1 /* Copyright (C) 1992, 1995, 1996, 1997, 2002 Free Software Foundation, Inc. 2 This file based on setenv.c in the GNU C Library. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Library General Public License as 6 published by the Free Software Foundation; either version 2 of the 7 License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Library General Public License for more details. 13 14 You should have received a copy of the GNU Library General Public 15 License along with the GNU C Library; see the file COPYING.LIB. If not, 16 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, 17 Boston, MA 02111-1307, USA. */ 18 19 20 /* 21 22 @deftypefn Supplemental int setenv (const char *@var{name}, const char *@var{value}, int @var{overwrite}) 23 @deftypefnx Supplemental void unsetenv (const char *@var{name}) 24 25 @code{setenv} adds @var{name} to the environment with value 26 @var{value}. If the name was already present in the environment, 27 the new value will be stored only if @var{overwrite} is nonzero. 28 The companion @code{unsetenv} function removes @var{name} from the 29 environment. This implementation is not safe for multithreaded code. 30 31 @end deftypefn 32 33 */ 34 35 #if HAVE_CONFIG_H 36 # include <config.h> 37 #endif 38 39 #define setenv libiberty_setenv 40 #define unsetenv libiberty_unsetenv 41 42 #include "ansidecl.h" 43 #include <sys/types.h> /* For `size_t' */ 44 #include <stdio.h> /* For `NULL' */ 45 46 #include <errno.h> 47 #if !defined(errno) && !defined(HAVE_ERRNO_DECL) 48 extern int errno; 49 #endif 50 #define __set_errno(ev) ((errno) = (ev)) 51 52 #if HAVE_STDLIB_H 53 # include <stdlib.h> 54 #endif 55 #if HAVE_STRING_H 56 # include <string.h> 57 #endif 58 #if HAVE_UNISTD_H 59 # include <unistd.h> 60 #endif 61 62 #define __environ environ 63 #ifndef HAVE_ENVIRON_DECL 64 extern char **environ; 65 #endif 66 67 #undef setenv 68 #undef unsetenv 69 70 /* LOCK and UNLOCK are defined as no-ops. This makes the libiberty 71 * implementation MT-Unsafe. */ 72 #define LOCK 73 #define UNLOCK 74 75 /* Below this point, it's verbatim code from the glibc-2.0 implementation */ 76 77 /* If this variable is not a null pointer we allocated the current 78 environment. */ 79 static char **last_environ; 80 81 82 int 83 setenv (name, value, replace) 84 const char *name; 85 const char *value; 86 int replace; 87 { 88 register char **ep = 0; 89 register size_t size; 90 const size_t namelen = strlen (name); 91 const size_t vallen = strlen (value) + 1; 92 93 LOCK; 94 95 size = 0; 96 if (__environ != NULL) 97 { 98 for (ep = __environ; *ep != NULL; ++ep) 99 if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=') 100 break; 101 else 102 ++size; 103 } 104 105 if (__environ == NULL || *ep == NULL) 106 { 107 char **new_environ; 108 if (__environ == last_environ && __environ != NULL) 109 /* We allocated this space; we can extend it. */ 110 new_environ = (char **) realloc (last_environ, 111 (size + 2) * sizeof (char *)); 112 else 113 new_environ = (char **) malloc ((size + 2) * sizeof (char *)); 114 115 if (new_environ == NULL) 116 { 117 UNLOCK; 118 return -1; 119 } 120 121 new_environ[size] = malloc (namelen + 1 + vallen); 122 if (new_environ[size] == NULL) 123 { 124 free ((char *) new_environ); 125 __set_errno (ENOMEM); 126 UNLOCK; 127 return -1; 128 } 129 130 if (__environ != last_environ) 131 memcpy ((char *) new_environ, (char *) __environ, 132 size * sizeof (char *)); 133 134 memcpy (new_environ[size], name, namelen); 135 new_environ[size][namelen] = '='; 136 memcpy (&new_environ[size][namelen + 1], value, vallen); 137 138 new_environ[size + 1] = NULL; 139 140 last_environ = __environ = new_environ; 141 } 142 else if (replace) 143 { 144 size_t len = strlen (*ep); 145 if (len + 1 < namelen + 1 + vallen) 146 { 147 /* The existing string is too short; malloc a new one. */ 148 char *new = malloc (namelen + 1 + vallen); 149 if (new == NULL) 150 { 151 UNLOCK; 152 return -1; 153 } 154 *ep = new; 155 } 156 memcpy (*ep, name, namelen); 157 (*ep)[namelen] = '='; 158 memcpy (&(*ep)[namelen + 1], value, vallen); 159 } 160 161 UNLOCK; 162 163 return 0; 164 } 165 166 void 167 unsetenv (name) 168 const char *name; 169 { 170 const size_t len = strlen (name); 171 char **ep; 172 173 LOCK; 174 175 for (ep = __environ; *ep; ++ep) 176 if (!strncmp (*ep, name, len) && (*ep)[len] == '=') 177 { 178 /* Found it. Remove this pointer by moving later ones back. */ 179 char **dp = ep; 180 do 181 dp[0] = dp[1]; 182 while (*dp++); 183 /* Continue the loop in case NAME appears again. */ 184 } 185 186 UNLOCK; 187 } 188