/* Copyright (C) 1992, 1995-2002, 2005-2022 Free Software Foundation, Inc. This file is part of the GNU C Library. This file 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. This file 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 this program. If not, see <https://www.gnu.org/licenses/>. */ /* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc optimizes away the name == NULL test below. */ #define _GL_ARG_NONNULL(params) #include <config.h> /* Specification. */ #include <stdlib.h> #include <errno.h> #if !_LIBC # define __set_errno(ev) ((errno) = (ev)) #endif #include <string.h> #include <unistd.h> #if !_LIBC # define __environ environ #endif #if _LIBC /* This lock protects against simultaneous modifications of 'environ'. */ # include <bits/libc-lock.h> __libc_lock_define_initialized (static, envlock) # define LOCK __libc_lock_lock (envlock) # define UNLOCK __libc_lock_unlock (envlock) #else # define LOCK # define UNLOCK #endif /* In the GNU C library we must keep the namespace clean. */ #ifdef _LIBC # define unsetenv __unsetenv #endif #if _LIBC || !HAVE_UNSETENV int unsetenv (const char *name) { size_t len; char **ep; if (name == NULL || *name == '\0' || strchr (name, '=') != NULL) { __set_errno (EINVAL); return -1; } len = strlen (name); LOCK; ep = __environ; while (*ep != NULL) if (!strncmp (*ep, name, len) && (*ep)[len] == '=') { /* Found it. Remove this pointer by moving later ones back. */ char **dp = ep; do dp[0] = dp[1]; while (*dp++); /* Continue the loop in case NAME appears again. */ } else ++ep; UNLOCK; return 0; } #ifdef _LIBC # undef unsetenv weak_alias (__unsetenv, unsetenv) #endif #else /* HAVE_UNSETENV */ # undef unsetenv # if !HAVE_DECL_UNSETENV # if VOID_UNSETENV extern void unsetenv (const char *); # else extern int unsetenv (const char *); # endif # endif /* Call the underlying unsetenv, in case there is hidden bookkeeping that needs updating beyond just modifying environ. */ int rpl_unsetenv (const char *name) { int result = 0; if (!name || !*name || strchr (name, '=')) { errno = EINVAL; return -1; } while (getenv (name)) # if !VOID_UNSETENV result = # endif unsetenv (name); return result; } #endif /* HAVE_UNSETENV */