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 1.5 2002/12/10 22:44:13 mickey Exp $"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <stdlib.h> 42 #include <string.h> 43 44 char *__findenv(const char *name, int *offset); 45 46 /* 47 * __findenv -- 48 * Returns pointer to value associated with name, if any, else NULL. 49 * Sets offset to be the offset of the name/value combination in the 50 * environmental array, for use by setenv(3) and unsetenv(3). 51 * Explicitly removes '=' in argument name. 52 * 53 * This routine *should* be a static; don't use it. 54 */ 55 char * 56 __findenv(name, offset) 57 register const char *name; 58 int *offset; 59 { 60 extern char **environ; 61 register int len, i; 62 register const char *np; 63 register char **p, *cp; 64 65 if (name == NULL || environ == NULL) 66 return (NULL); 67 for (np = name; *np && *np != '='; ++np) 68 ; 69 len = np - name; 70 for (p = environ; (cp = *p) != NULL; ++p) { 71 for (np = name, i = len; i && *cp; i--) 72 if (*cp++ != *np++) 73 break; 74 if (i == 0 && *cp++ == '=') { 75 *offset = p - environ; 76 return (cp); 77 } 78 } 79 return (NULL); 80 } 81 82 /* 83 * setenv -- 84 * Set the value of the environmental variable "name" to be 85 * "value". If rewrite is set, replace any current value. 86 */ 87 int 88 setenv(name, value, rewrite) 89 register const char *name; 90 register const char *value; 91 int rewrite; 92 { 93 extern char **environ; 94 static int alloced; /* if allocated space before */ 95 register char *C; 96 int l_value, offset; 97 98 if (*value == '=') /* no `=' in value */ 99 ++value; 100 l_value = strlen(value); 101 if ((C = __findenv(name, &offset))) { /* find if already exists */ 102 if (!rewrite) 103 return (0); 104 if (strlen(C) >= l_value) { /* old larger; copy over */ 105 while ((*C++ = *value++)) 106 ; 107 return (0); 108 } 109 } else { /* create new slot */ 110 register int cnt; 111 register char **P; 112 113 for (P = environ, cnt = 0; *P; ++P, ++cnt); 114 if (alloced) { /* just increase size */ 115 P = (char **)realloc((void *)environ, 116 (size_t)(sizeof(char *) * (cnt + 2))); 117 if (!P) 118 return (-1); 119 environ = P; 120 } 121 else { /* get new space */ 122 alloced = 1; /* copy old entries into it */ 123 P = (char **)malloc((size_t)(sizeof(char *) * 124 (cnt + 2))); 125 if (!P) 126 return (-1); 127 memmove(P, environ, cnt * sizeof(char *)); 128 environ = P; 129 } 130 environ[cnt + 1] = NULL; 131 offset = cnt; 132 } 133 for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */ 134 if (!(environ[offset] = /* name + `=' + value */ 135 malloc((size_t)((int)(C - name) + l_value + 2)))) 136 return (-1); 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 if (!(*P = *(P + 1))) 160 break; 161 } 162 163 #endif /* HAVE_SETENV */ 164