1 /* $NetBSD: getenv.c,v 1.8 1997/07/13 20:16:41 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1987 Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char *sccsid = "from: @(#)getenv.c 5.8 (Berkeley) 2/23/91"; 40 #else 41 __RCSID("$NetBSD: getenv.c,v 1.8 1997/07/13 20:16:41 christos Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <stdlib.h> 46 #include <string.h> 47 #include "local.h" 48 49 /* 50 * getenv -- 51 * Returns ptr to value associated with name, if any, else NULL. 52 */ 53 char * 54 getenv(name) 55 const char *name; 56 { 57 int offset; 58 59 return(__findenv(name, &offset)); 60 } 61 62 /* 63 * __findenv -- 64 * Returns pointer to value associated with name, if any, else NULL. 65 * Sets offset to be the offset of the name/value combination in the 66 * environmental array, for use by setenv(3) and unsetenv(3). 67 * Explicitly removes '=' in argument name. 68 * 69 * This routine *should* be a static; don't use it. 70 */ 71 char * 72 __findenv(name, offset) 73 register const char *name; 74 int *offset; 75 { 76 extern char **environ; 77 register int len; 78 register char **P, *C; 79 register const char *tmp; 80 81 for (tmp = name, len = 0; *tmp && *tmp != '='; ++tmp, ++len); 82 for (P = environ; *P; ++P) 83 if (!strncmp(*P, name, len)) 84 if (*(C = *P + len) == '=') { 85 *offset = P - environ; 86 return(++C); 87 } 88 return(NULL); 89 } 90