XXXVII. Filesystem Functions


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.

Runtime Configuration

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

Table 1. Filesystem and Streams Configuration Options

allow_url_fopen"1"PHP_INI_SYSTEMPHP_INI_ALL in PHP <= 4.3.4. Available since PHP 4.0.4.
user_agentNULLPHP_INI_ALLAvailable since PHP 4.3.0.
default_socket_timeout"60"PHP_INI_ALLAvailable since PHP 4.3.0.
auto_detect_line_endings"0"PHP_INI_ALLAvailable since PHP 4.3.0.

Here's a short explanation of the configuration directives.

allow_url_fopen boolean

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.


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 LIII, Image Functions extension.

user_agent string

Define the user agent for PHP to send.

default_socket_timeout integer

Default timeout (in seconds) for socket based streams.

Note: This configuration option was introduced in PHP 4.3.0

from string

Define the anonymous ftp password (your email address).

auto_detect_line_endings boolean

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

Predefined Constants

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.

GLOB_BRACE (integer)

GLOB_ONLYDIR (integer)

GLOB_MARK (integer)

GLOB_NOSORT (integer)

GLOB_NOCHECK (integer)






FILE_APPEND (integer)



See Also

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 L.

Table of Contents
basename -- Returns filename component of path
chgrp -- Changes file group
chmod -- Changes file mode
chown -- Changes file owner
clearstatcache -- Clears file status cache
copy -- Copies file
delete -- See unlink() or unset()
dirname -- Returns directory name component of path
disk_free_space -- Returns available space in directory
disk_total_space -- Returns the total size of a directory
diskfreespace -- Alias of disk_free_space()
fclose -- Closes an open file pointer
feof -- Tests for end-of-file on a file pointer
fflush -- Flushes the output to a file
fgetc -- Gets character from file pointer
fgetcsv -- Gets line from file pointer and parse for CSV fields
fgets -- Gets line from file pointer
fgetss -- Gets line from file pointer and strip HTML tags
file_exists -- Checks whether a file or directory exists
file_get_contents -- Reads entire file into a string
file_put_contents -- Write a string to a file
file -- Reads entire file into an array
fileatime -- Gets last access time of file
filectime -- Gets inode change time of file
filegroup -- Gets file group
fileinode -- Gets file inode
filemtime -- Gets file modification time
fileowner -- Gets file owner
fileperms -- Gets file permissions
filesize -- Gets file size
filetype -- Gets file type
flock -- Portable advisory file locking
fnmatch -- Match filename against a pattern
fopen -- Opens file or URL
fpassthru -- Output all remaining data on a file pointer
fputcsv --  Format line as CSV and write to file pointer
fputs -- Alias of fwrite()
fread -- Binary-safe file read
fscanf -- Parses input from a file according to a format
fseek -- Seeks on a file pointer
fstat -- Gets information about a file using an open file pointer
ftell -- Tells file pointer read/write position
ftruncate -- Truncates a file to a given length
fwrite -- Binary-safe file write
glob -- Find pathnames matching a pattern
is_dir -- Tells whether the filename is a directory
is_executable -- Tells whether the filename is executable
is_file -- Tells whether the filename is a regular file
is_link -- Tells whether the filename is a symbolic link
is_readable -- Tells whether the filename is readable
is_uploaded_file -- Tells whether the file was uploaded via HTTP POST
is_writable -- Tells whether the filename is writable
is_writeable -- Alias of is_writable()
link -- Create a hard link
linkinfo -- Gets information about a link
lstat -- Gives information about a file or symbolic link
mkdir -- Makes directory
move_uploaded_file -- Moves an uploaded file to a new location
parse_ini_file -- Parse a configuration file
pathinfo -- Returns information about a file path
pclose -- Closes process file pointer
popen -- Opens process file pointer
readfile -- Outputs a file
readlink -- Returns the target of a symbolic link
realpath -- Returns canonicalized absolute pathname
rename -- Renames a file or directory
rewind -- Rewind the position of a file pointer
rmdir -- Removes directory
set_file_buffer -- Alias of stream_set_write_buffer()
stat -- Gives information about a file
symlink -- Creates a symbolic link
tempnam -- Create file with unique file name
tmpfile -- Creates a temporary file
touch -- Sets access and modification time of file
umask -- Changes the current umask
unlink -- Deletes a file