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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if defined(LIBC_SCCS) && !defined(lint) 31 static char *rcsid = "$OpenBSD: setenv.c,v 1.6 2003/06/02 20:18:38 millert Exp $"; 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include <stdlib.h> 35 #include <string.h> 36 37 char *__findenv(const char *name, int *offset); 38 39 /* 40 * setenv -- 41 * Set the value of the environmental variable "name" to be 42 * "value". If rewrite is set, replace any current value. 43 */ 44 int 45 setenv(name, value, rewrite) 46 register const char *name; 47 register const char *value; 48 int rewrite; 49 { 50 extern char **environ; 51 static int alloced; /* if allocated space before */ 52 register char *C; 53 int l_value, offset; 54 55 if (*value == '=') /* no `=' in value */ 56 ++value; 57 l_value = strlen(value); 58 if ((C = __findenv(name, &offset))) { /* find if already exists */ 59 if (!rewrite) 60 return (0); 61 if (strlen(C) >= l_value) { /* old larger; copy over */ 62 while ((*C++ = *value++)) 63 ; 64 return (0); 65 } 66 } else { /* create new slot */ 67 register int cnt; 68 register char **P; 69 70 for (P = environ, cnt = 0; *P; ++P, ++cnt); 71 if (alloced) { /* just increase size */ 72 P = (char **)realloc((void *)environ, 73 (size_t)(sizeof(char *) * (cnt + 2))); 74 if (!P) 75 return (-1); 76 environ = P; 77 } 78 else { /* get new space */ 79 alloced = 1; /* copy old entries into it */ 80 P = (char **)malloc((size_t)(sizeof(char *) * 81 (cnt + 2))); 82 if (!P) 83 return (-1); 84 bcopy(environ, P, cnt * sizeof(char *)); 85 environ = P; 86 } 87 environ[cnt + 1] = NULL; 88 offset = cnt; 89 } 90 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */ 91 if (!(environ[offset] = /* name + `=' + value */ 92 malloc((size_t)((int)(C - name) + l_value + 2)))) 93 return (-1); 94 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C) 95 ; 96 for (*C++ = '='; (*C++ = *value++); ) 97 ; 98 return (0); 99 } 100 101 /* 102 * unsetenv(name) -- 103 * Delete environmental variable "name". 104 */ 105 void 106 unsetenv(name) 107 const char *name; 108 { 109 extern char **environ; 110 register char **P; 111 int offset; 112 char *__findenv(); 113 114 while (__findenv(name, &offset)) /* if set multiple times */ 115 for (P = &environ[offset];; ++P) 116 if (!(*P = *(P + 1))) 117 break; 118 } 119