PHP Filesystem Functions

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PHP Filesystem Introduction

The filesystem functions allow you to access and manipulate the filesystem.

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Installation

The filesystem functions are part of the PHP core. There is no installation needed to use these functions.

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Runtime Configuration

The behavior of the filesystem functions is affected by settings in php.ini.
Filesystem configuration options:

Name	Default	Description	Changeable
allow_url_fopen	"1"	Allows fopen()-type functions to work with URLs (available since PHP 4.0.4)	PHP_INI_SYSTEM
user_agent	NULL	Defines the user agent for PHP to send (available since PHP 4.3)	PHP_INI_ALL
default_socket_timeout	"60"	Sets the default timeout, in seconds, for socket based streams (available since PHP 4.3)	PHP_INI_ALL
from	""	Defines the anonymous FTP password (your email address)	PHP_INI_ALL
auto_detect_line_endings	"0"	When set to "1", PHP will examine the data read by fgets() and file() to see if it is using Unix, MS-Dos or Mac line-ending characters (available since PHP 4.3)	PHP_INI_ALL

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Unix / Windows Compatibility

When specifying a path on Unix platforms, the forward slash (/) is used as directory separator. However, on Windows platforms, both forward slash (/) and backslash (\) can be used.

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PHP Filesystem Functions

PHP: indicates the earliest version of PHP that supports the function.

Function	Description	PHP
basename()	Returns the filename component of a path	3
chgrp()	Changes the file group	3
chmod()	Changes the file mode	3
chown()	Changes the file owner	3
clearstatcache()	Clears the file status cache	3
copy()	Copies a file	3
delete()	See unlink() or unset()
dirname()	Returns the directory name component of a path	3
disk_free_space()	Returns the free space of a directory	4
disk_total_space()	Returns the total size of a directory	4
diskfreespace()	Alias of disk_free_space()	3
fclose()	Closes an open file	3
feof()	Tests for end-of-file on an open file	3
fflush()	Flushes buffered output to an open file	4
fgetc()	Returns a character from an open file	3
fgetcsv()	Parses a line from an open file, checking for CSV fields	3
fgets()	Returns a line from an open file	3
fgetss()	Returns a line, with HTML and PHP tags removed, from an open file	3
file()	Reads a file into an array	3
file_exists()	Checks whether or not a file or directory exists	3
file_get_contents()	Reads a file into a string	4
file_put_contents	Writes a string to a file	5
fileatime()	Returns the last access time of a file	3
filectime()	Returns the last change time of a file	3
filegroup()	Returns the group ID of a file	3
fileinode()	Returns the inode number of a file	3
filemtime()	Returns the last modification time of a file	3
fileowner()	Returns the user ID (owner) of a file	3
fileperms()	Returns the permissions of a file	3
filesize()	Returns the file size	3
filetype()	Returns the file type	3
flock()	Locks or releases a file	3
fnmatch()	Matches a filename or string against a specified pattern	4
fopen()	Opens a file or URL	3
fpassthru()	Reads from an open file, until EOF, and writes the result to the output buffer	3
fputcsv()	Formats a line as CSV and writes it to an open file	5
fputs()	Alias of fwrite()	3
fread()	Reads from an open file	3
fscanf()	Parses input from an open file according to a specified format	4
fseek()	Seeks in an open file	3
fstat()	Returns information about an open file	4
ftell()	Returns the current position in an open file	3
ftruncate()	Truncates an open file to a specified length	4
fwrite()	Writes to an open file	3
glob()	Returns an array of filenames / directories matching a specified pattern	4
is_dir()	Checks whether a file is a directory	3
is_executable()	Checks whether a file is executable	3
is_file()	Checks whether a file is a regular file	3
is_link()	Checks whether a file is a link	3
is_readable()	Checks whether a file is readable	3
is_uploaded_file()	Checks whether a file was uploaded via HTTP POST	3
is_writable()	Checks whether a file is writeable	4
is_writeable()	Alias of is_writable()	3
link()	Creates a hard link	3
linkinfo()	Returns information about a hard link	3
lstat()	Returns information about a file or symbolic link	3
mkdir()	Creates a directory	3
move_uploaded_file()	Moves an uploaded file to a new location	4
parse_ini_file()	Parses a configuration file	4
pathinfo()	Returns information about a file path	4
pclose()	Closes a pipe opened by popen()	3
popen()	Opens a pipe	3
readfile()	Reads a file and writes it to the output buffer	3
readlink()	Returns the target of a symbolic link	3
realpath()	Returns the absolute pathname	4
rename()	Renames a file or directory	3
rewind()	Rewinds a file pointer	3
rmdir()	Removes an empty directory	3
set_file_buffer()	Sets the buffer size of an open file	3
stat()	Returns information about a file	3
symlink()	Creates a symbolic link	3
tempnam()	Creates a unique temporary file	3
tmpfile()	Creates a unique temporary file	3
touch()	Sets access and modification time of a file	3
umask()	Changes file permissions for files	3
unlink()	Deletes a file	3

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PHP Filesystem Constants

PHP: indicates the earliest version of PHP that supports the constant.

Constant	Description	PHP
GLOB_BRACE
GLOB_ONLYDIR
GLOB_MARK
GLOB_NOSORT
GLOB_NOCHECK
GLOB_NOESCAPE
PATHINFO_DIRNAME
PATHINFO_BASENAME
PATHINFO_EXTENSION
FILE_USE_INCLUDE_PATH
FILE_APPEND
FILE_IGNORE_NEW_LINES
FILE_SKIP_EMPTY_LINES

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