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 * @(#)getenv.c 8.1 (Berkeley) 6/4/93 34 * $DragonFly: src/lib/libc/stdlib/getenv.c,v 1.5 2005/04/28 13:51:55 joerg Exp $ 35 */ 36 37 #include <stdlib.h> 38 #include <stddef.h> 39 #include <string.h> 40 41 char *__findenv(const char *, size_t *); 42 43 extern char **environ; 44 45 /* 46 * __findenv -- 47 * Returns pointer to value associated with name, if any, else NULL. 48 * Sets offset to be the offset of the name/value combination in the 49 * environmental array, for use by setenv(3) and unsetenv(3). 50 * Explicitly removes '=' in argument name. 51 * 52 * This routine *should* be a static; don't use it. 53 */ 54 char * 55 __findenv(const char *name, size_t *offset) 56 { 57 size_t len, i; 58 const char *np; 59 char **p, *cp; 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; (cp = *p) != NULL; ++p) { 67 for (np = name, i = len; i && *cp; i--) 68 if (*cp++ != *np++) 69 break; 70 if (i == 0 && *cp++ == '=') { 71 *offset = p - environ; 72 return (cp); 73 } 74 } 75 return (NULL); 76 } 77 78 /* 79 * getenv -- 80 * Returns ptr to value associated with name, if any, else NULL. 81 */ 82 char * 83 getenv(const char *name) 84 { 85 size_t offset; 86 87 return (__findenv(name, &offset)); 88 } 89