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/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement: ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution.
* 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#define _DEFAULT_SOURCE
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <envlock.h>
/*
* setenv --
* Set the value of the environmental variable "name" to be
* "value". If rewrite is set, replace any current value.
*/
extern char **environ;
/* Only deal with a pointer to environ, to work around subtle bugs with shared
libraries and/or small data systems where the user declares his own
'environ'. */
static char ***p_environ = &environ;
int
setenv(const char *name, const char *value, int rewrite)
{
static int alloced; /* if allocated space before */
register char *C;
size_t l_value;
int offset;
/* Name cannot be NULL, empty, or contain an equal sign. */
if (name == NULL || name[0] == '\0' || strchr(name, '=')) {
errno = EINVAL;
return -1;
}
ENV_LOCK;
l_value = strlen(value);
if ((C = _findenv(name, &offset))) { /* find if already exists */
if (!rewrite) {
ENV_UNLOCK;
return 0;
}
if (strlen(C) >= l_value) { /* old larger; copy over */
strcpy(C, value);
ENV_UNLOCK;
return 0;
}
} else { /* create new slot */
register int cnt;
register char **P;
for (P = *p_environ, cnt = 0; *P; ++P, ++cnt)
;
if (alloced) { /* just increase size */
*p_environ = (char **)realloc((char *)environ, (size_t)(sizeof(char *) * (cnt + 2)));
if (!*p_environ) {
ENV_UNLOCK;
return -1;
}
} else { /* get new space */
alloced = 1; /* copy old entries into it */
P = (char **)malloc((size_t)(sizeof(char *) * (cnt + 2)));
if (!P) {
ENV_UNLOCK;
return (-1);
}
memcpy((char *)P, (char *)*p_environ, cnt * sizeof(char *));
*p_environ = P;
}
(*p_environ)[cnt + 1] = NULL;
offset = cnt;
}
for (C = (char *)name; *C && *C != '='; ++C)
; /* no `=' in name */
char *E = malloc((size_t)((int)(C - name) + l_value + 2));
if (!E) {
ENV_UNLOCK;
return -1;
}
(*p_environ)[offset] = E;
for (C = E; (*C = *name++) && *C != '='; ++C)
;
for (*C++ = '='; (*C++ = *value++) != 0;)
;
ENV_UNLOCK;
return 0;
}
/*
* unsetenv(name) --
* Delete environmental variable "name".
*/
int
unsetenv(const char *name)
{
register char **P;
int offset;
/* Name cannot be NULL, empty, or contain an equal sign. */
if (name == NULL || name[0] == '\0' || strchr(name, '=')) {
errno = EINVAL;
return -1;
}
ENV_LOCK;
while (_findenv(name, &offset)) /* if set multiple times */
{
for (P = &(*p_environ)[offset];; ++P)
if (!(*P = *(P + 1)))
break;
}
ENV_UNLOCK;
return 0;
}