const golang.org/x/sys/unix.FD_CLOEXEC

2 uses

	golang.org/x/sys/unix (current package)
		syscall_unix.go#L388: func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }
		zerrors_darwin_amd64.go#L473: 	FD_CLOEXEC                        = 0x1