posix_access
(PHP 5 >= 5.1.0)
posix_access — Determine accessibility of a file
说明
bool posix_access ( string $file [, int $mode = POSIX_F_OK ] )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
- 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
