1 /* Copyright (C) 1992, 1995, 1996, 1997, 2002, 2011 Free Software Foundation, 2 Inc. 3 This file based on setenv.c in the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Library General Public License as 7 published by the Free Software Foundation; either version 2 of the 8 License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Library General Public License for more details. 14 15 You should have received a copy of the GNU Library General Public 16 License along with the GNU C Library; see the file COPYING.LIB. If not, 17 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, 18 Boston, MA 02110-1301, USA. */ 19 20 21 /* 22 23 @deftypefn Supplemental int setenv (const char *@var{name}, @ 24 const char *@var{value}, int @var{overwrite}) 25 @deftypefnx Supplemental void unsetenv (const char *@var{name}) 26 27 @code{setenv} adds @var{name} to the environment with value 28 @var{value}. If the name was already present in the environment, 29 the new value will be stored only if @var{overwrite} is nonzero. 30 The companion @code{unsetenv} function removes @var{name} from the 31 environment. This implementation is not safe for multithreaded code. 32 33 @end deftypefn 34 35 */ 36 37 #if HAVE_CONFIG_H 38 # include <config.h> 39 #endif 40 41 #define setenv libiberty_setenv 42 #define unsetenv libiberty_unsetenv 43 44 #include "ansidecl.h" 45 #include <sys/types.h> /* For `size_t' */ 46 #include <stdio.h> /* For `NULL' */ 47 48 #include <errno.h> 49 #if !defined(errno) && !defined(HAVE_ERRNO_DECL) 50 extern int errno; 51 #endif 52 #define __set_errno(ev) ((errno) = (ev)) 53 54 #if HAVE_STDLIB_H 55 # include <stdlib.h> 56 #endif 57 #if HAVE_STRING_H 58 # include <string.h> 59 #endif 60 #if HAVE_UNISTD_H 61 # include <unistd.h> 62 #endif 63 64 #define __environ environ 65 #ifndef HAVE_ENVIRON_DECL 66 extern char **environ; 67 #endif 68 69 #undef setenv 70 #undef unsetenv 71 72 /* LOCK and UNLOCK are defined as no-ops. This makes the libiberty 73 * implementation MT-Unsafe. */ 74 #define LOCK 75 #define UNLOCK 76 77 /* Below this point, it's verbatim code from the glibc-2.0 implementation */ 78 79 /* If this variable is not a null pointer we allocated the current 80 environment. */ 81 static char **last_environ; 82 83 84 int 85 setenv (const char *name, const char *value, int replace) 86 { 87 register char **ep = 0; 88 register size_t size; 89 const size_t namelen = strlen (name); 90 const size_t vallen = strlen (value) + 1; 91 92 LOCK; 93 94 size = 0; 95 if (__environ != NULL) 96 { 97 for (ep = __environ; *ep != NULL; ++ep) 98 if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=') 99 break; 100 else 101 ++size; 102 } 103 104 if (__environ == NULL || *ep == NULL) 105 { 106 char **new_environ; 107 if (__environ == last_environ && __environ != NULL) 108 /* We allocated this space; we can extend it. */ 109 new_environ = (char **) realloc (last_environ, 110 (size + 2) * sizeof (char *)); 111 else 112 new_environ = (char **) malloc ((size + 2) * sizeof (char *)); 113 114 if (new_environ == NULL) 115 { 116 UNLOCK; 117 return -1; 118 } 119 120 new_environ[size] = (char *) malloc (namelen + 1 + vallen); 121 if (new_environ[size] == NULL) 122 { 123 free ((char *) new_environ); 124 __set_errno (ENOMEM); 125 UNLOCK; 126 return -1; 127 } 128 129 if (__environ != last_environ) 130 memcpy ((char *) new_environ, (char *) __environ, 131 size * sizeof (char *)); 132 133 memcpy (new_environ[size], name, namelen); 134 new_environ[size][namelen] = '='; 135 memcpy (&new_environ[size][namelen + 1], value, vallen); 136 137 new_environ[size + 1] = NULL; 138 139 last_environ = __environ = new_environ; 140 } 141 else if (replace) 142 { 143 size_t len = strlen (*ep); 144 if (len + 1 < namelen + 1 + vallen) 145 { 146 /* The existing string is too short; malloc a new one. */ 147 char *new_string = (char *) malloc (namelen + 1 + vallen); 148 if (new_string == NULL) 149 { 150 UNLOCK; 151 return -1; 152 } 153 *ep = new_string; 154 } 155 memcpy (*ep, name, namelen); 156 (*ep)[namelen] = '='; 157 memcpy (&(*ep)[namelen + 1], value, vallen); 158 } 159 160 UNLOCK; 161 162 return 0; 163 } 164 165 void 166 unsetenv (const char *name) 167 { 168 const size_t len = strlen (name); 169 char **ep; 170 171 LOCK; 172 173 for (ep = __environ; *ep; ++ep) 174 if (!strncmp (*ep, name, len) && (*ep)[len] == '=') 175 { 176 /* Found it. Remove this pointer by moving later ones back. */ 177 char **dp = ep; 178 do 179 dp[0] = dp[1]; 180 while (*dp++); 181 /* Continue the loop in case NAME appears again. */ 182 } 183 184 UNLOCK; 185 } 186
