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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if defined(LIBC_SCCS) && !defined(lint) 31 static char *rcsid = "$OpenBSD: getenv.c,v 1.7 2005/03/30 18:51:49 pat Exp $"; 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include <stdlib.h> 35 #include <string.h> 36 37 char *__findenv(const char *name, int *offset); 38 39 /* 40 * __findenv -- 41 * Returns pointer to value associated with name, if any, else NULL. 42 * Sets offset to be the offset of the name/value combination in the 43 * environmental array, for use by setenv(3) and unsetenv(3). 44 * Explicitly removes '=' in argument name. 45 * 46 * This routine *should* be a static; don't use it. 47 */ 48 char * 49 __findenv(const char *name, int *offset) 50 { 51 extern char **environ; 52 int len, i; 53 const char *np; 54 char **p, *cp; 55 56 if (name == NULL || environ == NULL) 57 return (NULL); 58 for (np = name; *np && *np != '='; ++np) 59 ; 60 len = np - name; 61 for (p = environ; (cp = *p) != NULL; ++p) { 62 for (np = name, i = len; i && *cp; i--) 63 if (*cp++ != *np++) 64 break; 65 if (i == 0 && *cp++ == '=') { 66 *offset = p - environ; 67 return (cp); 68 } 69 } 70 return (NULL); 71 } 72 73 /* 74 * getenv -- 75 * Returns ptr to value associated with name, if any, else NULL. 76 */ 77 char * 78 getenv(const char *name) 79 { 80 int offset; 81 82 return (__findenv(name, &offset)); 83 } 84