1 /* $NetBSD: putenv.c,v 1.1.1.1 2016/01/13 18:41:48 christos Exp $ */ 2 3 /* Copyright (C) 1991, 2001 Free Software Foundation, Inc. 4 This file is part of the GNU C Library. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Library General Public License as 8 published by the Free Software Foundation; either version 2 of the 9 License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Library General Public License for more details. 15 16 You should have received a copy of the GNU Library General Public 17 License along with the GNU C Library; see the file COPYING.LIB. If 18 not, write to the Free Software Foundation, Inc., 675 Mass Ave, 19 Cambridge, MA 02139, USA. */ 20 21 /* Hacked slightly by jjc@jclark.com for groff. */ 22 23 #ifdef HAVE_CONFIG_H 24 #include <config.h> 25 #endif 26 27 #include <string.h> 28 29 #ifdef __STDC__ 30 #include <stddef.h> 31 typedef void *PTR; 32 typedef size_t SIZE_T; 33 #else /* not __STDC__ */ 34 typedef char *PTR; 35 typedef int SIZE_T; 36 #endif /* not __STDC__ */ 37 38 #ifdef HAVE_STDLIB_H 39 #include <stdlib.h> 40 #else /* not HAVE_STDLIB_H */ 41 PTR malloc(); 42 #endif /* not HAVE_STDLIB_H */ 43 44 #ifndef NULL 45 #define NULL 0 46 #endif 47 48 extern char **environ; 49 50 /* Put STRING, which is of the form "NAME=VALUE", in the environment. */ 51 52 int putenv(const char *string) 53 { 54 char *name_end = strchr(string, '='); 55 SIZE_T size; 56 char **ep; 57 58 if (name_end == NULL) 59 { 60 /* Remove the variable from the environment. */ 61 size = strlen(string); 62 for (ep = environ; *ep != NULL; ++ep) 63 if (!strncmp(*ep, string, size) && (*ep)[size] == '=') 64 { 65 while (ep[1] != NULL) 66 { 67 ep[0] = ep[1]; 68 ++ep; 69 } 70 *ep = NULL; 71 return 0; 72 } 73 } 74 75 size = 0; 76 for (ep = environ; *ep != NULL; ++ep) 77 if (!strncmp(*ep, string, name_end - string) 78 && (*ep)[name_end - string] == '=') 79 break; 80 else 81 ++size; 82 83 if (*ep == NULL) 84 { 85 static char **last_environ = NULL; 86 char **new_environ = (char **) malloc((size + 2) * sizeof(char *)); 87 if (new_environ == NULL) 88 return -1; 89 (void) memcpy((PTR) new_environ, (PTR) environ, size * sizeof(char *)); 90 new_environ[size] = (char *) string; 91 new_environ[size + 1] = NULL; 92 if (last_environ != NULL) 93 free((PTR) last_environ); 94 last_environ = new_environ; 95 environ = new_environ; 96 } 97 else 98 *ep = (char *) string; 99 100 return 0; 101 } 102