update book code

eBook/exercises/chapter_12/remove_3till5char.go

@@ -0,0 +1,37 @@
+// remove_first6char.go
+package main
+
+import (
+	"fmt"
+	"io"
+	"bufio"
+	"os"
+)
+
+func main() {
+	inputFile, _ := os.Open("goprogram")
+	outputFile, _ := os.OpenFile("goprogramT", os.O_WRONLY|os.O_CREATE, 0666)
+	defer inputFile.Close()
+	defer outputFile.Close()
+	inputReader := bufio.NewReader(inputFile)
+	outputWriter := bufio.NewWriter(outputFile)
+	for {
+		// inputString, readerError := inputReader.ReadString('\n')
+		inputString, _, readerError := inputReader.ReadLine()
+		if readerError == io.EOF {
+			fmt.Println("EOF")
+			break
+		}
+		//fmt.Printf("The input was: --%s--", inputString)
+		outputString := string([]byte(inputString)[2:5]) + "\r\n"
+		//fmt.Printf("The output was: --%s--", outputString)
+		_, err := outputWriter.WriteString(outputString)
+		//fmt.Printf("Number of bytes written %d\n", n)
+		if (err != nil) {
+			fmt.Println(err)
+			return
+		}
+	}
+	outputWriter.Flush()
+	fmt.Println("Conversion done")
+}