Add --syslog flag to optionally log to syslog on capable platforms

fs/redirect_stderr_windows.go

@@ -0,0 +1,39 @@
+// Log the panic under windows to the log file
+//
+// Code from minix, via
+//
+// http://play.golang.org/p/kLtct7lSUg
+
+// +build windows
+
+package fs
+
+import (
+	"log"
+	"os"
+	"syscall"
+)
+
+var (
+	kernel32         = syscall.MustLoadDLL("kernel32.dll")
+	procSetStdHandle = kernel32.MustFindProc("SetStdHandle")
+)
+
+func setStdHandle(stdhandle int32, handle syscall.Handle) error {
+	r0, _, e1 := syscall.Syscall(procSetStdHandle.Addr(), 2, uintptr(stdhandle), uintptr(handle), 0)
+	if r0 == 0 {
+		if e1 != 0 {
+			return error(e1)
+		}
+		return syscall.EINVAL
+	}
+	return nil
+}
+
+// redirectStderr to the file passed in
+func redirectStderr(f *os.File) {
+	err := setStdHandle(syscall.STD_ERROR_HANDLE, syscall.Handle(f.Fd()))
+	if err != nil {
+		log.Fatalf("Failed to redirect stderr to file: %v", err)
+	}
+}