No external libraries are needed to build this extension, but if you want PHP to support LFS (large files) on Linux, then you need to have a recent glibc and you need compile PHP with the following compiler flags: -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64.
There is no installation needed to use these functions; they are part of the PHP core.
The behaviour of these functions is affected by settings in php.ini.
Table 1. Filesystem and Streams Configuration Options
| Name | Default | Changeable | Changelog |
|---|---|---|---|
| allow_url_fopen | "1" | PHP_INI_SYSTEM | PHP_INI_ALL in PHP <= 4.3.4. Available since PHP 4.0.4. |
| user_agent | NULL | PHP_INI_ALL | Available since PHP 4.3.0. |
| default_socket_timeout | "60" | PHP_INI_ALL | Available since PHP 4.3.0. |
| from | "" | PHP_INI_ALL | |
| auto_detect_line_endings | "0" | PHP_INI_ALL | Available since PHP 4.3.0. |
Here's a short explanation of the configuration directives.
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.
Note: This setting can only be set in php.ini due to security reasons.
Note: This option was introduced immediately after the release of version 4.0.3. For versions up to and including 4.0.3 you can only disable this feature at compile time by using the configuration switch --disable-url-fopen-wrapper.
| Warning |
On Windows versions prior to PHP 4.3.0, the following functions do not support remote file accessing: include(), include_once(), require(), require_once() and the imagecreatefromXXX functions in the Reference LVIII, Image Functions extension. |
Define the user agent for PHP to send.
Default timeout (in seconds) for socket based streams.
Note: This configuration option was introduced in PHP 4.3.0
Define the anonymous ftp password (your email address).
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.
Note: This configuration option was introduced in PHP 4.3.0
The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
For related functions, see also the Directory and Program Execution sections.
For a list and explanation of the various URL wrappers that can be used as remote files, see also Appendix M.