mirror of
https://github.com/vbatts/tar-split.git
synced 2024-12-26 07:16:32 +00:00
old.go: no need to keep this sitting here
This commit is contained in:
parent
72c5103763
commit
cefcbc6fe3
1 changed files with 0 additions and 236 deletions
236
old.go
236
old.go
|
|
@ -1,236 +0,0 @@
|
|||
// +build ignore
|
||||
|
||||
package main
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"crypto"
|
||||
"encoding/json"
|
||||
"errors"
|
||||
"flag"
|
||||
"io"
|
||||
"log"
|
||||
"os"
|
||||
"strconv"
|
||||
)
|
||||
|
||||
func main() {
|
||||
flag.Parse()
|
||||
|
||||
tarInfos := []TarInfo{}
|
||||
for _, arg := range flag.Args() {
|
||||
func() {
|
||||
// Open the tar archive
|
||||
fh, err := os.Open(arg)
|
||||
if err != nil {
|
||||
log.Fatal(err)
|
||||
}
|
||||
defer fh.Close()
|
||||
|
||||
fi, err := fh.Stat()
|
||||
if err != nil {
|
||||
log.Fatal(err)
|
||||
}
|
||||
|
||||
ti := TarInfo{
|
||||
Name: arg,
|
||||
Size: fi.Size(),
|
||||
}
|
||||
|
||||
for {
|
||||
buf, err := readHeader(fh)
|
||||
if err != nil {
|
||||
if err == io.EOF {
|
||||
break
|
||||
}
|
||||
log.Fatal(err)
|
||||
}
|
||||
|
||||
if !verifyChecksum(buf) {
|
||||
log.Fatal(ErrHeader)
|
||||
}
|
||||
|
||||
s := slicer(buf)
|
||||
name := cString(s.next(100))
|
||||
s.next(8) // mode
|
||||
s.next(8) // uid
|
||||
s.next(8) // gid
|
||||
size, err := octal(s.next(12))
|
||||
if err != nil {
|
||||
log.Fatal(err)
|
||||
}
|
||||
e := Entry{
|
||||
Header: buf,
|
||||
Name: name,
|
||||
Size: size,
|
||||
}
|
||||
log.Printf("%#v", e)
|
||||
ti.Entries = append(ti.Entries, e)
|
||||
|
||||
// TODO(vbatts) some pax types need further reading, for their headers ...
|
||||
// XXX this where it is broken
|
||||
if _, err := fh.Seek(size, 1); err != nil {
|
||||
log.Fatal(err)
|
||||
}
|
||||
}
|
||||
|
||||
tarInfos = append(tarInfos, ti)
|
||||
}()
|
||||
}
|
||||
if *flOutputJson != "" {
|
||||
fh, err := os.Create(*flOutputJson)
|
||||
if err != nil {
|
||||
log.Fatal(err)
|
||||
}
|
||||
defer fh.Close()
|
||||
jsonBuf, err := json.Marshal(tarInfos)
|
||||
if err != nil {
|
||||
log.Fatal(err)
|
||||
}
|
||||
_, err = fh.Write(jsonBuf)
|
||||
if err != nil {
|
||||
log.Fatal(err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
const BlockSize = 512
|
||||
|
||||
var (
|
||||
zeroBlock = make([]byte, BlockSize)
|
||||
hdrBuff = make([]byte, BlockSize)
|
||||
ErrHeader = errors.New("archive/tar: invalid tar header")
|
||||
|
||||
flOutputJson = flag.String("o", "", "output json of the tar archives")
|
||||
)
|
||||
|
||||
// cString parses bytes as a NUL-terminated C-style string.
|
||||
// If a NUL byte is not found then the whole slice is returned as a string.
|
||||
//
|
||||
// copied from 'archive/tar/reader.go'
|
||||
func cString(b []byte) string {
|
||||
n := 0
|
||||
for n < len(b) && b[n] != 0 {
|
||||
n++
|
||||
}
|
||||
return string(b[0:n])
|
||||
}
|
||||
|
||||
// parse the octal value from the byte array
|
||||
//
|
||||
// copied from 'archive/tar/reader.go'
|
||||
func octal(b []byte) (int64, error) {
|
||||
// Check for binary format first.
