blob: db25fcca98597cb389ff356c5ac144c16030d0a3 [file] [log] [blame]
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build dragonfly freebsd linux netbsd openbsd
package unix
import "syscall"
// FcntlSyscall is the number for the fcntl system call. This is
// usually SYS_FCNTL, but can be overridden to SYS_FCNTL64.
var FcntlSyscall uintptr = syscall.SYS_FCNTL
func IsNonblock(fd int) (nonblocking bool, err error) {
flag, _, e1 := syscall.Syscall(FcntlSyscall, uintptr(fd), uintptr(syscall.F_GETFL), 0)
if e1 != 0 {
return false, e1
}
return flag&syscall.O_NONBLOCK != 0, nil
}