echo: added delimiter option.

echo/echo.go

@@ -6,19 +6,26 @@ import (
 	"flag"
 )
 
+var(
+	del string
+	eol = "\n"
+)
+
 func Run(args []string) int {
 	var nflag bool
 	flagSet := flag.NewFlagSet(args[0], flag.ExitOnError)
 	flagSet.BoolVar(&nflag, "n", false, "Do not print new line character.")
+	flagSet.StringVar(&del, "d", " ", "Delimiter of arguments")
 	flagSet.Parse(args[1:])
 	args = flagSet.Args()
 	l := len(args) - 1
 	for i, s := range args {
 		fmt.Print(s)
-		if i!=l { fmt.Print(" ") }
+		if i!=l { fmt.Print(del) }
 	}
 	if !nflag {
-		fmt.Print("\n")
+		fmt.Print(eol)
 	}
+
 	return 0
 }