setenv.c revision 5c526acb82c882e41b655c31f5fa4425c87b671c
#ifndef lint
static char *rcsid = "$Id: setenv.c,v 1.1 2003/06/04 00:27:01 marka Exp $";
#endif
/*
* Copyright (c) 2002 Japan Network Information Center.
* All rights reserved.
*
* By using this file, you agree to the terms and conditions set forth bellow.
*
* LICENSE TERMS AND CONDITIONS
*
* The following License Terms and Conditions apply, unless a different
* license is obtained from Japan Network Information Center ("JPNIC"),
* a Japanese association, Kokusai-Kougyou-Kanda Bldg 6F, 2-3-4 Uchi-Kanda,
* Chiyoda-ku, Tokyo 101-0047, Japan.
*
* 1. Use, Modification and Redistribution (including distribution of any
* modified or derived work) in source and/or binary forms is permitted
* under this License Terms and Conditions.
*
* 2. Redistribution of source code must retain the copyright notices as they
* appear in each source code file, this License Terms and Conditions.
*
* 3. Redistribution in binary form must reproduce the Copyright Notice,
* this License Terms and Conditions, in the documentation and/or other
* materials provided with the distribution. For the purposes of binary
* distribution the "Copyright Notice" refers to the following language:
* "Copyright (c) 2000-2002 Japan Network Information Center. All rights reserved."
*
* 4. The name of JPNIC may not be used to endorse or promote products
* derived from this Software without specific prior written approval of
* JPNIC.
*
* 5. Disclaimer/Limitation of Liability: THIS SOFTWARE IS PROVIDED BY JPNIC
* "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 JPNIC 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 DAMAGES.
*/
#include <stddef.h>
#include <string.h>
/*
* We don't include <stdlib.h> here.
* Also <stdlib.h> may declare `environ' and its type might be different
* from ours.
*/
extern char **environ;
typedef struct myenv myenv_t;
struct myenv {
char *pointer;
myenv_t *next;
myenv_t *prev;
};
static myenv_t *myenvs = NULL;
void
myunsetenv(const char *name) {
char **e;
myenv_t *mye;
size_t namelen;
extern void free(void *);
namelen = strlen(name);
for (e = environ; *e != NULL; e++) {
if (strncmp(*e, name, namelen) == 0 && (*e)[namelen] == '=')
break;
}
if (*e == NULL)
return;
for (mye = myenvs; mye != NULL; mye = mye->next) {
if (mye->pointer == *e) {
if (mye->next != NULL)
mye->next->prev = mye->prev;
if (mye->prev != NULL)
mye->prev->next = mye->next;
if (mye->next == NULL && mye->prev == NULL)
myenvs = NULL;
free(mye);
free(*e);
break;
}
}
for ( ; *e != NULL; e++)
*e = *(e + 1);
}
#include <stdlib.h>
int
mysetenv(const char *name, const char *value, int overwrite) {
myenv_t *mye;
char *buffer;
int result;
if (getenv(name) != NULL && !overwrite)
return 0;
buffer = (char *) malloc(strlen(name) + strlen(value) + 2);
if (buffer == NULL)
return -1;
strcpy(buffer, name);
strcat(buffer, "=");
strcat(buffer, value);
myunsetenv(name);
mye = (myenv_t *) malloc(sizeof(myenv_t));
if (mye == NULL)
return -1;
mye->pointer = buffer;
mye->next = myenvs;
mye->prev = NULL;
if (myenvs != NULL)
myenvs->prev = mye;
myenvs = mye;
result = putenv(buffer);
return result;
}