isTTY checks whether the given writer is a *os.File TTY.
(w io.Writer)
| 364 | |
| 365 | // isTTY checks whether the given writer is a *os.File TTY. |
| 366 | func isTTY(w io.Writer) bool { |
| 367 | if w == forceColorWriter { |
| 368 | return true |
| 369 | } |
| 370 | // SyscallConn is safe during file close. |
| 371 | if sc, ok := w.(interface { |
| 372 | SyscallConn() (syscall.RawConn, error) |
| 373 | }); ok { |
| 374 | conn, err := sc.SyscallConn() |
| 375 | if err != nil { |
| 376 | return false |
| 377 | } |
| 378 | var isTerm bool |
| 379 | err = conn.Control(func(fd uintptr) { |
| 380 | isTerm = term.IsTerminal(int(fd)) |
| 381 | }) |
| 382 | if err != nil { |
| 383 | return false |
| 384 | } |
| 385 | return isTerm |
| 386 | } |
| 387 | // Fallback to unsafe Fd. |
| 388 | f, ok := w.(interface{ Fd() uintptr }) |
| 389 | return ok && term.IsTerminal(int(f.Fd())) |
| 390 | } |
| 391 | |
| 392 | func shouldColor(w io.Writer) bool { |
| 393 | return isTTY(w) || os.Getenv("FORCE_COLOR") != "" |