1// Copyright 2014 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// +build darwin dragonfly freebsd linux netbsd openbsd 6 7package unix 8 9import "unsafe" 10 11// fcntl64Syscall is usually SYS_FCNTL, but is overridden on 32-bit Linux 12// systems by flock_linux_32bit.go to be SYS_FCNTL64. 13var fcntl64Syscall uintptr = SYS_FCNTL 14 15// FcntlInt performs a fcntl syscall on fd with the provided command and argument. 16func FcntlInt(fd uintptr, cmd, arg int) (int, error) { 17 valptr, _, errno := Syscall(fcntl64Syscall, fd, uintptr(cmd), uintptr(arg)) 18 var err error 19 if errno != 0 { 20 err = errno 21 } 22 return int(valptr), err 23} 24 25// FcntlFlock performs a fcntl syscall for the F_GETLK, F_SETLK or F_SETLKW command. 26func FcntlFlock(fd uintptr, cmd int, lk *Flock_t) error { 27 _, _, errno := Syscall(fcntl64Syscall, fd, uintptr(cmd), uintptr(unsafe.Pointer(lk))) 28 if errno == 0 { 29 return nil 30 } 31 return errno 32} 33