cosmopolitan/third_party/getopt/getsubopt.c

/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8   -*-│
│ vi: set noet ft=c ts=8 sw=8 fenc=utf-8                                   :vi │
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│ Copyright (c) 1990, 1993                                                     │
│      The Regents of the University of California.  All rights reserved.      │
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│ Redistribution and use in source and binary forms, with or without           │
│ modification, are permitted provided that the following conditions           │
│ are met:                                                                     │
│  1. Redistributions of source code must retain the above copyright           │
│     notice, this list of conditions and the following disclaimer.            │
│  2. Redistributions in binary form must reproduce the above copyright        │
│     notice, this list of conditions and the following disclaimer in the      │
│     documentation and/or other materials provided with the distribution.     │
│  3. Neither the name of the University nor the names of its contributors     │
│     may be used to endorse or promote products derived from this software    │
│     without specific prior written permission.                               │
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│ THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND      │
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│ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL   │
│ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS      │
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│ SUCH DAMAGE.                                                                 │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/str.h"

/*
 * The SVID interface to getsubopt provides no way of figuring out which
 * part of the suboptions list wasn't matched.  This makes error messages
 * tricky...  The extern variable suboptarg is a pointer to the token
 * which didn't match.
 */
char *suboptarg;

int
getsubopt(char **optionp, char * const *tokens, char **valuep)
{
	int cnt;
	char *p;

	suboptarg = *valuep = NULL;

	/* skip leading white-space, commas */
	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);

	if (!*p) {
		*optionp = p;
		return(-1);
	}

	/* save the start of the token, and skip the rest of the token. */
	for (suboptarg = p;
	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);

	if (*p) {
		/*
		 * If there's an equals sign, set the value pointer, and
		 * skip over the value part of the token.  Terminate the
		 * token.
		 */
		if (*p == '=') {
			*p = '\0';
			for (*valuep = ++p;
			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
			if (*p) 
				*p++ = '\0';
		} else
			*p++ = '\0';
		/* Skip any whitespace or commas after this token. */
		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
	}

	/* set optionp for next round. */
	*optionp = p;

	for (cnt = 0; *tokens; ++tokens, ++cnt)
		if (!strcmp(suboptarg, *tokens))
			return(cnt);
	return(-1);
}