doc/talks/io2010: handle the errors

R=golang-dev, dsymonds, dsymonds, r
CC=golang-dev
https://golang.org/cl/4771041

diff --git a/doc/talks/io2010/decrypt.go b/doc/talks/io2010/decrypt.go
index 8d21690be034c4b3cbfca35fac3c6b86fa13addc..0a6c006e24731d2f36c0d4641413c18811a4eb1e 100644 (file)
--- a/doc/talks/io2010/decrypt.go
+++ b/doc/talks/io2010/decrypt.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// This code differs from the slides in that it handles errors.
+
 package main
 
 import (
@@ -9,32 +11,75 @@ import (
        "crypto/cipher"
        "compress/gzip"
        "io"
+       "log"
        "os"
 )
 
-func EncryptAndGzip(dstfile, srcfile string, key, iv []byte) {
-       r, _ := os.Open(srcfile)
+func EncryptAndGzip(dstfile, srcfile string, key, iv []byte) os.Error {
+       r, err := os.Open(srcfile)
+       if err != nil {
+               return err
+       }
        var w io.Writer
-       w, _ = os.Create(dstfile)
-       c, _ := aes.NewCipher(key)
+       w, err = os.Create(dstfile)
+       if err != nil {
+               return err
+       }
+       c, err := aes.NewCipher(key)
+       if err != nil {
+               return err
+       }
        w = cipher.StreamWriter{S: cipher.NewOFB(c, iv), W: w}
-       w2, _ := gzip.NewWriter(w)
-       io.Copy(w2, r)
-       w2.Close()
+       w2, err := gzip.NewWriter(w)
+       if err != nil {
+               return err
+       }
+       defer w2.Close()
+       _, err = io.Copy(w2, r)
+       return err
 }
 
-func DecryptAndGunzip(dstfile, srcfile string, key, iv []byte) {
-       f, _ := os.Open(srcfile)
+func DecryptAndGunzip(dstfile, srcfile string, key, iv []byte) os.Error {
+       f, err := os.Open(srcfile)
+       if err != nil {
+               return err
+       }
        defer f.Close()
-       c, _ := aes.NewCipher(key)
+       c, err := aes.NewCipher(key)
+       if err != nil {
+               return err
+       }
        r := cipher.StreamReader{S: cipher.NewOFB(c, iv), R: f}
-       r2, _ := gzip.NewReader(r)
-       w, _ := os.Create(dstfile)
+       r2, err := gzip.NewReader(r)
+       if err != nil {
+               return err
+       }
+       w, err := os.Create(dstfile)
+       if err != nil {
+               return err
+       }
        defer w.Close()
-       io.Copy(w, r2)
+       _, err = io.Copy(w, r2)
+       return err
 }
 
 func main() {
-       EncryptAndGzip("/tmp/passwd.gz", "/etc/passwd", make([]byte, 16), make([]byte, 16))
-       DecryptAndGunzip("/dev/stdout", "/tmp/passwd.gz", make([]byte, 16), make([]byte, 16))
+       err := EncryptAndGzip(
+               "/tmp/passwd.gz",
+               "/etc/passwd",
+               make([]byte, 16),
+               make([]byte, 16),
+       )
+       if err != nil {
+               log.Fatal(err)
+       }
+       err = DecryptAndGunzip(
+               "/dev/stdout",
+               "/tmp/passwd.gz",
+               make([]byte, 16),
+               make([]byte, 16),
+       )
+       if err != nil {
+               log.Fatal(err)
+       }
 }

diff --git a/doc/talks/io2010/encrypt.go b/doc/talks/io2010/encrypt.go
index 56d1dc1b2fe9ec27e0326eb162154dd2e361f2b2..c6508bba15c0a0ab4d19397075507c458156a935 100644 (file)
--- a/doc/talks/io2010/encrypt.go
+++ b/doc/talks/io2010/encrypt.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// This code differs from the slides in that it handles errors.
+
 package main
 
 import (
@@ -9,20 +11,42 @@ import (
        "crypto/cipher"
        "compress/gzip"
        "io"
+       "log"
        "os"
 )
 
-func EncryptAndGzip(dstfile, srcfile string, key, iv []byte) {
-       r, _ := os.Open(srcfile)
+func EncryptAndGzip(dstfile, srcfile string, key, iv []byte) os.Error {
+       r, err := os.Open(srcfile)
+       if err != nil {
+               return err
+       }
        var w io.WriteCloser
-       w, _ = os.Create(dstfile)
+       w, err = os.Create(dstfile)
+       if err != nil {
+               return err
+       }
        defer w.Close()
-       w, _ = gzip.NewWriter(w)
+       w, err = gzip.NewWriter(w)
+       if err != nil {
+               return err
+       }
        defer w.Close()
-       c, _ := aes.NewCipher(key)
-       io.Copy(cipher.StreamWriter{S: cipher.NewOFB(c, iv), W: w}, r)
+       c, err := aes.NewCipher(key)
+       if err != nil {
+               return err
+       }
+       _, err = io.Copy(cipher.StreamWriter{S: cipher.NewOFB(c, iv), W: w}, r)
+       return err
 }
 
 func main() {
-       EncryptAndGzip("/tmp/passwd.gz", "/etc/passwd", make([]byte, 16), make([]byte, 16))
+       err := EncryptAndGzip(
+               "/tmp/passwd.gz",
+               "/etc/passwd",
+               make([]byte, 16),
+               make([]byte, 16),
+       )
+       if err != nil {
+               log.Fatal(err)
+       }
 }