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/* $OpenBSD: setenv.c,v 1.9 2005/08/08 08:05:37 espie Exp $ */
/*
* Copyright (c) 1987 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 *offset);
extern char **environ;
/*
* setenv --
* Set the value of the environmental variable "name" to be
* "value". If rewrite is set, replace any current value.
*/
int
setenv(const char *name, const char *value, int rewrite)
{
static char **lastenv; /* last value of environ */
char *C;
int l_value, offset;
if (*value == '=') /* no `=' in value */
++value;
l_value = strlen(value);
if ((C = __findenv(name, &offset))) { /* find if already exists */
if (!rewrite)
return (0);
if ((int)strlen(C) >= l_value) { /* old larger; copy over */
while ((*C++ = *value++))
;
return (0);
}
} else { /* create new slot */
size_t cnt;
char **P;
for (P = environ; *P != NULL; P++)
;
cnt = P - environ;
P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
if (!P)
return (-1);
if (lastenv != environ)
memcpy(P, environ, cnt * sizeof(char *));
lastenv = environ = P;
offset = cnt;
environ[cnt + 1] = NULL;
}
for (C = (char *)name; *C && *C != '='; ++C)
; /* no `=' in name */
if (!(environ[offset] = /* name + `=' + value */
malloc((size_t)((int)(C - name) + l_value + 2))))
return (-1);
for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
;
for (*C++ = '='; (*C++ = *value++); )
;
return (0);
}
/*
* unsetenv(name) --
* Delete environmental variable "name".
*/
int
unsetenv(const char *name)
{
char **P;
int offset;
while (__findenv(name, &offset)) /* if set multiple times */
for (P = &environ[offset];; ++P)
if (!(*P = *(P + 1)))
break;
return 0;
}
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