159 lines
4.8 KiB
C
Executable file
159 lines
4.8 KiB
C
Executable file
/*
|
|
* 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. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. 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.
|
|
*/
|
|
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
static char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93";
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <errno.h>
|
|
#include <stddef.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
char *__findenv(const char *, int *);
|
|
|
|
/*
|
|
* setenv --
|
|
* Set the value of the environmental variable "name" to be
|
|
* "value". If rewrite is set, replace any current value.
|
|
*/
|
|
setenv(name, value, rewrite)
|
|
register const char *name;
|
|
register const char *value;
|
|
int rewrite;
|
|
{
|
|
extern char **environ;
|
|
static int alloced; /* if allocated space before */
|
|
register 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 (strlen(c) >= l_value) { /* old larger; copy over */
|
|
while (*c++ = *value++);
|
|
return (0);
|
|
}
|
|
} else { /* create new slot */
|
|
register int cnt;
|
|
register char **p;
|
|
|
|
for (p = environ, cnt = 0; *p; ++p, ++cnt);
|
|
if (alloced) { /* just increase size */
|
|
environ = (char **)realloc((char *)environ,
|
|
(size_t)(sizeof(char *) * (cnt + 2)));
|
|
if (!environ)
|
|
return (-1);
|
|
}
|
|
else { /* get new space */
|
|
alloced = 1; /* copy old entries into it */
|
|
p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
|
|
if (!p)
|
|
return (-1);
|
|
memcpy(p, environ, cnt * sizeof(char *));
|
|
environ = p;
|
|
}
|
|
environ[cnt + 1] = NULL;
|
|
offset = cnt;
|
|
}
|
|
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(name)
|
|
const char *name;
|
|
{
|
|
extern char **environ;
|
|
register char **p;
|
|
int offset;
|
|
|
|
if (name == NULL || strlen(name) == 0 || strchr(name, '=') != 0)
|
|
{
|
|
errno= EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
while (__findenv(name, &offset)) /* if set multiple times */
|
|
for (p = &environ[offset];; ++p)
|
|
if (!(*p = *(p + 1)))
|
|
break;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* __findenv --
|
|
* Returns pointer to value associated with name, if any, else NULL.
|
|
* Sets offset to be the offset of the name/value combination in the
|
|
* environmental array, for use by setenv(3) and unsetenv(3).
|
|
* Explicitly removes '=' in argument name.
|
|
*
|
|
* This routine *should* be a static; don't use it.
|
|
*/
|
|
char *
|
|
__findenv(name, offset)
|
|
register const char *name;
|
|
int *offset;
|
|
{
|
|
extern char **environ;
|
|
register int len;
|
|
register const char *np;
|
|
register char **p, *c;
|
|
|
|
if (name == NULL || environ == NULL)
|
|
return (NULL);
|
|
for (np = name; *np && *np != '='; ++np)
|
|
continue;
|
|
len = np - name;
|
|
for (p = environ; (c = *p) != NULL; ++p)
|
|
if (strncmp(c, name, len) == 0 && c[len] == '=') {
|
|
*offset = p - environ;
|
|
return (c + len + 1);
|
|
}
|
|
return (NULL);
|
|
}
|
|
/*
|
|
* $PchId: setenv.c,v 1.3 1996/05/09 20:43:02 philip Exp philip $
|
|
*/
|