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 * 4. 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 sccsid[] = "@(#)getenv.c 8.1 (Berkeley) 6/4/93"; 32 #endif /* LIBC_SCCS and not lint */ 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <stdlib.h> 37 #include <stddef.h> 38 #include <string.h> 39 40 inline char *__findenv(const char *, int *); 41 42 /* 43 * __findenv -- 44 * Returns pointer to value associated with name, if any, else NULL. 45 * Sets offset to be the offset of the name/value combination in the 46 * environmental array, for use by setenv(3) and unsetenv(3). 47 * Explicitly removes '=' in argument name. 48 * 49 * This routine *should* be a static; don't use it. 50 */ 51 inline char * 52 __findenv(name, offset) 53 const char *name; 54 int *offset; 55 { 56 extern char **environ; 57 int len, i; 58 const char *np; 59 char **p, *cp; 60 61 if (name == NULL || environ == NULL) 62 return (NULL); 63 for (np = name; *np && *np != '='; ++np) 64 continue; 65 len = np - name; 66 for (p = environ; (cp = *p) != NULL; ++p) { 67 for (np = name, i = len; i && *cp; i--) 68 if (*cp++ != *np++) 69 break; 70 if (i == 0 && *cp++ == '=') { 71 *offset = p - environ; 72 return (cp); 73 } 74 } 75 return (NULL); 76 } 77 78 /* 79 * getenv -- 80 * Returns ptr to value associated with name, if any, else NULL. 81 */ 82 char * 83 getenv(name) 84 const char *name; 85 { 86 int offset; 87 88 return (__findenv(name, &offset)); 89 } 90