[Bug-tar] Allow tar to use command for compressing consisiting of multiple words.

[Pavel Raiskup]

Hi all,

   I'm just trying to look at the bug here:

     https://bugzilla.redhat.com/819187

   In short, there would be nice to allow maintainers to specify something
   like this:

     ./configure --with-lzma="xz --format=lzma"

   This is somehow related to --use-compress-program and this thread:

     http://lists.gnu.org/archive/html/bug-tar/2012-08/msg00001.html

-----------

I started to thinking about this and there is not very easy solution.
This is probably why nobody hacked this in.

The problem imo is, how much we should be pedantic.  How far you want this
feature to be clever to be accepted into tar?   (thinking about the
escaping problem, when user wants to specify some whitespace inside
argument, e.g.).

There would be three basic solutions, (1) use strtok(str, " "), not
allowing user to pass whitespace into command argument, (2) use some kind
of escaping (little bit more hard for implementation) or (3) allow user to
pass ', ", \ characters usable for this.  Or?  Is there something user
could miss here?

Simple speaking, we need some function like:

  char ** string_to_argv(const char *str);
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I was unable to find existing solution in gnulib, is there something like
that?

Any suggestions?

Paul, do you think some function like this would be nice to hack into
gnulib?

Thanks,
Pavel