go-examples/shadirconcurrent/main.go
2017-07-08 16:50:08 +02:00

62 lines
1.0 KiB
Go

package main
import "fmt"
import "crypto/sha256"
import "io"
import "log"
import "os"
import "path/filepath"
import "sync"
func sha256File(path string) (string, error) {
f, err := os.Open(path)
if err != nil {
return "", err
}
defer f.Close()
h := sha256.New()
io.Copy(h, f)
return fmt.Sprintf("SHA256 (%s) = %x", path, h.Sum(nil)), nil
}
func main() {
if len(os.Args) < 2 {
log.Fatalln("Usage shadir file")
}
var wg sync.WaitGroup
chan_hash, chan_path := make(chan string), make(chan string)
for i := 0; i < 100; i++ {
go func() {
for path := range chan_path {
if h, err := sha256File(path); err != nil {
wg.Done()
log.Print("Error "+path, err)
} else {
chan_hash <- h
}
}
}()
}
go func() {
for h := range chan_hash {
fmt.Println(h)
wg.Done()
}
}()
err := filepath.Walk(os.Args[1], func(path string, info os.FileInfo, err error) error {
if err == nil && !info.IsDir() {
wg.Add(1)
chan_path <- path
}
return err
})
if err != nil {
log.Fatalln(err)
}
wg.Wait()
}