usr/klibc/getopt.c

/*
 * getopt.c
 *
 * Simple POSIX getopt(), no GNU extensions...
 */

#include <stdint.h>
#include <unistd.h>
#include <string.h>

char *optarg;
int optind, opterr, optopt;
static struct getopt_private_state {
	const char *optptr;
	const char *last_optstring;
	char *const *last_argv;
} pvt;

int getopt(int argc, char *const *argv, const char *optstring)
{
	const char *carg;
	const char *osptr;
	int opt;

	/* getopt() relies on a number of different global state
	   variables, which can make this really confusing if there is
	   more than one use of getopt() in the same program.  This
	   attempts to detect that situation by detecting if the
	   "optstring" or "argv" argument have changed since last time
	   we were called; if so, reinitialize the query state. */

	if (optstring != pvt.last_optstring || argv != pvt.last_argv ||
	    optind < 1 || optind > argc) {
		/* optind doesn't match the current query */
		pvt.last_optstring = optstring;
		pvt.last_argv = argv;
		optind = 1;
		pvt.optptr = NULL;
	}

	carg = argv[optind];

	/* First, eliminate all non-option cases */

	if (!carg || carg[0] != '-' || !carg[1]) {
		return -1;
	}

	if (carg[1] == '-' && !carg[2]) {
		optind++;
		return -1;
	}

	if ((uintptr_t) (pvt.optptr - carg) > (uintptr_t) strlen(carg)) {
		/* Someone frobbed optind, change to new opt. */
		pvt.optptr = carg + 1;
	}

	opt = *pvt.optptr++;

	if (opt != ':' && (osptr = strchr(optstring, opt))) {
		if (osptr[1] == ':') {
			if (*pvt.optptr) {
				/* Argument-taking option with attached
				   argument */
				optarg = (char *)pvt.optptr;
				optind++;
			} else {
				/* Argument-taking option with non-attached
				   argument */
				if (argv[optind + 1]) {
					optarg = (char *)argv[optind+1];
					optind += 2;
				} else {
					/* Missing argument */
					optind++;
					return (optstring[0] == ':')
						? ':' : '?';
				}
			}
			return opt;
		} else {
			/* Non-argument-taking option */
			/* pvt.optptr will remember the exact position to
			   resume at */
			if (!*pvt.optptr)
				optind++;
			return opt;
		}
	} else {
		/* Unknown option */
		optopt = opt;
		if (!*pvt.optptr)
			optind++;
		return '?';
	}
}
1	/*
2	* getopt.c
3	*
4	* Simple POSIX getopt(), no GNU extensions...
5	*/
6
7	#include <stdint.h>
8	#include <unistd.h>
9	#include <string.h>
10
11	char *optarg;
12	int optind, opterr, optopt;
13	static struct getopt_private_state {
14	const char *optptr;
15	const char *last_optstring;
16	char const last_argv;
17	} pvt;
18
19	int getopt(int argc, char const argv, const char *optstring)
20	{
21	const char *carg;
22	const char *osptr;
23	int opt;
24
25	/* getopt() relies on a number of different global state
26	variables, which can make this really confusing if there is
27	more than one use of getopt() in the same program. This
28	attempts to detect that situation by detecting if the
29	"optstring" or "argv" argument have changed since last time
30	we were called; if so, reinitialize the query state. */
31
32	if (optstring != pvt.last_optstring \|\| argv != pvt.last_argv \|\|
33	optind < 1 \|\| optind > argc) {
34	/* optind doesn't match the current query */
35	pvt.last_optstring = optstring;
36	pvt.last_argv = argv;
37	optind = 1;
38	pvt.optptr = NULL;
39	}
40
41	carg = argv[optind];
42
43	/* First, eliminate all non-option cases */
44
45	if (!carg \|\| carg[0] != '-' \|\| !carg[1]) {
46	return -1;
47	}
48
49	if (carg[1] == '-' && !carg[2]) {
50	optind++;
51	return -1;
52	}
53
54	if ((uintptr_t) (pvt.optptr - carg) > (uintptr_t) strlen(carg)) {
55	/* Someone frobbed optind, change to new opt. */
56	pvt.optptr = carg + 1;
57	}
58
59	opt = *pvt.optptr++;
60
61	if (opt != ':' && (osptr = strchr(optstring, opt))) {
62	if (osptr[1] == ':') {
63	if (*pvt.optptr) {
64	/* Argument-taking option with attached
65	argument */
66	optarg = (char *)pvt.optptr;
67	optind++;
68	} else {
69	/* Argument-taking option with non-attached
70	argument */
71	if (argv[optind + 1]) {
72	optarg = (char *)argv[optind+1];
73	optind += 2;
74	} else {
75	/* Missing argument */
76	optind++;
77	return (optstring[0] == ':')
78	? ':' : '?';
79	}
80	}
81	return opt;
82	} else {
83	/* Non-argument-taking option */
84	/* pvt.optptr will remember the exact position to
85	resume at */
86	if (!*pvt.optptr)
87	optind++;
88	return opt;
89	}
90	} else {
91	/* Unknown option */
92	optopt = opt;
93	if (!*pvt.optptr)
94	optind++;
95	return '?';
96	}
97	}