1 /* 2 * Copyright (c) 1987, 1993 3 * The Regents of the University of California. 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 "port_before.h" 35 36 #include <stddef.h> 37 #include <stdlib.h> 38 #include <string.h> 39 40 #include "port_after.h" 41 42 #if !defined(NEED_SETENV) 43 int __bindcompat_setenv; 44 #else 45 46 extern char **environ; 47 48 static char *findenv(const char *name, int *offset); 49 50 /*% 51 * setenv -- 52 * Set the value of the environmental variable "name" to be 53 * "value". If rewrite is set, replace any current value. 54 */ 55 setenv(const char *name, const char *value, int rewrite) { 56 extern char **environ; 57 static int alloced; /*%< if allocated space before */ 58 char *c; 59 int l_value, offset; 60 61 if (*value == '=') /*%< no `=' in value */ 62 ++value; 63 l_value = strlen(value); 64 if ((c = findenv(name, &offset))) { /*%< find if already exists */ 65 if (!rewrite) 66 return (0); 67 if (strlen(c) >= l_value) { /*%< old larger; copy over */ 68 while (*c++ = *value++); 69 return (0); 70 } 71 } else { /*%< create new slot */ 72 int cnt; 73 char **p; 74 75 for (p = environ, cnt = 0; *p; ++p, ++cnt); 76 if (alloced) { /*%< just increase size */ 77 environ = (char **)realloc((char *)environ, 78 (size_t)(sizeof(char *) * (cnt + 2))); 79 if (!environ) 80 return (-1); 81 } 82 else { /*%< get new space */ 83 alloced = 1; /*%< copy old entries into it */ 84 p = malloc((size_t)(sizeof(char *) * (cnt + 2))); 85 if (!p) 86 return (-1); 87 memcpy(p, environ, 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 for (*c++ = '='; *c++ = *value++;); 99 return (0); 100 } 101 102 /*% 103 * unsetenv(name) -- 104 * Delete environmental variable "name". 105 */ 106 void 107 unsetenv(const char *name) { 108 char **p; 109 int offset; 110 111 while (findenv(name, &offset)) /*%< if set multiple times */ 112 for (p = &environ[offset];; ++p) 113 if (!(*p = *(p + 1))) 114 break; 115 } 116 117 /*% 118 * findenv -- 119 * Returns pointer to value associated with name, if any, else NULL. 120 * Sets offset to be the offset of the name/value combination in the 121 * environmental array, for use by setenv(3) and unsetenv(3). 122 * Explicitly removes '=' in argument name. 123 * 124 * This routine *should* be a static; don't use it. 125 */ 126 static char * 127 findenv(const char *name, int *offset) { 128 const char *np; 129 char **p, *c; 130 int len; 131 132 if (name == NULL || environ == NULL) 133 return (NULL); 134 for (np = name; *np && *np != '='; ++np) 135 continue; 136 len = np - name; 137 for (p = environ; (c = *p) != NULL; ++p) 138 if (strncmp(c, name, len) == 0 && c[len] == '=') { 139 *offset = p - environ; 140 return (c + len + 1); 141 } 142 return (NULL); 143 } 144 #endif 145 146 /*! \file */ 147