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 "config.h" 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 static const char sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93"; 38 static const char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93"; 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 static char * 54 __findenv(register char *name, int *offset) 55 { 56 extern char **environ; 57 register int len; 58 register char *np; 59 register char **p, *c; 60 61 if (name == NULL || environ == NULL) 62 return (NULL); 63 for (np = name; *np && *np != '='; ++np) 64 continue; 65 len = np - name; 66 for (p = environ; (c = *p) != NULL; ++p) 67 if (strncmp(c, name, len) == 0 && c[len] == '=') { 68 *offset = p - environ; 69 return (c + len + 1); 70 } 71 return (NULL); 72 } 73 74 #ifndef HAVE_SETENV 75 /* 76 * setenv -- 77 * Set the value of the environmental variable "name" to be 78 * "value". If rewrite is set, replace any current value. 79 * 80 * PUBLIC: #ifndef HAVE_SETENV 81 * PUBLIC: int setenv __P((const char *, const char *, int)); 82 * PUBLIC: #endif 83 */ 84 setenv(name, value, rewrite) 85 register char *name; 86 register char *value; 87 int rewrite; 88 { 89 extern char **environ; 90 static int alloced; /* if allocated space before */ 91 register char *c; 92 int l_value, offset; 93 94 if (*value == '=') /* no `=' in value */ 95 ++value; 96 l_value = strlen(value); 97 if ((c = __findenv(name, &offset))) { /* find if already exists */ 98 if (!rewrite) 99 return (0); 100 if (strlen(c) >= l_value) { /* old larger; copy over */ 101 while (*c++ = *value++); 102 return (0); 103 } 104 } else { /* create new slot */ 105 register int cnt; 106 register char **p; 107 108 for (p = environ, cnt = 0; *p; ++p, ++cnt); 109 if (alloced) { /* just increase size */ 110 environ = (char **)realloc((char *)environ, 111 (size_t)(sizeof(char *) * (cnt + 2))); 112 if (!environ) 113 return (-1); 114 } 115 else { /* get new space */ 116 alloced = 1; /* copy old entries into it */ 117 p = malloc((size_t)(sizeof(char *) * (cnt + 2))); 118 if (!p) 119 return (-1); 120 memmove(p, environ, cnt * sizeof(char *)); 121 environ = p; 122 } 123 environ[cnt + 1] = NULL; 124 offset = cnt; 125 } 126 for (c = (char *)name; *c && *c != '='; ++c); /* no `=' in name */ 127 if (!(environ[offset] = /* name + `=' + value */ 128 malloc((size_t)((int)(c - name) + l_value + 2)))) 129 return (-1); 130 for (c = environ[offset]; (*c = *name++) && *c != '='; ++c); 131 for (*c++ = '='; *c++ = *value++;); 132 return (0); 133 } 134 #endif 135 136 #ifndef HAVE_UNSETENV 137 /* 138 * unsetenv(name) -- 139 * Delete environmental variable "name". 140 * 141 * PUBLIC: #ifndef HAVE_UNSETENV 142 * PUBLIC: void unsetenv __P((const char *)); 143 * PUBLIC: #endif 144 */ 145 void 146 unsetenv(name) 147 char *name; 148 { 149 extern char **environ; 150 register char **p; 151 int offset; 152 153 while (__findenv(name, &offset)) /* if set multiple times */ 154 for (p = &environ[offset];; ++p) 155 if (!(*p = *(p + 1))) 156 break; 157 } 158 #endif 159