1 /* 2 * Copyright (c) 1987 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char *rcsid = "$OpenBSD: setenv.c,v 1.4 2001/07/09 06:57:45 deraadt Exp $"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <stdlib.h> 39 #include <string.h> 40 41 /* 42 * setenv -- 43 * Set the value of the environmental variable "name" to be 44 * "value". If rewrite is set, replace any current value. 45 */ 46 int 47 setenv(name, value, rewrite) 48 register const char *name; 49 register const char *value; 50 int rewrite; 51 { 52 extern char **environ; 53 static int alloced; /* if allocated space before */ 54 register char *C; 55 int l_value, offset; 56 char *__findenv(); 57 58 if (*value == '=') /* no `=' in value */ 59 ++value; 60 l_value = strlen(value); 61 if ((C = __findenv(name, &offset))) { /* find if already exists */ 62 if (!rewrite) 63 return (0); 64 if (strlen(C) >= l_value) { /* old larger; copy over */ 65 while ((*C++ = *value++)) 66 ; 67 return (0); 68 } 69 } else { /* create new slot */ 70 register int cnt; 71 register char **P; 72 73 for (P = environ, cnt = 0; *P; ++P, ++cnt); 74 if (alloced) { /* just increase size */ 75 P = (char **)realloc((void *)environ, 76 (size_t)(sizeof(char *) * (cnt + 2))); 77 if (!P) 78 return (-1); 79 environ = P; 80 } 81 else { /* get new space */ 82 alloced = 1; /* copy old entries into it */ 83 P = (char **)malloc((size_t)(sizeof(char *) * 84 (cnt + 2))); 85 if (!P) 86 return (-1); 87 bcopy(environ, P, cnt * sizeof(char *)); 88 environ = P; 89 } 90 environ[cnt + 1] = NULL; 91 offset = cnt; 92 } 93 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */ 94 if (!(environ[offset] = /* name + `=' + value */ 95 malloc((size_t)((int)(C - name) + l_value + 2)))) 96 return (-1); 97 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C) 98 ; 99 for (*C++ = '='; (*C++ = *value++); ) 100 ; 101 return (0); 102 } 103 104 /* 105 * unsetenv(name) -- 106 * Delete environmental variable "name". 107 */ 108 void 109 unsetenv(name) 110 const char *name; 111 { 112 extern char **environ; 113 register char **P; 114 int offset; 115 char *__findenv(); 116 117 while (__findenv(name, &offset)) /* if set multiple times */ 118 for (P = &environ[offset];; ++P) 119 if (!(*P = *(P + 1))) 120 break; 121 } 122