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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
* and in all advertising materials mentioning features or use of this
* software. 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)setenv.c 5.4 (Berkeley) 6/1/90";
#endif /* LIBC_SCCS and not lint */
#include <stdio.h>
#include <sys/types.h>
extern char *malloc();
#ifdef BSD4_2
#define memcpy(a,b,c) bcopy(b,a,c)
#endif
/*
* 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 char *name, *value;
int rewrite;
{
extern char **environ;
static int alloced; /* if allocated space before */
register char *C;
int l_value, offset;
char *_findenv();
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 = (char **)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 = 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".
*/
void
unsetenv(name)
char *name;
{
extern char **environ;
register char **P;
int offset;
char *_findenv();
while (_findenv(name, &offset)) /* if set multiple times */
for (P = &environ[offset];; ++P)
if (!(*P = *(P + 1)))
break;
}
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