/* Environment handling for dynamic loader. Copyright (C) 1995-2019 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ #include <string.h> #include <stdlib.h> #include <unistd.h> #include <ldsodefs.h> /* Walk through the environment of the process and return all entries starting with `LD_'. */ char * _dl_next_ld_env_entry (char ***position) { char **current = *position; char *result = NULL; while (*current != NULL) { if (__builtin_expect ((*current)[0] == 'L', 0) && (*current)[1] == 'D' && (*current)[2] == '_') { result = &(*current)[3]; /* Save current position for next visit. */ *position = ++current; break; } ++current; } return result; } /* In ld.so __environ is not exported. */ extern char **__environ attribute_hidden; int unsetenv (const char *name) { char **ep; ep = __environ; while (*ep != NULL) { size_t cnt = 0; while ((*ep)[cnt] == name[cnt] && name[cnt] != '\0') ++cnt; if (name[cnt] == '\0' && (*ep)[cnt] == '=') { /* Found it. Remove this pointer by moving later ones to the front. */ char **dp = ep; do dp[0] = dp[1]; while (*dp++); /* Continue the loop in case NAME appears again. */ } else ++ep; } return 0; }