Added extra check if fileContainsNullChar returns err; pass filename to it instead of file

kg/helpers.go

@@ -32,13 +32,21 @@ func genRange[T character](start, end T) []T {
 }
 
 // Returns whether or not the given file contains a NULL character
-func fileContainsNullChar(file *os.File) bool {
+func fileContainsNullChar(filename string) (bool, error) {
+	file, err := os.Open(filename)
+	if err != nil {
+		return true, err
+	}
+	defer file.Close()
 	scanner := bufio.NewScanner(file)
 	for scanner.Scan() {
 		line := scanner.Text()
 		if strings.Contains(line, "\000") {
-			return true
+			return true, nil
 		}
 	}
-	return false
+	if err := scanner.Err(); err != nil {
+		return true, err
+	}
+	return false, nil
 }

kg/main.go

@@ -91,6 +91,7 @@ func main() {
 		inputFilenames := flag.Args()[1:]
 		for _, inputFilename := range inputFilenames {
 			inputFile, err := os.Open(inputFilename)
+			defer inputFile.Close()
 			if err != nil {
 				fmt.Printf("%s: %s: No such file or directory\n", os.Args[0], inputFilename)
 			} else {
@@ -102,8 +103,14 @@ func main() {
 					if fileStat.Mode().IsDir() {
 						fmt.Printf("%s: %s: Is a directory\n", os.Args[0], inputFilename)
 					} else {
-						if fileContainsNullChar(inputFile) {
+						var nullCharPresent bool
-							fmt.Printf("%s: %s: Is a binary file\n", os.Args[0], inputFilename)
+						if nullCharPresent, err = fileContainsNullChar(inputFilename); nullCharPresent {
+							if err != nil {
+								fmt.Printf("%v\n", err)
+								os.Exit(1)
+							} else {
+								fmt.Printf("%s: %s: Is a binary file\n", os.Args[0], inputFilename)
+							}
 						} else {
 							inputFiles = append(inputFiles, inputFile)
 						}