Go语言常见哈希函数的使用

myhash.go

/**
 * created with intellij idea.
 * user: liaojie
 * date: 12-9-8
 * time: 下午3:53
 * to change this template use file | settings | file templates.
 */
package main
import (
  "crypto/md5"
  "crypto/sha1"
  "crypto/sha256"
  "crypto/sha512"
  "flag" //命令行选项解析器
  "fmt"
  "hash"
  "io"
  "os"
)
var style = flag.string("s", "sha256", "采用的哈西函数:sha1,sha256")
var filename = flag.string("f", "", "需要计算散列值的文件名")
func main() {
  flag.parse()
  var hs hash.hash
  switch *style {
  case "md5":
    hs = md5.new()
  case "sha1":
    hs = sha1.new()
  case "sha512":
    hs = sha512.new()
  default:
    hs = sha256.new()
  }
  if len(*filename) == 0 {
    filein, err := os.open(flag.args()[len(flag.args())-1])
    if err != nil {
      return
    } else {
      io.copy(hs, filein)
    }
  } else {
    filein, err := os.open(*filename)
    if err != nil {
      return
    } else {
      io.copy(hs, filein)
    }
  }
  hashstring := hs.sum(nil)
  fmt.printf("%x\n", hashstring)
}

以上所述就是本文的全部内容了，希望大家能够喜欢。