comm '! sort file1' '! sort file2'

[Jason Zions]

> / ado at elsie.UUCP (Arthur David Olson) /  8:20 am  Sep 22, 1986 /
> I regularly want to run "comm" on a pair of unsorted files.
> 	[ ... ]
> All fine and dandy.  But then I got to thinking. . .that what I'd *really*
> like to be able to do is use a command like
> 
> 	comm '! sort file1' '! sort file2'
> 
> (where the space after the '!' should be your clue that I use csh) and have
> comm do the dirty work.
> 
> And then I got to thinking. . .that if fopen turned
> 	fopen("!whatever", "r")
> calls into
> 	popen("whatever", "r")
> calls (with other changes as necessary), then what I'd like to see happen
> with the "comm" command would happen generally.

You can do this more easily. Create a program, bang.c, the name of whose
executable is  !  . All this sucker does is a mktemp, then executes the
rest of the command line as a command, redirecting stdout into the temporary
file. !'s output is just the name of the temporary file.

Admittedly, it's a bit dirty; the file isn't deleted, so /tmp could fill up
quick. Perhaps ! could fork; the child sleeps for 5 minutes, then unlinks
the temporary file. This depends on comm (or whatever) opening the temporary
file soon enough. You could make the 5 minutes into 1 hour and be pretty sure.

I would select some character other than ! as a command name; perhaps @. Not
sacred to any shell that I know of.

How's that?
--
This is not an official statement of Hewlett-Packard Corp., and does not 
necessarily reflect the views of HP. It is provided completely without warranty
of any kind. Lawyers take 3d10 damage and roll a saving throw vs. ego attack.

Jason Zions				Hewlett-Packard
Colorado Networks Division		3404 E. Harmony Road
Mail Stop 102				Ft. Collins, CO  80525
	{ihnp4,seismo,hplabs,gatech}!hpfcdc!hpcnoe!jason