Merge pull request #233 from fjl/rlpdump

cmd/rlpdump: new helper command
This commit is contained in:
Jeffrey Wilcke 2015-01-05 17:42:52 +01:00
commit 2cfbf76db8

128
cmd/rlpdump/main.go Normal file
View File

@ -0,0 +1,128 @@
package main
import (
"bufio"
"bytes"
"encoding/hex"
"flag"
"fmt"
"io"
"os"
"strings"
"github.com/ethereum/go-ethereum/rlp"
)
var (
hexMode = flag.String("hex", "", "dump given hex data")
noASCII = flag.Bool("noascii", false, "don't print ASCII strings readably")
)
func init() {
flag.Usage = func() {
fmt.Fprintln(os.Stderr, "Usage:", os.Args[0], "[-noascii] [-hex <data>] [filename]")
flag.PrintDefaults()
fmt.Fprintln(os.Stderr, `
Dumps RLP data from the given file in readable form.
If the filename is omitted, data is read from stdin.`)
}
}
func main() {
flag.Parse()
var r io.Reader
switch {
case *hexMode != "":
data, err := hex.DecodeString(*hexMode)
if err != nil {
die(err)
}
r = bytes.NewReader(data)
case flag.NArg() == 0:
r = os.Stdin
case flag.NArg() == 1:
fd, err := os.Open(flag.Arg(0))
if err != nil {
die(err)
}
defer fd.Close()
r = bufio.NewReader(fd)
default:
fmt.Fprintln(os.Stderr, "Error: too many arguments")
flag.Usage()
os.Exit(2)
}
s := rlp.NewStream(r)
for {
if err := dump(s, 0); err != nil {
if err != io.EOF {
die(err)
}
break
}
fmt.Println()
}
}
func dump(s *rlp.Stream, depth int) error {
kind, size, err := s.Kind()
if err != nil {
return err
}
switch kind {
case rlp.Byte, rlp.String:
str, err := s.Bytes()
if err != nil {
return err
}
if len(str) == 0 || !*noASCII && isASCII(str) {
fmt.Printf("%s%q", ws(depth), str)
} else {
fmt.Printf("%s%x", ws(depth), str)
}
case rlp.List:
s.List()
defer s.ListEnd()
if size == 0 {
fmt.Printf(ws(depth) + "[]")
return nil
} else {
fmt.Println(ws(depth) + "[")
for i := 0; ; i++ {
if i > 0 {
fmt.Print(",\n")
}
if err := dump(s, depth+1); err == rlp.EOL {
break
} else if err != nil {
return err
}
}
fmt.Print(ws(depth) + "]")
}
}
return nil
}
func isASCII(b []byte) bool {
for _, c := range b {
if c < 32 || c > 126 {
return false
}
}
return true
}
func ws(n int) string {
return strings.Repeat(" ", n)
}
func die(args ...interface{}) {
fmt.Fprintln(os.Stderr, args...)
os.Exit(1)
}