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 #include "includes.h" 35 #ifndef HAVE_SETENV 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 static char *rcsid = "$OpenBSD: setenv.c,v 1.4 2001/07/09 06:57:45 deraadt Exp $"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <stdlib.h> 42 #include <string.h> 43 44 /* 45 * __findenv -- 46 * Returns pointer to value associated with name, if any, else NULL. 47 * Sets offset to be the offset of the name/value combination in the 48 * environmental array, for use by setenv(3) and unsetenv(3). 49 * Explicitly removes '=' in argument name. 50 * 51 * This routine *should* be a static; don't use it. 52 */ 53 char * 54 __findenv(name, offset) 55 register const char *name; 56 int *offset; 57 { 58 extern char **environ; 59 register int len, i; 60 register const char *np; 61 register char **p, *cp; 62 63 if (name == NULL || environ == NULL) 64 return (NULL); 65 for (np = name; *np && *np != '='; ++np) 66 ; 67 len = np - name; 68 for (p = environ; (cp = *p) != NULL; ++p) { 69 for (np = name, i = len; i && *cp; i--) 70 if (*cp++ != *np++) 71 break; 72 if (i == 0 && *cp++ == '=') { 73 *offset = p - environ; 74 return (cp); 75 } 76 } 77 return (NULL); 78 } 79 80 /* 81 * setenv -- 82 * Set the value of the environmental variable "name" to be 83 * "value". If rewrite is set, replace any current value. 84 */ 85 int 86 setenv(name, value, rewrite) 87 register const char *name; 88 register const char *value; 89 int rewrite; 90 { 91 extern char **environ; 92 static int alloced; /* if allocated space before */ 93 register char *C; 94 int l_value, offset; 95 char *__findenv(); 96 97 if (*value == '=') /* no `=' in value */ 98 ++value; 99 l_value = strlen(value); 100 if ((C = __findenv(name, &offset))) { /* find if already exists */ 101 if (!rewrite) 102 return (0); 103 if (strlen(C) >= l_value) { /* old larger; copy over */ 104 while ((*C++ = *value++)) 105 ; 106 return (0); 107 } 108 } else { /* create new slot */ 109 register int cnt; 110 register char **P; 111 112 for (P = environ, cnt = 0; *P; ++P, ++cnt); 113 if (alloced) { /* just increase size */ 114 P = (char **)realloc((void *)environ, 115 (size_t)(sizeof(char *) * (cnt + 2))); 116 if (!P) 117 return (-1); 118 environ = P; 119 } 120 else { /* get new space */ 121 alloced = 1; /* copy old entries into it */ 122 P = (char **)malloc((size_t)(sizeof(char *) * 123 (cnt + 2))); 124 if (!P) 125 return (-1); 126 memmove(P, environ, cnt * sizeof(char *)); 127 environ = P; 128 } 129 environ[cnt + 1] = NULL; 130 offset = cnt; 131 } 132 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */ 133 if (!(environ[offset] = /* name + `=' + value */ 134 malloc((size_t)((int)(C - name) + l_value + 2)))) 135 return (-1); 136 /* LINTED */ 137 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C) 138 ; 139 for (*C++ = '='; (*C++ = *value++); ) 140 ; 141 return (0); 142 } 143 144 /* 145 * unsetenv(name) -- 146 * Delete environmental variable "name". 147 */ 148 void 149 unsetenv(name) 150 const char *name; 151 { 152 extern char **environ; 153 register char **P; 154 int offset; 155 char *__findenv(); 156 157 while (__findenv(name, &offset)) /* if set multiple times */ 158 for (P = &environ[offset];; ++P) 159 /* LINTED */ 160 if (!(*P = *(P + 1))) 161 break; 162 } 163 164 #endif /* HAVE_SETENV */ 165 166 #pragma ident "%Z%%M% %I% %E% SMI" 167