getopt.h

  1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
  2/*
  3 * getopt function definitions for NOLIBC, adapted from musl libc
  4 * Copyright (C) 2005-2020 Rich Felker, et al.
  5 * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
  6 */
  7
  8/* make sure to include all global symbols */
  9#include "nolibc.h"
 10
 11#ifndef _NOLIBC_GETOPT_H
 12#define _NOLIBC_GETOPT_H
 13
 14struct FILE;
 15static struct FILE *const stderr;
 16static int fprintf(struct FILE *stream, const char *fmt, ...);
 17
 18__attribute__((weak,unused,section(".data.nolibc_getopt")))
 19char *optarg;
 20
 21__attribute__((weak,unused,section(".data.nolibc_getopt")))
 22int optind = 1, opterr = 1, optopt;
 23
 24static __attribute__((unused))
 25int getopt(int argc, char * const argv[], const char *optstring)
 26{
 27	static int __optpos;
 28	int i;
 29	char c, d;
 30	char *optchar;
 31
 32	if (!optind) {
 33		__optpos = 0;
 34		optind = 1;
 35	}
 36
 37	if (optind >= argc || !argv[optind])
 38		return -1;
 39
 40	if (argv[optind][0] != '-') {
 41		if (optstring[0] == '-') {
 42			optarg = argv[optind++];
 43			return 1;
 44		}
 45		return -1;
 46	}
 47
 48	if (!argv[optind][1])
 49		return -1;
 50
 51	if (argv[optind][1] == '-' && !argv[optind][2])
 52		return optind++, -1;
 53
 54	if (!__optpos)
 55		__optpos++;
 56	c = argv[optind][__optpos];
 57	optchar = argv[optind] + __optpos;
 58	__optpos++;
 59
 60	if (!argv[optind][__optpos]) {
 61		optind++;
 62		__optpos = 0;
 63	}
 64
 65	if (optstring[0] == '-' || optstring[0] == '+')
 66		optstring++;
 67
 68	i = 0;
 69	d = 0;
 70	do {
 71		d = optstring[i++];
 72	} while (d && d != c);
 73
 74	if (d != c || c == ':') {
 75		optopt = c;
 76		if (optstring[0] != ':' && opterr)
 77			fprintf(stderr, "%s: unrecognized option: %c\n", argv[0], *optchar);
 78		return '?';
 79	}
 80	if (optstring[i] == ':') {
 81		optarg = NULL;
 82		if (optstring[i + 1] != ':' || __optpos) {
 83			optarg = argv[optind++];
 84			if (__optpos)
 85				optarg += __optpos;
 86			__optpos = 0;
 87		}
 88		if (optind > argc) {
 89			optopt = c;
 90			if (optstring[0] == ':')
 91				return ':';
 92			if (opterr)
 93				fprintf(stderr, "%s: option requires argument: %c\n",
 94					argv[0], *optchar);
 95			return '?';
 96		}
 97	}
 98	return c;
 99}
100
101#endif /* _NOLIBC_GETOPT_H */