1 /* $NetBSD: setenv.c,v 1.10 1997/07/21 14:09:04 jtc Exp $ */ 2 3 /* 4 * Copyright (c) 1987 Regents of the University of California. 5 * 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 = "from: @(#)setenv.c 5.6 (Berkeley) 6/4/91"; 40 #else 41 __RCSID("$NetBSD: setenv.c,v 1.10 1997/07/21 14:09:04 jtc 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 50 #ifdef __weak_alias 51 __weak_alias(setenv,_setenv); 52 __weak_alias(unsetenv,_unsetenv); 53 #endif 54 55 /* 56 * setenv -- 57 * Set the value of the environmental variable "name" to be 58 * "value". If rewrite is set, replace any current value. 59 */ 60 int 61 setenv(name, value, rewrite) 62 register const char *name; 63 register const char *value; 64 int rewrite; 65 { 66 extern char **environ; 67 static int alloced; /* if allocated space before */ 68 register char *C; 69 int l_value, offset; 70 71 if (*value == '=') /* no `=' in value */ 72 ++value; 73 l_value = strlen(value); 74 if ((C = __findenv(name, &offset))) { /* find if already exists */ 75 if (!rewrite) 76 return (0); 77 if (strlen(C) >= l_value) { /* old larger; copy over */ 78 while ((*C++ = *value++) != '\0'); 79 return (0); 80 } 81 } else { /* create new slot */ 82 register int cnt; 83 register char **P; 84 85 for (P = environ, cnt = 0; *P; ++P, ++cnt); 86 if (alloced) { /* just increase size */ 87 environ = (char **)realloc((char *)environ, 88 (size_t)(sizeof(char *) * (cnt + 2))); 89 if (!environ) 90 return (-1); 91 } 92 else { /* get new space */ 93 alloced = 1; /* copy old entries into it */ 94 P = (char **)malloc((size_t)(sizeof(char *) * 95 (cnt + 2))); 96 if (!P) 97 return (-1); 98 bcopy(environ, P, cnt * sizeof(char *)); 99 environ = P; 100 } 101 environ[cnt + 1] = NULL; 102 offset = cnt; 103 } 104 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */ 105 if (!(environ[offset] = /* name + `=' + value */ 106 malloc((size_t)((int)(C - name) + l_value + 2)))) 107 return (-1); 108 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C) 109 ; 110 for (*C++ = '='; (*C++ = *value++) != '\0'; ) 111 ; 112 return (0); 113 } 114 115 /* 116 * unsetenv(name) -- 117 * Delete environmental variable "name". 118 */ 119 void 120 unsetenv(name) 121 const char *name; 122 { 123 extern char **environ; 124 register char **P; 125 int offset; 126 127 while (__findenv(name, &offset)) /* if set multiple times */ 128 for (P = &environ[offset];; ++P) 129 if (!(*P = *(P + 1))) 130 break; 131 } 132