cs/main.go
2016-01-03 20:16:43 -08:00

59 lines
990 B
Go

package main
import (
"crypto/md5"
"crypto/sha1"
"crypto/sha256"
"crypto/sha512"
"flag"
"fmt"
"io"
"os"
)
var algo = flag.String("a", "sha1", "algorithm to use")
func main() {
flag.Parse()
files := flag.Args()
h := sha256.New()
switch *algo {
case "sha1", "1":
h = sha1.New()
case "sha256", "256":
h = sha256.New()
case "sha512", "512":
h = sha512.New()
case "md5":
h = md5.New()
default:
fmt.Fprintf(os.Stderr, "unsupported algorithm: %v\n", *algo)
os.Exit(1)
}
if len(files) == 0 {
_, err := io.Copy(h, os.Stdin)
if err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
os.Exit(1)
}
fmt.Printf("%x -\n", h.Sum(nil))
} else {
for _, name := range files {
f, err := os.Open(name)
if err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
continue
}
h.Reset()
_, err = io.Copy(h, f)
f.Close()
if err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
continue
}
fmt.Printf("%x %s\n", h.Sum(nil), name)
}
}
}