getopt.c

// SPDX-License-Identifier: MIT

#include "dr.h"

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

#define flockfile(f)
#define funlockfile(f)
#define required_argument  1
#define optarg dr_optarg
#define optind dr_optind
#define opterr dr_opterr
#define optopt dr_optopt
#define __optpos dr_optpos
#define optpos dr_optpos
#define __optreset dr_optreset
#define option dr_option
#define getopt(argc, argv, optstring) dr_getopt(argc, argv, optstring)
#define getopt_long(argc, argv, optstring, longopts, idx) dr_getopt_long(argc, argv, optstring, longopts, idx)
#define __lctrans_cur(msg) (msg)

// Derived from https://git.musl-libc.org/cgit/musl/tree/src/misc/getopt.c?h=v1.1.18
// Released under a MIT license, see COPYRIGHT.musl

char *restrict optarg;
int optind=1, opterr=1, optopt, __optpos, __optreset=0;

static void __getopt_msg(const char *a, const char *b, const char *c, size_t l)
{
	b = __lctrans_cur(b);
	const struct dr_result_size r = dr_fprintf(&dr_stderr.ih.io, "%s%*s%c\n", a, (int)l, b, *c);
	(void)r;
}

int getopt(int argc, char * const argv[], const char *optstring)
{
	int i;
	wchar_t c, d;
	int k, l;
	char *optchar;

	if (!optind || __optreset) {
		__optreset = 0;
		__optpos = 0;
		optind = 1;
	}

	if (optind >= argc || !argv[optind])
		return -1;

	if (argv[optind][0] != '-') {
		if (optstring[0] == '-') {
			optarg = argv[optind++];
			return 1;
		}
		return -1;
	}

	if (!argv[optind][1])
		return -1;

	if (argv[optind][1] == '-' && !argv[optind][2])
		return optind++, -1;

	if (!optpos) optpos++;
	if ((k = mbtowc(&c, argv[optind]+optpos, MB_LEN_MAX)) < 0) {
		k = 1;
		c = 0xfffd; /* replacement char */
	}
	optchar = argv[optind]+optpos;
	optpos += k;

	if (!argv[optind][optpos]) {
		optind++;
		optpos = 0;
	}

	if (optstring[0] == '-' || optstring[0] == '+')
		optstring++;

	i = 0;
	d = 0;
	do {
		l = mbtowc(&d, optstring+i, MB_LEN_MAX);
		if (l>0) i+=l; else i++;
	} while (l && d != c);

	if (d != c || c == ':') {
		optopt = c;
		if (optstring[0] != ':' && opterr)
			__getopt_msg(argv[0], ": unrecognized option: ", optchar, k);
		return '?';
	}
	if (optstring[i] == ':') {
		if (optstring[i+1] == ':') optarg = 0;
		else if (optind >= argc) {
			optopt = c;
			if (optstring[0] == ':') return ':';
			if (opterr) __getopt_msg(argv[0],
				": option requires an argument: ",
				optchar, k);
			return '?';
		}
		if (optstring[i+1] != ':' || optpos) {
			optarg = argv[optind++] + optpos;
			optpos = 0;
		}
	}
	return c;
}

// Derived from https://git.musl-libc.org/cgit/musl/tree/src/misc/getopt.c?h=v1.1.18
// Released under a MIT license, see COPYRIGHT.musl

static void permute(char **argv, int dest, int src)
{
	char **av = argv;
	char *tmp = av[src];
	int i;
	for (i=src; i>dest; i--)
		av[i] = av[i-1];
	av[dest] = tmp;
}

static int __getopt_long_core(int argc, char *const *argv, const char *optstring, const struct option *longopts, int *idx, int longonly);

static int __getopt_long(int argc, char **argv, const char *optstring, const struct option *longopts, int *idx, int longonly)
{
	int ret, skipped, resumed;
	if (!optind || __optreset) {
		__optreset = 0;
		__optpos = 0;
		optind = 1;
	}
	if (optind >= argc || !argv[optind]) return -1;
	skipped = optind;
	if (optstring[0] != '+' && optstring[0] != '-') {
		int i;
		for (i=optind; ; i++) {
			if (i >= argc || !argv[i]) return -1;
			if (argv[i][0] == '-' && argv[i][1]) break;
		}
		optind = i;
	}
	resumed = optind;
	ret = __getopt_long_core(argc, argv, optstring, longopts, idx, longonly);
	if (resumed > skipped) {
		int i, cnt = optind-resumed;
		for (i=0; i<cnt; i++)
			permute(argv, skipped, optind-1);
		optind = skipped + cnt;
	}
	return ret;
}

static int __getopt_long_core(int argc, char *const *argv, const char *optstring, const struct option *longopts, int *idx, int longonly)
{
	optarg = 0;
	if (longopts && argv[optind][0] == '-' &&
		((longonly && argv[optind][1] && argv[optind][1] != '-') ||
		 (argv[optind][1] == '-' && argv[optind][2])))
	{
		int colon = optstring[optstring[0]=='+'||optstring[0]=='-']==':';
		int i, cnt, match;
		char *arg, *opt;
		for (cnt=i=0; longopts[i].name; i++) {
			const char *name = longopts[i].name;
			opt = argv[optind]+1;
			if (*opt == '-') opt++;
			while (*opt && *opt != '=' && *opt == *name)
				name++, opt++;
			if (*opt && *opt != '=') continue;
			arg = opt;
			match = i;
			if (!*name) {
				cnt = 1;
				break;
			}
			cnt++;
		}
		if (cnt==1) {
			i = match;
			opt = arg;
			optind++;
			if (*opt == '=') {
				if (!longopts[i].has_arg) {
					optopt = longopts[i].val;
					if (colon || !opterr)
						return '?';
					__getopt_msg(argv[0],
						": option does not take an argument: ",
						longopts[i].name,
						strlen(longopts[i].name));
					return '?';
				}
				optarg = opt+1;
			} else if (longopts[i].has_arg == required_argument) {
				if (!(optarg = argv[optind])) {
					optopt = longopts[i].val;
					if (colon) return ':';
					if (!opterr) return '?';
					__getopt_msg(argv[0],
						": option requires an argument: ",
						longopts[i].name,
						strlen(longopts[i].name));
					return '?';
				}
				optind++;
			}
			if (idx) *idx = i;
			if (longopts[i].flag) {
				*longopts[i].flag = longopts[i].val;
				return 0;
			}
			return longopts[i].val;
		}
		if (argv[optind][1] == '-') {
			optopt = 0;
			if (!colon && opterr)
				__getopt_msg(argv[0], cnt ?
					": option is ambiguous: " :
					": unrecognized option: ",
					argv[optind]+2,
					strlen(argv[optind]+2));
			optind++;
			return '?';
		}
	}
	return getopt(argc, argv, optstring);
}

int getopt_long(int argc, char **argv, const char *optstring, const struct option *longopts, int *idx)
{
	return __getopt_long(argc, argv, optstring, longopts, idx, 0);
}

#undef flockfile
#undef funlockfile
#undef required_argument
#undef optarg
#undef optind
#undef opterr
#undef optopt
#undef __optpos
#undef optpos
#undef __optreset
#undef option
#undef getopt
#undef getopt_long
#undef __lctrans_cur