17c478bd9Sstevel@tonic-gate #if defined(LIBC_SCCS) && !defined(lint)
2*9525b14bSRao Shoaib static const char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93";
3*9525b14bSRao Shoaib static const char rcsid[] = "$Id: setenv.c,v 1.2 2005/04/27 04:56:11 sra Exp $";
47c478bd9Sstevel@tonic-gate #endif /* LIBC_SCCS and not lint */
57c478bd9Sstevel@tonic-gate
67c478bd9Sstevel@tonic-gate /*
77c478bd9Sstevel@tonic-gate * Copyright (c) 1987, 1993
87c478bd9Sstevel@tonic-gate * The Regents of the University of California. All rights reserved.
97c478bd9Sstevel@tonic-gate *
107c478bd9Sstevel@tonic-gate * Redistribution and use in source and binary forms, with or without
117c478bd9Sstevel@tonic-gate * modification, are permitted provided that the following conditions
127c478bd9Sstevel@tonic-gate * are met:
137c478bd9Sstevel@tonic-gate * 1. Redistributions of source code must retain the above copyright
147c478bd9Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer.
157c478bd9Sstevel@tonic-gate * 2. Redistributions in binary form must reproduce the above copyright
167c478bd9Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer in the
177c478bd9Sstevel@tonic-gate * documentation and/or other materials provided with the distribution.
187c478bd9Sstevel@tonic-gate * 3. All advertising materials mentioning features or use of this software
197c478bd9Sstevel@tonic-gate * must display the following acknowledgement:
207c478bd9Sstevel@tonic-gate * This product includes software developed by the University of
217c478bd9Sstevel@tonic-gate * California, Berkeley and its contributors.
227c478bd9Sstevel@tonic-gate * 4. Neither the name of the University nor the names of its contributors
237c478bd9Sstevel@tonic-gate * may be used to endorse or promote products derived from this software
247c478bd9Sstevel@tonic-gate * without specific prior written permission.
257c478bd9Sstevel@tonic-gate *
267c478bd9Sstevel@tonic-gate * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
277c478bd9Sstevel@tonic-gate * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
287c478bd9Sstevel@tonic-gate * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
297c478bd9Sstevel@tonic-gate * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
307c478bd9Sstevel@tonic-gate * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
317c478bd9Sstevel@tonic-gate * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
327c478bd9Sstevel@tonic-gate * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
337c478bd9Sstevel@tonic-gate * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
347c478bd9Sstevel@tonic-gate * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
357c478bd9Sstevel@tonic-gate * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
367c478bd9Sstevel@tonic-gate * SUCH DAMAGE.
377c478bd9Sstevel@tonic-gate */
387c478bd9Sstevel@tonic-gate
397c478bd9Sstevel@tonic-gate #include "port_before.h"
407c478bd9Sstevel@tonic-gate
417c478bd9Sstevel@tonic-gate #include <stddef.h>
427c478bd9Sstevel@tonic-gate #include <stdlib.h>
437c478bd9Sstevel@tonic-gate #include <string.h>
447c478bd9Sstevel@tonic-gate
457c478bd9Sstevel@tonic-gate #include "port_after.h"
467c478bd9Sstevel@tonic-gate
477c478bd9Sstevel@tonic-gate #if !defined(NEED_SETENV)
487c478bd9Sstevel@tonic-gate int __bindcompat_setenv;
497c478bd9Sstevel@tonic-gate #else
507c478bd9Sstevel@tonic-gate
517c478bd9Sstevel@tonic-gate extern char **environ;
527c478bd9Sstevel@tonic-gate
537c478bd9Sstevel@tonic-gate static char *findenv(const char *name, int *offset);
547c478bd9Sstevel@tonic-gate
55*9525b14bSRao Shoaib /*%
567c478bd9Sstevel@tonic-gate * setenv --
577c478bd9Sstevel@tonic-gate * Set the value of the environmental variable "name" to be
587c478bd9Sstevel@tonic-gate * "value". If rewrite is set, replace any current value.
