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 1.4 1993/10/15 01:26:42 jtc Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <stdlib.h> 40 #include <stddef.h> 41 #include <string.h> 42 43 /* 44 * getenv -- 45 * Returns ptr to value associated with name, if any, else NULL. 46 */ 47 char * 48 getenv(name) 49 const char *name; 50 { 51 int offset; 52 char *__findenv(); 53 54 return(__findenv(name, &offset)); 55 } 56 57 /* 58 * __findenv -- 59 * Returns pointer to value associated with name, if any, else NULL. 60 * Sets offset to be the offset of the name/value combination in the 61 * environmental array, for use by setenv(3) and unsetenv(3). 62 * Explicitly removes '=' in argument name. 63 * 64 * This routine *should* be a static; don't use it. 65 */ 66 char * 67 __findenv(name, offset) 68 register char *name; 69 int *offset; 70 { 71 extern char **environ; 72 register int len; 73 register char **P, *C; 74 75 for (C = name, len = 0; *C && *C != '='; ++C, ++len); 76 for (P = environ; *P; ++P) 77 if (!strncmp(*P, name, len)) 78 if (*(C = *P + len) == '=') { 79 *offset = P - environ; 80 return(++C); 81 } 82 return(NULL); 83 } 84