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add check mode

pull/2/head
Stephen McQuay 4 years ago
parent
commit
f82decc6dc
No known key found for this signature in database GPG Key ID: 1ABF428F71BAFC3D
2 changed files with 121 additions and 2 deletions
  1. +103
    -0
      check.go
  2. +18
    -2
      main.go

+ 103
- 0
check.go View File

@ -0,0 +1,103 @@
package main
import (
"bufio"
"crypto/md5"
"crypto/sha1"
"crypto/sha256"
"crypto/sha512"
"errors"
"fmt"
"hash"
"io"
"log"
"os"
"strings"
)
type checksum struct {
filename string
hash hash.Hash
checksum string
}
func parseCS(line string) (checksum, error) {
elems := strings.Fields(line)
if len(elems) != 2 {
return checksum{}, fmt.Errorf("unexpected content: %d != 2", len(elems))
}
cs, f := elems[0], elems[1]
var hsh hash.Hash
switch len(cs) {
case 32:
hsh = md5.New()
case 40:
hsh = sha1.New()
case 64:
hsh = sha256.New()
case 128:
hsh = sha512.New()
default:
return checksum{}, fmt.Errorf("unknown format: %q", line)
}
return checksum{filename: f, hash: hsh, checksum: cs}, nil
}
func check(files []string) error {
streams := []io.ReadCloser{}
defer func() {
for _, stream := range streams {
stream.Close()
}
}()
for _, name := range files {
f, err := os.Open(name)
if err != nil {
return err
}
streams = append(streams, f)
}
if len(files) == 0 {
streams = append(streams, os.Stdin)
}
jobs := []checksum{}
for _, stream := range streams {
s := bufio.NewScanner(stream)
for s.Scan() {
cs, err := parseCS(s.Text())
if err != nil {
return err
}
jobs = append(jobs, cs)
}
if s.Err() != nil {
return s.Err()
}
}
errs := 0
for _, job := range jobs {
f, err := os.Open(job.filename)
if err != nil {
return fmt.Errorf("open: %v", err)
}
if _, err := io.Copy(job.hash, f); err != nil {
log.Printf("%+v", err)
}
f.Close()
if fmt.Sprintf("%x", job.hash.Sum(nil)) == job.checksum {
fmt.Printf("%s: OK\n", job.filename)
} else {
errs++
fmt.Fprintf(os.Stderr, "%s: bad\n", job.filename)
}
}
var err error
if errs != 0 {
err = errors.New("bad files found")
}
return err
}

+ 18
- 2
main.go View File

@ -12,10 +12,26 @@ import (
)
var algo = flag.String("a", "sha1", "algorithm to use")
var mode = flag.Bool("c", false, "check")
func main() {
flag.Parse()
files := flag.Args()
switch *mode {
case true:
if err := check(files); err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
os.Exit(1)
}
case false:
if err := hsh(files); err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
os.Exit(1)
}
}
}
func hsh(files []string) error {
h := sha256.New()
switch *algo {
case "sha1", "1":
@ -27,8 +43,7 @@ func main() {
case "md5":
h = md5.New()
default:
fmt.Fprintf(os.Stderr, "unsupported algorithm: %v\n", *algo)
os.Exit(1)
return fmt.Errorf("unsupported algorithm: %v", *algo)
}
if len(files) == 0 {
@ -55,4 +70,5 @@ func main() {
fmt.Printf("%x %s\n", h.Sum(nil), name)
}
}
return nil
}

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