Read file

examples/error.feature

@@ -3,3 +3,8 @@ Feature: Error
     Given a file named "foo.md" with ""
     When I run `linkcheck`
     Then the exit status should be 1
+
+  Scenario: Fail with a non-existent file
+    Given a file named "foo.md" with ""
+    When I run `linkcheck bar.md`
+    Then the exit status should be 1

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 
 	docopt "github.com/docopt/docopt-go"
@@ -15,7 +16,13 @@ func main() {
 		}
 	}()
 
-	getArgs()
+	args := getArgs()
+
+	_, err := ioutil.ReadFile(args["<filename>"].(string))
+
+	if err != nil {
+		panic(err)
+	}
 }
 
 func getArgs() map[string]interface{} {