168 lines
5.1 KiB
Markdown
168 lines
5.1 KiB
Markdown
# tar-stream
|
|
|
|
tar-stream is a streaming tar parser and generator and nothing else. It is streams2 and operates purely using streams which means you can easily extract/parse tarballs without ever hitting the file system.
|
|
|
|
Note that you still need to gunzip your data if you have a `.tar.gz`. We recommend using [gunzip-maybe](https://github.com/mafintosh/gunzip-maybe) in conjunction with this.
|
|
|
|
```
|
|
npm install tar-stream
|
|
```
|
|
|
|
[](http://travis-ci.org/mafintosh/tar-stream)
|
|
[](http://opensource.org/licenses/MIT)
|
|
|
|
## Usage
|
|
|
|
tar-stream exposes two streams, [pack](https://github.com/mafintosh/tar-stream#packing) which creates tarballs and [extract](https://github.com/mafintosh/tar-stream#extracting) which extracts tarballs. To [modify an existing tarball](https://github.com/mafintosh/tar-stream#modifying-existing-tarballs) use both.
|
|
|
|
|
|
It implementes USTAR with additional support for pax extended headers. It should be compatible with all popular tar distributions out there (gnutar, bsdtar etc)
|
|
|
|
## Related
|
|
|
|
If you want to pack/unpack directories on the file system check out [tar-fs](https://github.com/mafintosh/tar-fs) which provides file system bindings to this module.
|
|
|
|
## Packing
|
|
|
|
To create a pack stream use `tar.pack()` and call `pack.entry(header, [callback])` to add tar entries.
|
|
|
|
``` js
|
|
var tar = require('tar-stream')
|
|
var pack = tar.pack() // pack is a streams2 stream
|
|
|
|
// add a file called my-test.txt with the content "Hello World!"
|
|
pack.entry({ name: 'my-test.txt' }, 'Hello World!')
|
|
|
|
// add a file called my-stream-test.txt from a stream
|
|
var entry = pack.entry({ name: 'my-stream-test.txt', size: 11 }, function(err) {
|
|
// the stream was added
|
|
// no more entries
|
|
pack.finalize()
|
|
})
|
|
|
|
entry.write('hello')
|
|
entry.write(' ')
|
|
entry.write('world')
|
|
entry.end()
|
|
|
|
// pipe the pack stream somewhere
|
|
pack.pipe(process.stdout)
|
|
```
|
|
|
|
## Extracting
|
|
|
|
To extract a stream use `tar.extract()` and listen for `extract.on('entry', (header, stream, next) )`
|
|
|
|
``` js
|
|
var extract = tar.extract()
|
|
|
|
extract.on('entry', function(header, stream, next) {
|
|
// header is the tar header
|
|
// stream is the content body (might be an empty stream)
|
|
// call next when you are done with this entry
|
|
|
|
stream.on('end', function() {
|
|
next() // ready for next entry
|
|
})
|
|
|
|
stream.resume() // just auto drain the stream
|
|
})
|
|
|
|
extract.on('finish', function() {
|
|
// all entries read
|
|
})
|
|
|
|
pack.pipe(extract)
|
|
```
|
|
|
|
The tar archive is streamed sequentially, meaning you **must** drain each entry's stream as you get them or else the main extract stream will receive backpressure and stop reading.
|
|
|
|
## Headers
|
|
|
|
The header object using in `entry` should contain the following properties.
|
|
Most of these values can be found by stat'ing a file.
|
|
|
|
``` js
|
|
{
|
|
name: 'path/to/this/entry.txt',
|
|
size: 1314, // entry size. defaults to 0
|
|
mode: 0644, // entry mode. defaults to to 0755 for dirs and 0644 otherwise
|
|
mtime: new Date(), // last modified date for entry. defaults to now.
|
|
type: 'file', // type of entry. defaults to file. can be:
|
|
// file | link | symlink | directory | block-device
|
|
// character-device | fifo | contiguous-file
|
|
linkname: 'path', // linked file name
|
|
uid: 0, // uid of entry owner. defaults to 0
|
|
gid: 0, // gid of entry owner. defaults to 0
|
|
uname: 'maf', // uname of entry owner. defaults to null
|
|
gname: 'staff', // gname of entry owner. defaults to null
|
|
devmajor: 0, // device major version. defaults to 0
|
|
devminor: 0 // device minor version. defaults to 0
|
|
}
|
|
```
|
|
|
|
## Modifying existing tarballs
|
|
|
|
Using tar-stream it is easy to rewrite paths / change modes etc in an existing tarball.
|
|
|
|
``` js
|
|
var extract = tar.extract()
|
|
var pack = tar.pack()
|
|
var path = require('path')
|
|
|
|
extract.on('entry', function(header, stream, callback) {
|
|
// let's prefix all names with 'tmp'
|
|
header.name = path.join('tmp', header.name)
|
|
// write the new entry to the pack stream
|
|
stream.pipe(pack.entry(header, callback))
|
|
})
|
|
|
|
extract.on('finish', function() {
|
|
// all entries done - lets finalize it
|
|
pack.finalize()
|
|
})
|
|
|
|
// pipe the old tarball to the extractor
|
|
oldTarballStream.pipe(extract)
|
|
|
|
// pipe the new tarball the another stream
|
|
pack.pipe(newTarballStream)
|
|
```
|
|
|
|
## Saving tarball to fs
|
|
|
|
|
|
``` js
|
|
var fs = require('fs')
|
|
var tar = require('tar-stream')
|
|
|
|
var pack = tar.pack() // pack is a streams2 stream
|
|
var path = 'YourTarBall.tar'
|
|
var yourTarball = fs.createWriteStream(path)
|
|
|
|
// add a file called YourFile.txt with the content "Hello World!"
|
|
pack.entry({name: 'YourFile.txt'}, 'Hello World!', function (err) {
|
|
if (err) throw err
|
|
pack.finalize()
|
|
})
|
|
|
|
// pipe the pack stream to your file
|
|
pack.pipe(yourTarball)
|
|
|
|
yourTarball.on('close', function () {
|
|
console.log(path + ' has been written')
|
|
fs.stat(path, function(err, stats) {
|
|
if (err) throw err
|
|
console.log(stats)
|
|
console.log('Got file info successfully!')
|
|
})
|
|
})
|
|
```
|
|
|
|
## Performance
|
|
|
|
[See tar-fs for a performance comparison with node-tar](https://github.com/mafintosh/tar-fs/blob/master/README.md#performance)
|
|
|
|
# License
|
|
|
|
MIT
|