From ece00da8dcd3e9b6976e59a6d0ee92eca6a5db2c Mon Sep 17 00:00:00 2001
From: dtluna <dtluna@waifu.club>
Date: Wed, 27 Mar 2019 14:19:19 +0300
Subject: [PATCH] Add sha1sum

---
 README.md          |  2 +-
 hashsum.go         | 19 ++++++++++++++-----
 sha1sum/sha1sum.go |  9 +++++++++
 3 files changed, 24 insertions(+), 6 deletions(-)
 create mode 100644 sha1sum/sha1sum.go

diff --git a/README.md b/README.md
index 4137675..a979d16 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,7 @@ Utilities:
  * [ ] `sed`
  * [ ] `seq`
  * [ ] `setsid`
- * [ ] `sha1sum`
+ * [x] `sha1sum`
  * [ ] `sha224sum`
  * [ ] `sha256sum`
  * [ ] `sha384sum`
diff --git a/hashsum.go b/hashsum.go
index 341c571..e15ecc2 100644
--- a/hashsum.go
+++ b/hashsum.go
@@ -3,6 +3,7 @@ package coreutils
 import (
 	"bufio"
 	"crypto/md5"
+	"crypto/sha1"
 	"errors"
 	"fmt"
 	"hash"
@@ -14,24 +15,32 @@ import (
 )
 
 var MD5Regex = regexp.MustCompile("^(?P<hash>[0-9a-f]{32})  (?P<filename>.*)$")
+var SHA1Regex = regexp.MustCompile("^(?P<hash>[0-9a-f]{40})  (?P<filename>.*)$")
 
-func MD5Sum(r io.Reader) (hash.Hash, error) {
-	h := md5.New()
+// SumFunc is a type of function that computes a hash.Hash for data in io.Reader
+type SumFunc func(io.Reader) (hash.Hash, error)
+
+func copyIntoHash(r io.Reader, h hash.Hash) (hash.Hash, error) {
 	if _, err := io.Copy(h, r); err != nil {
 		return nil, err
 	}
 	return h, nil
 }
 
+func MD5Sum(r io.Reader) (hash.Hash, error) {
+	return copyIntoHash(r, md5.New())
+}
+
+func SHA1Sum(r io.Reader) (hash.Hash, error) {
+	return copyIntoHash(r, sha1.New())
+}
+
 type CheckingResults struct {
 	ImproperlyFormattedCount uint
 	InvalidChecksumCount     uint
 	FilesNotRead             uint
 }
 
-// SumFunc is a type of function that computes a hash.Hash for data in io.Reader
-type SumFunc func(io.Reader) (hash.Hash, error)
-
 // ImproperlyFormattedErr is an error return when a line for checking
 // has an incorrect number or set of characters
 var ImproperlyFormattedErr = errors.New("improperly formatted line")
diff --git a/sha1sum/sha1sum.go b/sha1sum/sha1sum.go
new file mode 100644
index 0000000..d12d2c1
--- /dev/null
+++ b/sha1sum/sha1sum.go
@@ -0,0 +1,9 @@
+package main
+
+import (
+	common "source.heropunch.io/tomo/go-coreutils"
+)
+
+func main() {
+	common.SumMain(common.SHA1Regex, common.SHA1Sum)
+}