3&manpath=FreeBSD+9.0-RELEASE
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*/
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int getopt(int argc, char* const argv[], const char* optstring) {
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int optchar = -1;
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const char* optdecl = NULL;
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optarg = NULL;
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opterr = 0;
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optopt = 0;
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/* Unspecified, but we need it to avoid overrunning the argv bounds. */
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if (optind >= argc)
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goto no_more_optchars;
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/* If, when getopt() is called argv[optind] is a null pointer, getopt()
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shall return -1 without changing optind. */
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if (argv[optind] == NULL)
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goto no_more_optchars;
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/* If, when getopt() is called *argv[optind] is not the character '-',
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getopt() shall return -1 without changing optind. */
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if (*argv[optind] != '-')
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goto no_more_optchars;
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/* If, when getopt() is called argv[optind] points to the string "-",
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getopt() shall return -1 without changing optind. */
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if (strcmp(argv[optind], "-") == 0)
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goto no_more_optchars;
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/* If, when getopt() is called argv[optind] points to the string "--",
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getopt() shall return -1 after incrementing optind. */
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if (strcmp(argv[optind], "--") == 0) {
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++optind;
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goto no_more_optchars;
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}
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if (optcursor == NULL || *optcursor == '\0')
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optcursor = argv[optind] + 1;
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optchar = *optcursor;
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/* FreeBSD: The variable optopt saves the last known option character
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returned by getopt(). */
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optopt = optchar;
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/* The getopt() function shall return the next option character (if one is
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found) from argv that matches a character in optstring, if there is
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one that matches. */
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optdecl = strchr(optstring, optchar);
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if (optdecl) {
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/* [I]f a character is followed by a colon, the option takes an
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argument. */
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if (optdecl[1] == ':') {
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optarg = ++optcursor;
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if (*optarg == '\0') {
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/* GNU extension: Two colons mean an option takes an
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optional arg; if there is text in the current argv-element
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(i.e., in the same word as the option name itself, for example,
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"-oarg"), then it is returned in optarg, otherwise optarg is set
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to zero. */
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if (optdecl[2] != ':') {
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/* If the option was the last character in the string pointed to by
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an element of argv, then optarg shall contain the next element
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of argv, and optind shall be incremented by 2. If the resulting
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value of optind is greater than argc, this indicates a missing
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option-argument, and getopt() shall return an error indication.
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Otherwise, optarg shall point to the string following the
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option character in that element of argv, and optind shall be
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incremented by 1.
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*/
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if (++optind < argc) {
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optarg = argv[optind];
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} else {
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/* If it detects a missing option-argument, it shall return the
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colon character ( ':' ) if the first character of optstring
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was a colon, or a question-mark character ( '?' ) otherwise.
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*/
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optarg = NULL;
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optchar = (optstring[0] == ':') ? ':' : '?';
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}
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} else {
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optarg = NULL;
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}
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}
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optcursor = NULL;
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}
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} else {
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/* If getopt() encounters an option character that is not contained in
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optstring, it shall return the question-mark ( '?' ) character. */
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optchar = '?';
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}
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if (optcursor == NULL || *++optcursor == '\0')
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++optind;
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return optchar;
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no_more_optchars:
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optcursor = NULL;
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return -1;
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}
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/* Implementation based on [1].
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[1] http://www.kernel.org/doc/man-pages/online/pages/man3/getopt.3.html
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*/
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int getopt_long(int argc, char* const argv[], const char* optstring,
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const struct option* longopts, int* longindex) {
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const struct option* o = longopts;
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const struct option* match = NULL;
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int num_matches = 0;
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size_t argument_name_length = 0;
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const char* current_argument = NULL;
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int retval = -1;
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optarg = NULL;
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optopt = 0;
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if (optind >= argc)
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return -1;
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if (strlen(argv[optind]) < 3 || strncmp(argv[optind], "--", 2) != 0)
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return getopt(argc, argv, optstring);
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/* It's an option; starts with -- and is longer than two chars. */
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current_argument = argv[optind] + 2;
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argument_name_length = strcspn(current_argument, "=");
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for (; o->name; ++o) {
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if (strncmp(o->name, current_argument, argument_name_length) == 0) {
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match = o;
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++num_matches;
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}
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}
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if (num_matches == 1) {
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/* If longindex is not NULL, it points to a variable which is set to the
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index of the long option relative to longopts. */
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if (longindex)
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*longindex = (int) (match - longopts);
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/* If flag is NULL, then getopt_long() shall return val.
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Otherwise, getopt_long() returns 0, and flag shall point to a variable
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which shall be set to val if the option is found, but left unchanged if
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the option is not found. */
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if (match->flag)
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*(match->flag) = match->val;
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retval = match->flag ? 0 : match->val;
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if (match->has_arg != no_argument) {
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optarg = strchr(argv[optind], '=');
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if (optarg != NULL)
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++optarg;
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if (match->has_arg == required_argument) {
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/* Only scan the next argv for required arguments. Behavior is not
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specified, but has been observed with Ubuntu and Mac OSX. */
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if (optarg == NULL && ++optind < argc) {
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optarg = argv[optind];
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}
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if (optarg == NULL)
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retval = ':';
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}
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} else if (strchr(argv[optind], '=')) {
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/* An argument was provided to a non-argument option.
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I haven't seen this specified explicitly, but both GNU and BSD-based
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implementations show this behavior.
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*/
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retval = '?';
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}
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} else {
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/* Unknown option or ambiguous match. */
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retval = '?';
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}
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++optind;
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return retval;
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}
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