1 /* 2 * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska H�gskolan 3 * (Royal Institute of Technology, Stockholm, Sweden). 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 #ifdef HAVE_CONFIG_H 35 #include <config.h> 36 RCSID("$Id: putenv.c,v 1.7 2000/03/26 23:08:24 assar Exp $"); 37 #endif 38 39 #include <stdlib.h> 40 41 extern char **environ; 42 43 /* 44 * putenv -- 45 * String points to a string of the form name=value. 46 * 47 * Makes the value of the environment variable name equal to 48 * value by altering an existing variable or creating a new one. 49 */ 50 51 int 52 putenv(const char *string) 53 { 54 int i; 55 const char *eq = (const char *)strchr(string, '='); 56 int len; 57 58 if (eq == NULL) 59 return 1; 60 len = eq - string; 61 62 if(environ == NULL) { 63 environ = malloc(sizeof(char*)); 64 if(environ == NULL) 65 return 1; 66 environ[0] = NULL; 67 } 68 69 for(i = 0; environ[i] != NULL; i++) 70 if(strncmp(string, environ[i], len) == 0) { 71 environ[i] = string; 72 return 0; 73 } 74 environ = realloc(environ, sizeof(char*) * (i + 2)); 75 if(environ == NULL) 76 return 1; 77 environ[i] = string; 78 environ[i+1] = NULL; 79 return 0; 80 } 81