Re: Leak in BASH "named" file descriptors?

[Chet Ramey]

On 4/13/16 9:34 AM, Pierre Gaston wrote:

> For me the value is in 1) not hard coding the number and 2) being able to
> use more explicit names (eg "logfile" rather than "3"), nothing more.

If you limit the effects to those two, it's not a compelling feature to
add.  In practice, the first is not a big problem if you're careful, and
the second can be trivially emulated with a single assignment statement.

> Of course if you use {var} for the redirections of an external command it's
> useless but not using a hard coded number can be useful if you use
> functions and don't want to have conflicts with someone else's function.

This is true, though bash does save and restore file descriptors where it
can if your hard-coded number is already in use.


> I don't really understand why using a symbolic name would need to provide
> more control, and in my opinion  {var}> doesn't really provide something
> you can't do otherwise regarding the handling of the fd, it just has a
> different behavior.

It's an opportunity to provide more flexible behavior.  The standard ways
to use file descriptors still exist, so if you don't like the different
behavior you have options.


-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/