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Diffstat (limited to 'gltests/unsetenv.c')
-rw-r--r-- | gltests/unsetenv.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/gltests/unsetenv.c b/gltests/unsetenv.c new file mode 100644 index 0000000..16b50d1 --- /dev/null +++ b/gltests/unsetenv.c @@ -0,0 +1,127 @@ +/* Copyright (C) 1992, 1995-2002, 2005-2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc + optimizes away the name == NULL test below. */ +#define _GL_ARG_NONNULL(params) + +/* 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 */ |