(PHP 4, PHP 5, PHP 7)
putenv — Sets the value of an environment variable
$setting) : bool
setting to the server environment. The
environment variable will only exist for the duration of the current
request. At the end of the request the environment is restored to its
Setting certain environment variables may be a potential security breach.
safe_mode_allowed_env_vars directive contains a
comma-delimited list of prefixes. In Safe Mode, the user may only alter
environment variables whose names begin with the prefixes supplied by
this directive. By default, users will only be able to set environment
variables that begin with
PHP_FOO=BAR). Note: if this directive is empty, PHP
will let the user modify ANY environment variable!
safe_mode_protected_env_vars directive contains a
comma-delimited list of environment variables, that the end user won't be
able to change using putenv(). These variables will
be protected even if
safe_mode_allowed_env_vars is set
to allow to change them.
The setting, like
TRUE on success or
FALSE on failure.
Example #1 Setting an environment variable
safe_mode_protected_env_vars directives only take
effect when safe_mode is