Detect if stdin is a tty device (terminal) or pipe in PHP?

Question

I wrote a php script. I want it show help message when called with standard input connected to a tty device (terminal) before reading and executing interactively, but dont show when called with a file or stream from pipe as standard input.

Is there a way to detect this from PHP?

Answer 1

Use posix_isatty.

This function accepts both a file descriptor (an integer) and a PHP stream. If it receives a PHP stream, it automatically attempts to cast it in order to obtain a file descriptor and use it instead.