crypto/md5, crypto/sha1, crypto/sha256: add examples for checksumming a file

Updates #16360.

Change-Id: I75714d2b5f095fe39fd81edfa6dd9e44d7c44da1
Reviewed-on: https://go-review.googlesource.com/29375
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/crypto/md5/example_test.go b/src/crypto/md5/example_test.go
index d47bb4570c9ad34a35ebe8efaf46eb5e39b9ac1f..af8c1bfd65a8059dffd0549d9eaccefac5641771 100644 (file)
--- a/src/crypto/md5/example_test.go
+++ b/src/crypto/md5/example_test.go
@@ -8,6 +8,8 @@ import (
        "crypto/md5"
        "fmt"
        "io"
+       "log"
+       "os"
 )
 
 func ExampleNew() {
@@ -23,3 +25,18 @@ func ExampleSum() {
        fmt.Printf("%x", md5.Sum(data))
        // Output: b0804ec967f48520697662a204f5fe72
 }
+
+func ExampleNew_file() {
+       f, err := os.Open("file.txt")
+       if err != nil {
+               log.Fatal(err)
+       }
+       defer f.Close()
+
+       h := md5.New()
+       if _, err := io.Copy(h, f); err != nil {
+               log.Fatal(err)
+       }
+
+       fmt.Printf("%x", h.Sum(nil))
+}

diff --git a/src/crypto/sha1/example_test.go b/src/crypto/sha1/example_test.go
index 42aec8afa26e3f6d989c99558160d78607cf442d..499055cc9627c83f76c5a0d1c994e10cc60f8624 100644 (file)
--- a/src/crypto/sha1/example_test.go
+++ b/src/crypto/sha1/example_test.go
@@ -8,6 +8,8 @@ import (
        "crypto/sha1"
        "fmt"
        "io"
+       "log"
+       "os"
 )
 
 func ExampleNew() {
@@ -23,3 +25,18 @@ func ExampleSum() {
        fmt.Printf("% x", sha1.Sum(data))
        // Output: af 06 49 23 bb f2 30 15 96 aa c4 c2 73 ba 32 17 8e bc 4a 96
 }
+
+func ExampleNew_file() {
+       f, err := os.Open("file.txt")
+       if err != nil {
+               log.Fatal(err)
+       }
+       defer f.Close()
+
+       h := sha1.New()
+       if _, err := io.Copy(h, f); err != nil {
+               log.Fatal(err)
+       }
+
+       fmt.Printf("% x", h.Sum(nil))
+}

diff --git a/src/crypto/sha256/example_test.go b/src/crypto/sha256/example_test.go
index 0eb70b711b8a17bac2fdc1c1b0d81a6520df5e91..7d73120155cab815bf542fefebb48e57b0300387 100644 (file)
--- a/src/crypto/sha256/example_test.go
+++ b/src/crypto/sha256/example_test.go
@@ -7,6 +7,9 @@ package sha256_test
 import (
        "crypto/sha256"
        "fmt"
+       "io"
+       "log"
+       "os"
 )
 
 func ExampleSum256() {
@@ -21,3 +24,18 @@ func ExampleNew() {
        fmt.Printf("%x", h.Sum(nil))
        // Output: a948904f2f0f479b8f8197694b30184b0d2ed1c1cd2a1ec0fb85d299a192a447
 }
+
+func ExampleNew_file() {
+       f, err := os.Open("file.txt")
+       if err != nil {
+               log.Fatal(err)
+       }
+       defer f.Close()
+
+       h := sha256.New()
+       if _, err := io.Copy(h, f); err != nil {
+               log.Fatal(err)
+       }
+
+       fmt.Printf("%x", h.Sum(nil))
+}