github.com/bir3/gocompiler@v0.9.2202/src/xvendor/golang.org/x/sys/unix/fcntl.go (about) 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 //go:build dragonfly || freebsd || linux || netbsd 6 7 package unix 8 9 import "unsafe" 10 11 // fcntl64Syscall is usually SYS_FCNTL, but is overridden on 32-bit Linux 12 // systems by fcntl_linux_32bit.go to be SYS_FCNTL64. 13 var fcntl64Syscall uintptr = SYS_FCNTL 14 15 func fcntl(fd int, cmd, arg int) (int, error) { 16 valptr, _, errno := Syscall(fcntl64Syscall, uintptr(fd), uintptr(cmd), uintptr(arg)) 17 var err error 18 if errno != 0 { 19 err = errno 20 } 21 return int(valptr), err 22 } 23 24 // FcntlInt performs a fcntl syscall on fd with the provided command and argument. 25 func FcntlInt(fd uintptr, cmd, arg int) (int, error) { 26 return fcntl(int(fd), cmd, arg) 27 } 28 29 // FcntlFlock performs a fcntl syscall for the F_GETLK, F_SETLK or F_SETLKW command. 30 func FcntlFlock(fd uintptr, cmd int, lk *Flock_t) error { 31 _, _, errno := Syscall(fcntl64Syscall, fd, uintptr(cmd), uintptr(unsafe.Pointer(lk))) 32 if errno == 0 { 33 return nil 34 } 35 return errno 36 }