Checks whether a file or directory exists
file_exists ( string $filename ) : bool
Path to the file or directory.
On windows, use //computername/share/filename or \computername\share\filename to check files on network shares.
Returns TRUE if the file or directory specified by filename exists; FALSE otherwise.
Note: This function will return FALSE for symlinks pointing to non-existing files.
Warning: This function returns FALSE for files inaccessible due to safe mode restrictions. However these files still can be included if they are located in safe_mode_include_dir.
Note: The check is done using the real UID/GID instead of the effective one.
Note: Because PHP's integer type is signed and many platforms use 32bit integers, some filesystem functions may return unexpected results for files which are larger than 2GB.