1 /* Test of environ variable. 2 Copyright (C) 2008-2021 Free Software Foundation, Inc. 3 4 This program is free software: you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3 of the License, or 7 (at your option) any later version. 8 9 This program 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 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 /* Written by Bruno Haible <bruno@clisp.org>, 2008. */ 18 19 #include <config.h> 20 21 #include <unistd.h> 22 23 #include <string.h> 24 25 int 26 main () /* */ 27 { 28 /* The environment variables that are set even in the weirdest situations 29 are HOME and PATH. 30 POSIX says that HOME is initialized by the system, and that PATH may be 31 unset. But in practice it's more frequent to see HOME unset and PATH 32 set. So we test the presence of PATH. */ 33 char **remaining_variables = environ; 34 char *string; 35 36 for (; (string = *remaining_variables) != NULL; remaining_variables++) 37 { 38 if (strncmp (string, "PATH=", 5) == 0) 39 /* Found the PATH environment variable. */ 40 return 0; 41 } 42 /* Failed to find the PATH environment variable. */ 43 return 1; 44 }