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stream_is_local	stream_notification_callback

Stream Functions	Last updated: Mon, 26 Oct 2026

stream_isatty

(PHP 7 >= 7.2.0, PHP 8)

stream_isatty — Check if a stream is a TTY

Description

function stream_isatty(resource $stream): bool

Determines if stream stream refers to a valid terminal type device. This is a more portable version of posix_isatty(), since it works on Windows systems too.

Parameters

stream

Return Values

Returns true on success or false on failure.

Examples

Example #1 stream_isatty() example

This command can be used to determine if a standard output / standard error stream is redirected to a file.

php -r "var_export(stream_isatty(STDERR));"

The above example will output something similar to:

true

php -r "var_export(stream_isatty(STDERR));" 2>output.txt

The above example will output something similar to:

false

stream_is_local	stream_notification_callback

Stream Functions	Last updated: Mon, 26 Oct 2026