1 /* 2 * Copyright (c) 1987 Regents of the University of California. 3 * 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 34 #if defined(LIBC_SCCS) && !defined(lint) 35 /*static char *sccsid = "from: @(#)getenv.c 5.8 (Berkeley) 2/23/91";*/ 36 static char *rcsid = "$Id: getenv.c,v 1.5 1995/02/28 01:46:41 jtc Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <stdlib.h> 40 #include <string.h> 41 42 /* 43 * getenv -- 44 * Returns ptr to value associated with name, if any, else NULL. 45 */ 46 char * 47 getenv(name) 48 const char *name; 49 { 50 int offset; 51 char *__findenv(); 52 53 return(__findenv(name, &offset)); 54 } 55 56 /* 57 * __findenv -- 58 * Returns pointer to value associated with name, if any, else NULL. 59 * Sets offset to be the offset of the name/value combination in the 60 * environmental array, for use by setenv(3) and unsetenv(3). 61 * Explicitly removes '=' in argument name. 62 * 63 * This routine *should* be a static; don't use it. 64 */ 65 char * 66 __findenv(name, offset) 67 register char *name; 68 int *offset; 69 { 70 extern char **environ; 71 register int len; 72 register char **P, *C; 73 74 for (C = name, len = 0; *C && *C != '='; ++C, ++len); 75 for (P = environ; *P; ++P) 76 if (!strncmp(*P, name, len)) 77 if (*(C = *P + len) == '=') { 78 *offset = P - environ; 79 return(++C); 80 } 81 return(NULL); 82 } 83