Re: [Bug-tar] Is there a drop-in replacement for tar that allows random read/write and concurrent access to different entries in the archive?

[Tim Kientzle]

> On Feb 19, 2017, at 1:31 PM, Peng Yu <address@hidden> wrote:
> 
> Does anybody know if there is a drop-in replacement of tar that can support 
> both features (random access and concurrency)?
> 

What do you mean "replacement of tar"?

1.  Do you mean "command line program with the same options but possibly a 
completely different format"?

2.  Or do you mean "possibly different implementation that uses the same 
format"?

The tar file format can handle random access if you're wiling to scan the 
archive and build an in-memory directory.  (Streaming compression such as gzip 
makes this much, much harder.)  It cannot handle concurrent writes, though.

There are many archiving formats that support random access -- Zip and Xar, for 
example.  There are standard libraries that you can use to build whatever CLI 
you want for it.  But again, I'm not familiar with any that can handle 
concurrent writes.

Concurrent write is a problem that archiving formats generally do not address 
-- you're basically talking about filesystems.  I believe there are library 
implementations of several filesystems that you could use for this.

Tim