597c478bd9Sstevel@tonic-gate */
setenv(const char * name,const char * value,int rewrite)607c478bd9Sstevel@tonic-gate setenv(const char *name, const char *value, int rewrite) {
617c478bd9Sstevel@tonic-gate extern char **environ;
62*9525b14bSRao Shoaib static int alloced; /*%< if allocated space before */
637c478bd9Sstevel@tonic-gate char *c;
647c478bd9Sstevel@tonic-gate int l_value, offset;
657c478bd9Sstevel@tonic-gate
66*9525b14bSRao Shoaib if (*value == '=') /*%< no `=' in value */
677c478bd9Sstevel@tonic-gate ++value;
687c478bd9Sstevel@tonic-gate l_value = strlen(value);
69*9525b14bSRao Shoaib if ((c = findenv(name, &offset))) { /*%< find if already exists */
707c478bd9Sstevel@tonic-gate if (!rewrite)
717c478bd9Sstevel@tonic-gate return (0);
72*9525b14bSRao Shoaib if (strlen(c) >= l_value) { /*%< old larger; copy over */
737c478bd9Sstevel@tonic-gate while (*c++ = *value++);
747c478bd9Sstevel@tonic-gate return (0);
757c478bd9Sstevel@tonic-gate }
76*9525b14bSRao Shoaib } else { /*%< create new slot */
777c478bd9Sstevel@tonic-gate int cnt;
787c478bd9Sstevel@tonic-gate char **p;
797c478bd9Sstevel@tonic-gate
807c478bd9Sstevel@tonic-gate for (p = environ, cnt = 0; *p; ++p, ++cnt);
81*9525b14bSRao Shoaib if (alloced) { /*%< just increase size */
827c478bd9Sstevel@tonic-gate environ = (char **)realloc((char *)environ,
837c478bd9Sstevel@tonic-gate (size_t)(sizeof(char *) * (cnt + 2)));
847c478bd9Sstevel@tonic-gate if (!environ)
857c478bd9Sstevel@tonic-gate return (-1);
867c478bd9Sstevel@tonic-gate }
87*9525b14bSRao Shoaib else { /*%< get new space */
88*9525b14bSRao Shoaib alloced = 1; /*%< copy old entries into it */
897c478bd9Sstevel@tonic-gate p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
907c478bd9Sstevel@tonic-gate if (!p)
917c478bd9Sstevel@tonic-gate return (-1);
927c478bd9Sstevel@tonic-gate memcpy(p, environ, cnt * sizeof(char *));
937c478bd9Sstevel@tonic-gate environ = p;
947c478bd9Sstevel@tonic-gate }
957c478bd9Sstevel@tonic-gate environ[cnt + 1] = NULL;
967c478bd9Sstevel@tonic-gate offset = cnt;
977c478bd9Sstevel@tonic-gate }
98*9525b14bSRao Shoaib for (c = (char *)name; *c && *c != '='; ++c); /*%< no `=' in name */
99*9525b14bSRao Shoaib if (!(environ[offset] = /*%< name + `=' + value */
1007c478bd9Sstevel@tonic-gate malloc((size_t)((int)(c - name) + l_value + 2))))
1017c478bd9Sstevel@tonic-gate return (-1);
1027c478bd9Sstevel@tonic-gate for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);
1037c478bd9Sstevel@tonic-gate for (*c++ = '='; *c++ = *value++;);
1047c478bd9Sstevel@tonic-gate return (0);
1057c478bd9Sstevel@tonic-gate }
1067c478bd9Sstevel@tonic-gate
107*9525b14bSRao Shoaib /*%
1087c478bd9Sstevel@tonic-gate * unsetenv(name) --
1097c478bd9Sstevel@tonic-gate * Delete environmental variable "name".
1107c478bd9Sstevel@tonic-gate */
1117c478bd9Sstevel@tonic-gate void
unsetenv(const char * name)1127c478bd9Sstevel@tonic-gate unsetenv(const char *name) {
1137c478bd9Sstevel@tonic-gate char **p;
1147c478bd9Sstevel@tonic-gate int offset;
1157c478bd9Sstevel@tonic-gate
116*9525b14bSRao Shoaib while (findenv(name, &offset)) /*%< if set multiple times */
1177c478bd9Sstevel@tonic-gate for (p = &environ[offset];; ++p)
1187c478bd9Sstevel@tonic-gate if (!(*p = *(p + 1)))
1197c478bd9Sstevel@tonic-gate break;
1207c478bd9Sstevel@tonic-gate }
1217c478bd9Sstevel@tonic-gate
122*9525b14bSRao Shoaib /*%
1237c478bd9Sstevel@tonic-gate * findenv --
1247c478bd9Sstevel@tonic-gate * Returns pointer to value associated with name, if any, else NULL.
1257c478bd9Sstevel@tonic-gate * Sets offset to be the offset of the name/value combination in the
1267c478bd9Sstevel@tonic-gate * environmental array, for use by setenv(3) and unsetenv(3).
1277c478bd9Sstevel@tonic-gate * Explicitly removes '=' in argument name.
1287c478bd9Sstevel@tonic-gate *
1297c478bd9Sstevel@tonic-gate * This routine *should* be a static; don't use it.
1307c478bd9Sstevel@tonic-gate */
1317c478bd9Sstevel@tonic-gate static char *
findenv(const char * name,int * offset)1327c478bd9Sstevel@tonic-gate findenv(const char *name, int *offset) {
1337c478bd9Sstevel@tonic-gate const char *np;
1347c478bd9Sstevel@tonic-gate char **p, *c;
1357c478bd9Sstevel@tonic-gate int len;
1367c478bd9Sstevel@tonic-gate
1377c478bd9Sstevel@tonic-gate if (name == NULL || environ == NULL)
1387c478bd9Sstevel@tonic-gate return (NULL);
1397c478bd9Sstevel@tonic-gate for (np = name; *np && *np != '='; ++np)
1407c478bd9Sstevel@tonic-gate continue;
1417c478bd9Sstevel@tonic-gate len = np - name;
1427c478bd9Sstevel@tonic-gate for (p = environ; (c = *p) != NULL; ++p)
1437c478bd9Sstevel@tonic-gate if (strncmp(c, name, len) == 0 && c[len] == '=') {
1447c478bd9Sstevel@tonic-gate *offset = p - environ;
1457c478bd9Sstevel@tonic-gate return (c + len + 1);
1467c478bd9Sstevel@tonic-gate }
1477c478bd9Sstevel@tonic-gate return (NULL);
1487c478bd9Sstevel@tonic-gate }
1497c478bd9Sstevel@tonic-gate #endif
150*9525b14bSRao Shoaib
151*9525b14bSRao Shoaib /*! \file */
152