minetest-mapper-cpp/Minetestmapper/ketopt.h

#pragma once

/*
	This File was taken from https://github.com/attractivechaos/klib/blob/master/ketopt.h and is licensed under MIT license.


Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#include <string.h> /* for strchr() and strncmp() */

#define ko_no_argument       0
#define ko_required_argument 1
#define ko_optional_argument 2

typedef struct {
	int ind;   /* equivalent to optind */
	int opt;   /* equivalent to optopt */
	char *arg; /* equivalent to optarg */
	int longidx; /* index of a long option; or -1 if short */
	/* private variables not intended for external uses */
	int i, pos, n_args;
} ketopt_t;

typedef struct {
	const char *name;
	int has_arg;
	int val;
} ko_longopt_t;

static ketopt_t KETOPT_INIT = { 1, 0, 0, -1, 1, 0, 0 };

static void ketopt_permute(char *argv[], int j, int n) /* move argv[j] over n elements to the left */
{
	int k;
	char *p = argv[j];
	for (k = 0; k < n; ++k)
		argv[j - k] = argv[j - k - 1];
	argv[j - k] = p;
}

/**
 * Parse command-line options and arguments
 *
 * This fuction has a similar interface to GNU's getopt_long(). Each call
 * parses one option and returns the option name.  s->arg points to the option
 * argument if present. The function returns -1 when all command-line arguments
 * are parsed. In this case, s->ind is the index of the first non-option
 * argument.
 *
 * @param s         status; shall be initialized to KETOPT_INIT on the first call
 * @param argc      length of argv[]
 * @param argv      list of command-line arguments; argv[0] is ignored
 * @param permute   non-zero to move options ahead of non-option arguments
 * @param ostr      option string
 * @param longopts  long options
 *
 * @return ASCII for a short option; ko_longopt_t::val for a long option; -1 if
 *         argv[] is fully processed; '?' for an unknown option or an ambiguous
 *         long option; ':' if an option argument is missing
 */
static int ketopt(ketopt_t *s, int argc, char *argv[], int permute, const char *ostr, const ko_longopt_t *longopts)
{
	int opt = -1, i0, j;
	if (permute) {
		while (s->i < argc && (argv[s->i][0] != '-' || argv[s->i][1] == '\0'))
			++s->i, ++s->n_args;
	}
	s->arg = 0, s->longidx = -1, i0 = s->i;
	if (s->i >= argc || argv[s->i][0] != '-' || argv[s->i][1] == '\0') {
		s->ind = s->i - s->n_args;
		return -1;
	}
	if (argv[s->i][0] == '-' && argv[s->i][1] == '-') { /* "--" or a long option */
		if (argv[s->i][2] == '\0') { /* a bare "--" */
			ketopt_permute(argv, s->i, s->n_args);
			++s->i, s->ind = s->i - s->n_args;
			return -1;
		}
		s->opt = 0, opt = '?', s->pos = -1;
		if (longopts) { /* parse long options */
			int k, n_matches = 0;
			const ko_longopt_t *o = 0;
			for (j = 2; argv[s->i][j] != '\0' && argv[s->i][j] != '='; ++j) {} /* find the end of the option name */
			for (k = 0; longopts[k].name != 0; ++k)
				if (strncmp(&argv[s->i][2], longopts[k].name, j - 2) == 0)
					++n_matches, o = &longopts[k];
			if (n_matches == 1) {
				s->opt = opt = o->val, s->longidx = (int)(o - longopts);
				if (argv[s->i][j] == '=') s->arg = &argv[s->i][j + 1];
				if (o->has_arg == 1 && argv[s->i][j] == '\0') {
					if (s->i < argc - 1) s->arg = argv[++s->i];
					else opt = ':'; /* missing option argument */
				}
			}
		}
	}
	else { /* a short option */
		const char *p;
		if (s->pos == 0) s->pos = 1;
		opt = s->opt = argv[s->i][s->pos++];
		p = strchr(ostr, opt);
		if (p == 0) {
			opt = '?'; /* unknown option */
		}
		else if (p[1] == ':') {
			if (argv[s->i][s->pos] == 0) {
				if (s->i < argc - 1) s->arg = argv[++s->i];
				else opt = ':'; /* missing option argument */
			}
			else s->arg = &argv[s->i][s->pos];
			s->pos = -1;
		}
	}
	if (s->pos < 0 || argv[s->i][s->pos] == 0) {
		++s->i, s->pos = 0;
		if (s->n_args > 0) /* permute */
			for (j = i0; j < s->i; ++j)
				ketopt_permute(argv, j, s->n_args);
	}
	s->ind = s->i - s->n_args;
	return opt;
}