added dependency github.com/sevlyar/go-daemon

vendor/github.com/sevlyar/go-daemon/lock_file_unix.go

@@ -0,0 +1,40 @@
+// +build dragonfly freebsd linux netbsd openbsd plan9 solaris
+
+package daemon
+
+import (
+	"fmt"
+	"syscall"
+)
+
+func lockFile(fd uintptr) error {
+	err := syscall.Flock(int(fd), syscall.LOCK_EX|syscall.LOCK_NB)
+	if err == syscall.EWOULDBLOCK {
+		err = ErrWouldBlock
+	}
+	return err
+}
+
+func unlockFile(fd uintptr) error {
+	err := syscall.Flock(int(fd), syscall.LOCK_UN)
+	if err == syscall.EWOULDBLOCK {
+		err = ErrWouldBlock
+	}
+	return err
+}
+
+const pathMax = 0x1000
+
+func getFdName(fd uintptr) (name string, err error) {
+	path := fmt.Sprintf("/proc/self/fd/%d", int(fd))
+	// We use predefined pathMax const because /proc directory contains special files
+	// so that unable to get correct size of pseudo-symlink through lstat.
+	// please see notes and example for readlink syscall:
+	// http://man7.org/linux/man-pages/man2/readlink.2.html#NOTES
+	buf := make([]byte, pathMax)
+	var n int
+	if n, err = syscall.Readlink(path, buf); err == nil {
+		name = string(buf[:n])
+	}
+	return
+}