[lug] Bletcherous pipe, FIXME!

Jeffrey Haemer jeffrey.haemer at gmail.com
Fri Apr 3 10:14:54 MDT 2009


 From what I can tell, every pipeline is executed in a subshell just like a
> ().  I could be wrong though.

Here's an illustration that's easy to build on:

     cd /tmp | cd /etc
     pwd    # but you've gone nowhere

Neither cd in the pipeline has an effect on your working directory, which
means there's a subshell at work.  Turns out there's one for each piece:
each segment is in its own subshell (though they each get much of the
parent's environment).

Some folks learn this stuff by carefully reading the 90-page bash manual,
but simple demos stick in my head better.

Jeffrey Haemer <jeffrey.haemer at gmail.com>
720-837-8908 [cell]
303-997-1219 [Google Voice]
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