posix_access
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
posix_access — Determine accessibility of a file
说明
$filename
, int $flags = 0
) : boolposix_access() checks the user's permission of a file.
参数
-
filename -
The name of the file to be tested.
-
flags -
A mask consisting of one or more of
POSIX_F_OK,POSIX_R_OK,POSIX_W_OKandPOSIX_X_OK.POSIX_R_OK,POSIX_W_OKandPOSIX_X_OKrequest checking whether the file exists and has read, write and execute permissions, respectively.POSIX_F_OKjust 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
示例 #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