1 /* $NetBSD: getenv.c,v 1.6 1995/12/28 08:52:18 thorpej 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 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char *sccsid = "from: @(#)getenv.c 5.8 (Berkeley) 2/23/91"; 39 #else 40 static char *rcsid = "$NetBSD: getenv.c,v 1.6 1995/12/28 08:52:18 thorpej Exp $"; 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <stdlib.h> 45 #include <string.h> 46 47 /* 48 * getenv -- 49 * Returns ptr to value associated with name, if any, else NULL. 50 */ 51 char * 52 getenv(name) 53 const char *name; 54 { 55 int offset; 56 char *__findenv(); 57 58 return(__findenv(name, &offset)); 59 } 60 61 /* 62 * __findenv -- 63 * Returns pointer to value associated with name, if any, else NULL. 64 * Sets offset to be the offset of the name/value combination in the 65 * environmental array, for use by setenv(3) and unsetenv(3). 66 * Explicitly removes '=' in argument name. 67 * 68 * This routine *should* be a static; don't use it. 69 */ 70 char * 71 __findenv(name, offset) 72 register char *name; 73 int *offset; 74 { 75 extern char **environ; 76 register int len; 77 register char **P, *C; 78 79 for (C = name, len = 0; *C && *C != '='; ++C, ++len); 80 for (P = environ; *P; ++P) 81 if (!strncmp(*P, name, len)) 82 if (*(C = *P + len) == '=') { 83 *offset = P - environ; 84 return(++C); 85 } 86 return(NULL); 87 } 88