update book code

eBook/examples/chapter_12/fileinput.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+)
+
+func main() {
+	// var inputFile *os.File
+	// var inputError, readerError os.Error
+	// var inputReader *bufio.Reader
+	// var inputString string
+
+	inputFile, inputError := os.Open("input.dat")
+	if inputError != nil {
+		fmt.Printf("An error occurred on opening the inputfile\n" + 
+		           "Does the file exist?\n" + 
+			       "Have you got acces to it?\n")
+		return // exit the function on error
+	}
+	defer inputFile.Close()
+
+	inputReader := bufio.NewReader(inputFile)
+
+	for {
+		inputString, readerError := inputReader.ReadString('\n')
+		if readerError == io.EOF {
+			return // error or EOF
+		}
+		fmt.Printf("The input was: %s", inputString)
+	}
+}