call os.Exit(2) in case the parameter for -n is negative.

sassy · Aug 15, 2015 · a52a5ca · a52a5ca
1 parent 7036af5
commit a52a5ca
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/main.go b/main.go
@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"github.com/PuerkitoBio/goquery"
+	"os"
 	"regexp"
 	"strconv"
 	"time"
@@ -90,6 +91,11 @@ func main() {
 	flag.IntVar(&numOfResult, "n", DefaultNumOfResultToShow, "specify amount of result.")
 	flag.Parse()
 
+	if numOfResult < 0 {
+		fmt.Fprintf(os.Stderr, "parameter for -n must be greater than 0.\n")
+		os.Exit(2)
+	}
+
 	hour, minute := departureTime(departure)
 	timetable := createTimetable(getSelector())