tty

tty Package

The tty package provides TTY (terminal) detection utilities.

Overview

This package exposes two simple functions for checking whether the standard output or error streams are connected to a real terminal. The detection uses golang.org/x/term, which is the same library used by the spinner and progress-bar components in this codebase.

On WebAssembly targets (js/wasm) the package provides stub implementations that always return false, since WASM environments do not have real TTY file descriptors.

Functions

IsStdoutTerminal() bool

Returns true if stdout (os.Stdout) is connected to a terminal.

import "github.com/github/gh-aw/pkg/tty"

if tty.IsStdoutTerminal() {
    // Safe to emit colored or animated output to stdout
}

IsStderrTerminal() bool

Returns true if stderr (os.Stderr) is connected to a terminal.

if tty.IsStderrTerminal() {
    // Safe to emit colored or animated output to stderr
}

Design Notes

• Terminal detection is evaluated at call time, not cached. This is intentional: the streams could be redirected between calls in some testing scenarios.
• The WASM stub (tty_wasm.go) always returns false so that components built for the browser never attempt to use ANSI escape codes.
• Prefer this package over calling term.IsTerminal directly to keep the TTY detection logic centralized and easily testable.
• Components that need to adapt output for terminals (spinners, progress bars, colored messages) should call IsStderrTerminal() rather than checking os.Stderr directly.