fix: coding style and file format for all example.

eBook/examples/chapter_12/cat.go

@@ -1,36 +1,35 @@
-package main
-
-import (
-	"os"
-	"io"
-	"fmt"
-	"bufio"
-	"flag"
-)
-
-func cat(r *bufio.Reader) {
-	for {
-		buf, err := r.ReadBytes('\n')
-		if err == io.EOF {
-			break
-		}
-		fmt.Fprintf(os.Stdout, "%s", buf)
-	}
-	return
-}
-
-func main() {
-	flag.Parse()
-	if flag.NArg() == 0 {
-		cat(bufio.NewReader(os.Stdin))
-	}
-	for i := 0; i < flag.NArg(); i++ {
-		f, err := os.Open(flag.Arg(i))
-		if err != nil {
-			fmt.Fprintf(os.Stderr, "%s:error reading from %s: %s\n", os.Args[0], flag.Arg(i), err.Error())
-			continue
-		}
-		cat(bufio.NewReader(f))
-	}
-}
-
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+)
+
+func cat(r *bufio.Reader) {
+	for {
+		buf, err := r.ReadBytes('\n')
+		if err == io.EOF {
+			break
+		}
+		fmt.Fprintf(os.Stdout, "%s", buf)
+	}
+	return
+}
+
+func main() {
+	flag.Parse()
+	if flag.NArg() == 0 {
+		cat(bufio.NewReader(os.Stdin))
+	}
+	for i := 0; i < flag.NArg(); i++ {
+		f, err := os.Open(flag.Arg(i))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s:error reading from %s: %s\n", os.Args[0], flag.Arg(i), err.Error())
+			continue
+		}
+		cat(bufio.NewReader(f))
+	}
+}