Php/docs/function.posix-access

• PHP Manual
• POSIX 函数
• Determine accessibility of a file

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

参见

• posix_get_last_error() - Retrieve the error number set by the last posix function that failed
• posix_strerror() - Retrieve the system error message associated with the given errno