Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Filesystem and Streams Configuration Options
Name Default Changeable Changelog
allow_url_fopen "1" INI_SYSTEM  
allow_url_include "0" INI_SYSTEM Deprecated as of PHP 7.4.0.
user_agent NULL INI_ALL  
default_socket_timeout "60" INI_ALL  
from "" INI_ALL  
auto_detect_line_endings "0" INI_ALL Deprecated as of PHP 8.1.0.
sys_temp_dir "" INI_SYSTEM  

Here's a short explanation of the configuration directives.

allow_url_fopen bool

This option enables the URL-aware fopen wrappers that enable accessing URL object like files. Default wrappers are provided for the access of remote files using the ftp or http protocol, some extensions like zlib may register additional wrappers.

allow_url_include bool

This option allows the use of URL-aware fopen wrappers with the following functions: include, include_once, require, require_once.

Note:

This setting requires allow_url_fopen to be on.

user_agent string

Define the user agent for PHP to send.

default_socket_timeout int

Default timeout (in seconds) for socket based streams. Specifying a negative value means an infinite timeout.

from string

The email address to be used on unauthenticated FTP connections and as the value of From header for HTTP connections, when using the ftp and http wrappers, respectively.

auto_detect_line_endings bool

When turned on, PHP will examine the data read by fgets and file to see if it is using Unix, MS-Dos or Macintosh line-ending conventions.

This enables PHP to interoperate with Macintosh systems, but defaults to Off, as there is a very small performance penalty when detecting the EOL conventions for the first line, and also because people using carriage-returns as item separators under Unix systems would experience non-backwards-compatible behaviour.

sys_temp_dir string