posix_access
(PHP 5 >= 5.1.0)
posix_access — Determine accessibility of a file
Описание
posix_access() checks the user's permission of a file.
Список параметров
- 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. Defaults to POSIX_F_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.
Возвращаемые значения
Возвращает TRUE в случае успешного завершения или FALSE в случае возникновения ошибки.
Примеры
Пример #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);
}
?>
Примечания
Замечание: Когда опция safe mode включена, PHP проверяет, имеют ли файлы/каталоги, с которыми вы собираетесь работать, такой же UID (владельца), как и выполняемый скрипт.
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Расширения для управления процессами программ
- POSIX
- posix_access
- posix_ctermid
- posix_errno
- posix_get_last_error
- posix_getcwd
- posix_getegid
- posix_geteuid
- posix_getgid
- posix_getgrgid
- posix_getgrnam
- posix_getgroups
- posix_getlogin
- posix_getpgid
- posix_getpgrp
- posix_getpid
- posix_getppid
- posix_getpwnam
- posix_getpwuid
- posix_getrlimit
- posix_getsid
- posix_getuid
- posix_initgroups
- posix_isatty
- posix_kill
- posix_mkfifo
- posix_mknod
- posix_setegid
- posix_seteuid
- posix_setgid
- posix_setpgid
- posix_setrlimit
- posix_setsid
- posix_setuid
- posix_strerror
- posix_times
- posix_ttyname
- posix_uname
Коментарии
It should be noted that this function performs access checks based on the real UID and real GID of the process running PHP. These aren't necessarily the same as the effective UID and GID.
In other words, it may well be that access() returns “true” for a particular permission, but an fopen() operation which requires the same permission will fail, and vice versa.
Keep that in mind if you use access() for such checks.