1 /* $NetBSD: setenv.c,v 1.23 2003/08/07 16:43:44 agc Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: setenv.c,v 1.23 2003/08/07 16:43:44 agc Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 43 #include <assert.h> 44 #include <errno.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include "local.h" 48 #include "reentrant.h" 49 50 #ifdef __weak_alias 51 __weak_alias(setenv,_setenv) 52 #endif 53 54 #ifdef _REENTRANT 55 extern rwlock_t __environ_lock; 56 #endif 57 58 extern char **environ; 59 60 /* 61 * setenv -- 62 * Set the value of the environmental variable "name" to be 63 * "value". If rewrite is set, replace any current value. 64 */ 65 int 66 setenv(name, value, rewrite) 67 const char *name; 68 const char *value; 69 int rewrite; 70 { 71 static int alloced; /* if allocated space before */ 72 char *c; 73 const char *cc; 74 size_t l_value; 75 int offset; 76 77 _DIAGASSERT(name != NULL); 78 _DIAGASSERT(value != NULL); 79 80 if (*value == '=') /* no `=' in value */ 81 ++value; 82 l_value = strlen(value); 83 rwlock_wrlock(&__environ_lock); 84 /* find if already exists */ 85 if ((c = __findenv(name, &offset)) != NULL) { 86 if (!rewrite) { 87 rwlock_unlock(&__environ_lock); 88 return (0); 89 } 90 if (strlen(c) >= l_value) { /* old larger; copy over */ 91 while ((*c++ = *value++) != '\0'); 92 rwlock_unlock(&__environ_lock); 93 return (0); 94 } 95 } else { /* create new slot */ 96 int cnt; 97 char **p; 98 99 for (p = environ, cnt = 0; *p; ++p, ++cnt); 100 if (alloced) { /* just increase size */ 101 environ = realloc(environ, 102 (size_t)(sizeof(char *) * (cnt + 2))); 103 if (!environ) { 104 rwlock_unlock(&__environ_lock); 105 return (-1); 106 } 107 } 108 else { /* get new space */ 109 alloced = 1; /* copy old entries into it */ 110 p = malloc((size_t)(sizeof(char *) * (cnt + 2))); 111 if (!p) { 112 rwlock_unlock(&__environ_lock); 113 return (-1); 114 } 115 memcpy(p, environ, cnt * sizeof(char *)); 116 environ = p; 117 } 118 environ[cnt + 1] = NULL; 119 offset = cnt; 120 } 121 for (cc = name; *cc && *cc != '='; ++cc)/* no `=' in name */ 122 continue; 123 if (!(environ[offset] = /* name + `=' + value */ 124 malloc((size_t)((int)(cc - name) + l_value + 2)))) { 125 rwlock_unlock(&__environ_lock); 126 return (-1); 127 } 128 for (c = environ[offset]; (*c = *name++) && *c != '='; ++c); 129 for (*c++ = '='; (*c++ = *value++) != '\0'; ); 130 rwlock_unlock(&__environ_lock); 131 return (0); 132 } 133