| /* Copyright (C) 1991, 1994, 1997-1998, 2000, 2003-2020 Free Software |
| Foundation, Inc. |
| |
| NOTE: The canonical source of this file is maintained with the GNU C |
| Library. Bugs can be reported to bug-glibc@prep.ai.mit.edu. |
| |
| 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 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 <https://www.gnu.org/licenses/>. */ |
| |
| #include <config.h> |
| |
| /* Specification. */ |
| #include <stdlib.h> |
| |
| #include <stddef.h> |
| |
| /* Include errno.h *after* sys/types.h to work around header problems |
| on AIX 3.2.5. */ |
| #include <errno.h> |
| #ifndef __set_errno |
| # define __set_errno(ev) ((errno) = (ev)) |
| #endif |
| |
| #include <string.h> |
| #include <unistd.h> |
| |
| #if defined _WIN32 && ! defined __CYGWIN__ |
| # define WIN32_LEAN_AND_MEAN |
| # include <windows.h> |
| #endif |
| |
| #if _LIBC |
| # if HAVE_GNU_LD |
| # define environ __environ |
| # else |
| extern char **environ; |
| # endif |
| #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 |
| |
| static int |
| _unsetenv (const char *name) |
| { |
| size_t len; |
| #if !HAVE_DECL__PUTENV |
| char **ep; |
| #endif |
| |
| if (name == NULL || *name == '\0' || strchr (name, '=') != NULL) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| |
| len = strlen (name); |
| |
| #if HAVE_DECL__PUTENV |
| { |
| int putenv_result, putenv_errno; |
| char *name_ = malloc (len + 2); |
| memcpy (name_, name, len); |
| name_[len] = '='; |
| name_[len + 1] = 0; |
| putenv_result = _putenv (name_); |
| putenv_errno = errno; |
| free (name_); |
| __set_errno (putenv_errno); |
| return putenv_result; |
| } |
| #else |
| |
| 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; |
| #endif |
| } |
| |
| |
| /* Put STRING, which is of the form "NAME=VALUE", in the environment. |
| If STRING contains no '=', then remove STRING from the environment. */ |
| int |
| putenv (char *string) |
| { |
| const char *name_end = strchr (string, '='); |
| char **ep; |
| |
| if (name_end == NULL) |
| { |
| /* Remove the variable from the environment. */ |
| return _unsetenv (string); |
| } |
| |
| #if HAVE_DECL__PUTENV |
| /* Rely on _putenv to allocate the new environment. If other |
| parts of the application use _putenv, the !HAVE_DECL__PUTENV code |
| would fight over who owns the environ vector, causing a crash. */ |
| if (name_end[1]) |
| return _putenv (string); |
| else |
| { |
| /* _putenv ("NAME=") unsets NAME, so invoke _putenv ("NAME= ") |
| to allocate the environ vector and then replace the new |
| entry with "NAME=". */ |
| int putenv_result, putenv_errno; |
| char *name_x = malloc (name_end - string + sizeof "= "); |
| if (!name_x) |
| return -1; |
| memcpy (name_x, string, name_end - string + 1); |
| name_x[name_end - string + 1] = ' '; |
| name_x[name_end - string + 2] = 0; |
| putenv_result = _putenv (name_x); |
| putenv_errno = errno; |
| for (ep = environ; *ep; ep++) |
| if (strcmp (*ep, name_x) == 0) |
| { |
| *ep = string; |
| break; |
| } |
| # if defined _WIN32 && ! defined __CYGWIN__ |
| if (putenv_result == 0) |
| { |
| /* _putenv propagated "NAME= " into the subprocess environment; |
| fix that by calling SetEnvironmentVariable directly. */ |
| name_x[name_end - string] = 0; |
| putenv_result = SetEnvironmentVariable (name_x, "") ? 0 : -1; |
| putenv_errno = ENOMEM; /* ENOMEM is the only way to fail. */ |
| } |
| # endif |
| free (name_x); |
| __set_errno (putenv_errno); |
| return putenv_result; |
| } |
| #else |
| for (ep = environ; *ep; ep++) |
| if (strncmp (*ep, string, name_end - string) == 0 |
| && (*ep)[name_end - string] == '=') |
| break; |
| |
| if (*ep) |
| *ep = string; |
| else |
| { |
| static char **last_environ = NULL; |
| size_t size = ep - environ; |
| char **new_environ = malloc ((size + 2) * sizeof *new_environ); |
| if (! new_environ) |
| return -1; |
| new_environ[0] = string; |
| memcpy (new_environ + 1, environ, (size + 1) * sizeof *new_environ); |
| free (last_environ); |
| last_environ = new_environ; |
| environ = new_environ; |
| } |
| |
| return 0; |
| #endif |
| } |