file_exists
(PHP 4, PHP 5)
file_exists — Checks whether a file or directory exists
說明
Checks whether a file or directory exists.
參數
- filename
-
Path to the file or directory.
On windows, use //computername/share/filename or \\computername\share\filename to check files on network shares.
Return值
Returns TRUE if the file or directory specified by filename exists; FALSE otherwise.
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.
範例
Example#1 Testing whether a file exists
<?php
$filename = '/path/to/foo.txt';
if (file_exists($filename)) {
echo "The file $filename exists";
} else {
echo "The file $filename does not exist";
}
?>
註釋
Note: 本函式的結果會被存入緩衝區。詳情參見 clearstatcache()。
自 PHP 5.0.0 起本函式也可被某些 URL wrapper 使用。參考List of Supported Protocols/Wrappers 來看哪些 wrapper 支援 stat() 系列函式的功能。