Browse Source

Add LICENSE and README.md. Set default concurrency to the number of

CPUs, and read stdin if no input files are specified.
master
Greg 2 years ago
parent
commit
e52426e80f
  1. 21
      LICENSE
  2. 24
      README.md
  3. 67
      main.go

21
LICENSE

@ -0,0 +1,21 @@
The MIT License (MIT)
Copyright (c) 2020 Gregory Pomerantz
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

24
README.md

@ -0,0 +1,24 @@
# b3sum
A golang port of b3sum
This is a simple `b3sum` command using `github.com/zeebo/blake3`.
```
go get git.wow.st/gmp/b3sum
go install git.wow.st/gmp/b3sum
```
## Usage:
```
b3sum [flags] [file]...
-h Prints help information
-l int
The number of output bytes, prior to hex encoding (default 32)
-p int
The maximum concurrency (defaults to the number of CPUs)
```
If no input files are specified, `b3sum` reads `stdin`.

67
main.go

@ -6,6 +6,7 @@ import (
"fmt"
"io"
"os"
"runtime"
"sync"
"github.com/zeebo/blake3"
@ -14,45 +15,53 @@ import (
var (
help = flag.Bool("h", false, "Prints help information")
length = flag.Int("l", 32, "The number of output bytes, prior to hex encoding")
par = flag.Int("p", 4, "The maximum concurrency")
par = flag.Int("p", runtime.NumCPU(), "The maximum concurrency")
)
func main() {
flag.Parse()
if *help || len(flag.Args()) == 0 || *par < 1 {
if *help || *par < 1 {
flag.Usage()
os.Exit(0)
}
q := make(chan struct{}, *par)
wg := &sync.WaitGroup{}
for _, name := range flag.Args() {
q <- struct{}{}
wg.Add(1)
go func(name string) {
buf := [65536]byte{}
file, err := os.Open(name)
if err != nil {
sum := func(file io.ReadCloser) string {
buf := [65536]byte{}
hasher := blake3.NewSized(*length)
for {
n, err := file.Read(buf[:])
hasher.Write(buf[:n])
if err == io.EOF {
break
} else if err != nil {
panic(err)
}
hasher := blake3.NewSized(*length)
for {
n, err := file.Read(buf[:])
hasher.Write(buf[:n])
if err == io.EOF {
break
} else if err != nil {
}
file.Close()
hash := hasher.Sum([]byte{})
return hex.EncodeToString(hash)
}
if len(flag.Args()) == 0 {
fmt.Println(sum(os.Stdin))
} else {
q := make(chan struct{}, *par)
wg := &sync.WaitGroup{}
for _, name := range flag.Args() {
q <- struct{}{}
wg.Add(1)
go func(name string) {
file, err := os.Open(name)
if err != nil {
panic(err)
}
}
file.Close()
hash := hasher.Sum([]byte{})
fmt.Print(hex.EncodeToString(hash))
fmt.Print(" ")
fmt.Println(name)
<- q
wg.Done()
}(name)
fmt.Print(sum(file))
fmt.Print(" ")
fmt.Println(name)
<- q
wg.Done()
}(name)
}
wg.Wait()
}
wg.Wait()
}
Loading…
Cancel
Save