go-examples/shadirconcurrent/main.go

65 lines
1.1 KiB
Go

package main
import "fmt"
import "crypto/sha256"
import "io"
import "log"
import "os"
import "path/filepath"
import "sync/atomic"
var chan_hash chan string
var running int32
func walk(path string, info os.FileInfo, err error) error {
if err != nil {
log.Fatalln(err)
return err
}
if info.IsDir() {
return nil
} else {
atomic.AddInt32(&running, 1)
go hash(info.Name(), path)
}
return nil
}
func hash(name string, path string) {
h, err := sha256File(path)
if err != nil {
log.Fatalln(err)
}
chan_hash <- fmt.Sprintf("SHA256 (%s) = %x", name, h)
}
func sha256File(path string) ([]byte, error) {
f, err := os.Open(path)
if err != nil {
log.Fatalln(err)
return nil, err
}
defer f.Close()
h := sha256.New()
io.Copy(h, f)
return h.Sum(nil), nil
}
func main() {
if len(os.Args) < 2 {
log.Fatalln("Usage shadir file")
}
chan_hash = make(chan string)
if err := filepath.Walk(os.Args[1], walk); err != nil {
panic(err)
}
for str := range chan_hash {
fmt.Println(str)
atomic.AddInt32(&running, -1)
if running <= 0 {
return
}
}
}