posix_access

(PHP 5 >= 5.1.0, PHP 7)

posix_access — Determine accessibility of a file

说明

posix_access ( string $file [, int $mode = POSIX_F_OK ] ) : bool

posix_access() checks the user's permission of a file.

参数

file

The name of the file to be tested.

mode

A mask consisting of one or more of POSIX_F_OK, POSIX_R_OK, POSIX_W_OK and POSIX_X_OK.

POSIX_R_OK, POSIX_W_OK and POSIX_X_OK request checking whether the file exists and has read, write and execute permissions, respectively. POSIX_F_OK just requests checking for the existence of the file.

返回值

成功时返回 TRUE， 或者在失败时返回 FALSE。

范例

Example #1 posix_access() example

This example will check if the $file is readable and writable, otherwise will print an error message.

<?php

$file = 'some_file';

if (posix_access($file, POSIX_R_OK | POSIX_W_OK)) {
    echo 'The file is readable and writable!';

} else {
    $error = posix_get_last_error();

    echo "Error $error: " . posix_strerror($error);
}

?>

注释

Note: 当启用 安全模式时， PHP 会检查被操作的文件或目录是否与被执行的脚本有相同的 UID（所有者）。

参见