# posix_isatty

(PHP 4, PHP 5, PHP 7)

posix_isatty — Determine if a file descriptor is an interactive terminal

### 说明

posix_isatty ( mixed `$fd` ) : bool

Determines if the file descriptor `fd` refers to a valid terminal type device.

### 参数

`fd`

  The file descriptor, which is expected to be either a file resource or an integer. An integer will be assumed to be a file descriptor that can be passed directly to the underlying system call.

  In almost all cases, you will want to provide a file resource.

### 返回值

Returns `TRUE` if `fd` is an open descriptor connected to a terminal and `FALSE` otherwise.

### 参见

- posix_ttyname() - Determine terminal device name
- stream_isatty() - Check if a stream is a TTY