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 1.4 2003/09/06 08:19:16 asmodai Exp $ 35 */ 36 37 #include <stdlib.h> 38 #include <stddef.h> 39 #include <string.h> 40 41 inline char *__findenv (const char *, int *); 42 43 /* 44 * __findenv -- 45 * Returns pointer to value associated with name, if any, else NULL. 46 * Sets offset to be the offset of the name/value combination in the 47 * environmental array, for use by setenv(3) and unsetenv(3). 48 * Explicitly removes '=' in argument name. 49 * 50 * This routine *should* be a static; don't use it. 51 */ 52 inline char * 53 __findenv(name, offset) 54 const char *name; 55 int *offset; 56 { 57 extern char **environ; 58 int len, i; 59 const char *np; 60 char **p, *cp; 61 62 if (name == NULL || environ == NULL) 63 return (NULL); 64 for (np = name; *np && *np != '='; ++np) 65 continue; 66 len = np - name; 67 for (p = environ; (cp = *p) != NULL; ++p) { 68 for (np = name, i = len; i && *cp; i--) 69 if (*cp++ != *np++) 70 break; 71 if (i == 0 && *cp++ == '=') { 72 *offset = p - environ; 73 return (cp); 74 } 75 } 76 return (NULL); 77 } 78 79 /* 80 * getenv -- 81 * Returns ptr to value associated with name, if any, else NULL. 82 */ 83 char * 84 getenv(name) 85 const char *name; 86 { 87 int offset; 88 89 return (__findenv(name, &offset)); 90 } 91