xenocara/app/xedit/lisp/getenv.c
2013-01-14 22:05:51 +00:00

82 lines
2.8 KiB
C

/* $OpenBSD: getenv.c,v 1.1 2013/01/14 22:05:52 matthieu Exp $ */
/*
* Copyright (c) 1987, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <stdlib.h>
#include <string.h>
char *__findenv(const char *name, int len, int *offset);
/*
* __findenv --
* Returns pointer to value associated with name, if any, else NULL.
* Starts searching within the environmental array at offset.
* Sets offset to be the offset of the name/value combination in the
* environmental array, for use by putenv(3), setenv(3) and unsetenv(3).
* Explicitly removes '=' in argument name.
*
* This routine *should* be a static; don't use it.
*/
char *
__findenv(const char *name, int len, int *offset)
{
extern char **environ;
int i;
const char *np;
char **p, *cp;
if (name == NULL || environ == NULL)
return (NULL);
for (p = environ + *offset; (cp = *p) != NULL; ++p) {
for (np = name, i = len; i && *cp; i--)
if (*cp++ != *np++)
break;
if (i == 0 && *cp++ == '=') {
*offset = p - environ;
return (cp);
}
}
return (NULL);
}
/*
* getenv --
* Returns ptr to value associated with name, if any, else NULL.
*/
char *
getenv(const char *name)
{
int offset = 0;
const char *np;
for (np = name; *np && *np != '='; ++np)
;
return (__findenv(name, (int)(np - name), &offset));
}