|
||||
if len(b) > 0 && b[0]&0x80 != 0 {
|
||||
var x int64
|
||||
for i, c := range b {
|
||||
if i == 0 {
|
||||
c &= 0x7f // ignore signal bit in first byte
|
||||
}
|
||||
x = x<<8 | int64(c)
|
||||
}
|
||||
return x, nil
|
||||
}
|
||||
|
||||
// Because unused fields are filled with NULs, we need
|
||||
// to skip leading NULs. Fields may also be padded with
|
||||
// spaces or NULs.
|
||||
// So we remove leading and trailing NULs and spaces to
|
||||
// be sure.
|
||||
b = bytes.Trim(b, " \x00")
|
||||
|
||||
if len(b) == 0 {
|
||||
return 0, nil
|
||||
}
|
||||
x, err := strconv.ParseUint(cString(b), 8, 64)
|
||||
return int64(x), err
|
||||
}
|
||||
|
||||
// copied from 'archive/tar/reader.go'
|
||||
func verifyChecksum(header []byte) bool {
|
||||
given, err := octal(header[148:156])
|
||||
if err != nil {
|
||||
return false
|
||||
}
|
||||
unsigned, signed := checksum(header)
|
||||
return given == unsigned || given == signed
|
||||
}
|
||||
|
||||
// POSIX specifies a sum of the unsigned byte values, but the Sun tar uses signed byte values.
|
||||
// We compute and return both.
|
||||
//
|
||||
// copied from 'archive/tar/reader.go'
|
||||
func checksum(header []byte) (unsigned int64, signed int64) {
|
||||
for i := 0; i < len(header); i++ {
|
||||
if i == 148 {
|
||||
// The chksum field (header[148:156]) is special: it should be treated as space bytes.
|
||||
unsigned += ' ' * 8
|
||||
signed += ' ' * 8
|
||||
i += 7
|
||||
continue
|
||||
}
|
||||
unsigned += int64(header[i])
|
||||
signed += int64(int8(header[i]))
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// copied from 'archive/tar/reader.go'
|
||||
type slicer []byte
|
||||
|
||||
// copied from 'archive/tar/reader.go'
|
||||
func (sp *slicer) next(n int) (b []byte) {
|
||||
s := *sp
|
||||
b, *sp = s[0:n], s[n:]
|
||||
return
|
||||
}
|
||||
|
||||
// readHeader looks for the first header segement from the provided reader
|
||||
//
|
||||
// partially copied from 'archive/tar/reader.go'
|
||||
func readHeader(r io.Reader) ([]byte, error) {
|
||||
// prep our buffer
|
||||
buf := hdrBuff[:]
|
||||
copy(buf, zeroBlock)
|
||||
|
||||
if _, err := io.ReadFull(r, buf); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// Two blocks of zero bytes marks the end of the archive.
|
||||
if bytes.Equal(buf, zeroBlock[0:BlockSize]) {
|
||||
if _, err := io.ReadFull(r, buf); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if bytes.Equal(buf, zeroBlock[0:BlockSize]) {
|
||||
return nil, io.EOF
|
||||
}
|
||||
return nil, ErrHeader // zero block and then non-zero block
|
||||
}
|
||||
|
||||
return buf, nil
|
||||
}
|
||||
|
||||
type (
|
||||
// for a whole tar archive
|
||||
TarInfo struct {
|
||||
Name string
|
||||
Size int64
|
||||
Entries []Entry
|
||||
|
||||
// TODO(vbatts) would be nice to satisfy the Reader interface, so that this could be passed directly to tar.Reader
|
||||
}
|
||||
|
||||
// each file from the tar archive has it's header copied exactly,
|
||||
//and payload of it's file Checksummed if the file size is greater than 0
|
||||
Entry struct {
|
||||
Pos int64
|
||||
Name string
|
||||
Header []byte
|
||||
Size int64
|
||||
Checksum []byte
|
||||
Hash crypto.Hash
|
||||
|
||||
// TODO(vbatts) perhaps have info to find the file on disk, to provide an io.Reader
|
||||
}
|
||||
)
|
||||
Loading…
Reference in a new issue