PHP Filesystem Introduction
The filesystem functions allow you to access and manipulate the filesystem.
Installation
The filesystem functions are part of the PHP core. There is no installation needed to use these functions.
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 |
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.
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 |
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 |