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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 the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not 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 MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid1[] = "@(#)setenv.c 5.3 (Berkeley) 5/16/90";
static char sccsid2[] = "@(#)getenv.c 5.6 (Berkeley) 5/16/90";
#endif /* LIBC_SCCS and not lint */
#if defined(SOLARIS)
/* for bcopy() and bzero() */
#include "bstring.h"
#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, *malloc();
static int alloced; /* if allocated space before */
register char *C;
int l_value, offset;
static 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,
(sizeof(char *) * (cnt + 2)));
if (!environ)
return(-1);
}
else { /* get new space */
alloced = 1; /* copy old entries into it */
P = (char **)malloc((sizeof(char *) *
(cnt + 2)));
if (!P)
return(-1);
bcopy(environ, P, cnt * sizeof(char *));
environ = P;
}
environ[cnt + 1] = 0;
offset = cnt;
}
for (C = name; *C && *C != '='; ++C); /* no `=' in name */
if (!(environ[offset] = /* name + `=' + value */
malloc(((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;
static char *_findenv();
while (_findenv(name, &offset)) /* if set multiple times */
for (P = &environ[offset];; ++P)
if (!(*P = *(P + 1)))
break;
}
/*
* getenv --
* Returns ptr to value associated with name, if any, else NULL.
*/
char *
getenv(name)
char *name;
{
int offset;
static char *_findenv();
return(_findenv(name, &offset));
}
/*
* _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.
*/
static char *
_findenv(name, offset)
register char *name;
int *offset;
{
extern char **environ;
register int len;
register char **P, *C;
for (C = name, len = 0; *C && *C != '='; ++C, ++len);
for (P = environ; *P; ++P)
if (!strncmp(*P, name, len))
if (*(C = *P + len) == '=') {
*offset = P - environ;
return(++C);
}
return(0);
}
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