First import

isatty_darwin.go

@@ -0,0 +1,16 @@
+// +build darwin
+
+package isatty
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+const ioctlReadTermios = syscall.TIOCGETA
+
+func IsTerminal(fd int) bool {
+	var termios syscall.Termios
+	_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlReadTermios, uintptr(unsafe.Pointer(&termios)), 0, 0, 0)
+	return err == 0
+}

isatty_linux.go

@@ -0,0 +1,16 @@
+// +build linux
+
+package isatty
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+const ioctlReadTermios = syscall.TCGETS
+
+func IsTerminal(fd int) bool {
+	var termios syscall.Termios
+	_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlReadTermios, uintptr(unsafe.Pointer(&termios)), 0, 0, 0)
+	return err == 0
+}

isatty_windows.go

@@ -0,0 +1,17 @@
+// +build windows
+
+package isatty
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+var kernel32 = syscall.NewLazyDLL("kernel32.dll")
+var procGetConsoleMode = kernel32.NewProc("GetConsoleMode")
+
+func IsTerminal(fd int) bool {
+	var st uint32
+	r, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, uintptr(fd), uintptr(unsafe.Pointer(&st)), 0)
+	return r != 0 && e == 0
+}