1 /* $NetBSD: setenv.c,v 1.15 1998/11/15 17:13:51 christos 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: setenv.c,v 1.15 1998/11/15 17:13:51 christos Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <stdlib.h> 47 #include <string.h> 48 #include "local.h" 49 #include "reentrant.h" 50 51 #ifdef __weak_alias 52 __weak_alias(setenv,_setenv); 53 __weak_alias(unsetenv,_unsetenv); 54 #endif 55 56 #ifdef _REENT 57 extern rwlock_t __environ_lock; 58 #endif 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 extern char **environ; 72 static int alloced; /* if allocated space before */ 73 char *c; 74 const char *cc; 75 int l_value, offset; 76 77 if (*value == '=') /* no `=' in value */ 78 ++value; 79 l_value = strlen(value); 80 rwlock_wrlock(&__environ_lock); 81 /* find if already exists */ 82 if ((c = __findenv(name, &offset)) != NULL) { 83 if (!rewrite) { 84 rwlock_unlock(&__environ_lock); 85 return (0); 86 } 87 if (strlen(c) >= l_value) { /* old larger; copy over */ 88 while ((*c++ = *value++) != '\0'); 89 rwlock_unlock(&__environ_lock); 90 return (0); 91 } 92 } else { /* create new slot */ 93 int cnt; 94 char **p; 95 96 for (p = environ, cnt = 0; *p; ++p, ++cnt); 97 if (alloced) { /* just increase size */ 98 environ = realloc(environ, 99 (size_t)(sizeof(char *) * (cnt + 2))); 100 if (!environ) { 101 rwlock_unlock(&__environ_lock); 102 return (-1); 103 } 104 } 105 else { /* get new space */ 106 alloced = 1; /* copy old entries into it */ 107 p = malloc((size_t)(sizeof(char *) * (cnt + 2))); 108 if (!p) { 109 rwlock_unlock(&__environ_lock); 110 return (-1); 111 } 112 memcpy(p, environ, cnt * sizeof(char *)); 113 environ = p; 114 } 115 environ[cnt + 1] = NULL; 116 offset = cnt; 117 } 118 for (cc = name; *cc && *cc != '='; ++cc)/* no `=' in name */ 119 continue; 120 if (!(environ[offset] = /* name + `=' + value */ 121 malloc((size_t)((int)(cc - name) + l_value + 2)))) { 122 rwlock_unlock(&__environ_lock); 123 return (-1); 124 } 125 for (c = environ[offset]; (*c = *name++) && *c != '='; ++c); 126 for (*c++ = '='; (*c++ = *value++) != '\0'; ); 127 rwlock_unlock(&__environ_lock); 128 return (0); 129 } 130 131 /* 132 * unsetenv(name) -- 133 * Delete environmental variable "name". 134 */ 135 void 136 unsetenv(name) 137 const char *name; 138 { 139 extern char **environ; 140 char **p; 141 int offset; 142 143 rwlock_wrlock(&__environ_lock); 144 while (__findenv(name, &offset)) /* if set multiple times */ 145 for (p = &environ[offset];; ++p) 146 if (!(*p = *(p + 1))) 147 break; 148 rwlock_unlock(&__environ_lock); 149 } 150