ugh.book

160 csh, pipes, and find

fact, even if it prints an error message to the screen, it still reports

“good news,” i.e., status 0. Try this in a shell script:

tar cf temp.tar no.such.file

if( $status == 0 ) echo "Good news! No error."

and you get this:

tar: no.such.file: No such file or directory

Good news! No error.

I know—I shouldn’t have expected anything consistent, useful, doc-

umented, speedy, or even functional...

Bjorn

Pipes ..........................................................................................

My judgment of Unix is my own. About six years ago (when I first got

my workstation), I spent lots of time learning Unix. I got to be fairly

good. Fortunately, most of that garbage has now faded from mem-

ory. However, since joining this discussion, a lot of Unix supporters

have sent me examples of stuff to “prove” how powerful Unix is.

These examples have certainly been enough to refresh my memory:

they all do something trivial or useless, and they all do so in a very

arcane manner.

One person who posted to the net said he had an “epiphany” from a

shell script (which used four commands and a script that looked like

line noise) which renamed all his '.pas' files so that they ended with

“.p” instead. I reserve my religious ecstasy for something more than

renaming files. And, indeed, that is my memory of Unix tools—you

spend all your time learning to do complex and peculiar things that

are, in the end, not really all that impressive. I decided I’d rather

learn to get some real work done.

—Jim Giles

Los Alamos National Laboratory

Unix lovers believe in the purity, virtue, and beauty of pipes. They extol

pipes as the mechanism that, more than any other feature, makes Unix

Unix. “Pipes,” Unix lovers intone over and over again, “allow complex