[grepmail-devel] -o and -O output flags

[David C. <da...@co...>]

Greetings grepmail developers!

Terry Brown described this nasty problem:

$ grepmail -R pattern mail/ > mail/output

In this case grepmail could possibly search the output file, appending results
to itself!

One way to get around this problem is:

$ grepmail -R pattern mail/ > /tmp/output
$ mv /tmp/output mail/

but that's annoying. What about explicitly setting the output file with -o?

$ grepmail -R -o /tmp/output pattern mail/ 

Here, -o has the following semantics:

-o Specify the output file, overwriting any existing file. (If this file
  appears on the input list of files, it is ignored.)
-O Specify the output file, appending to any existing file. (If this file
  appears on the input list of files, it is ignored.)

The downsides are:

1) it's an obscure situation that doesn't seem to justify a new flag (or two).
Can anyone think of another reason for -o?
2) -o and -O seem to be shouldering work that is better done by the shell.
(appending vs. overwriting, for example)
3) Fighting feature-itis is good.

I kinda feel like this is a problem we shouldn't have to deal with, unless
introducing -o solves other problems. Any thoughts?

David

_________________________________________________________________________
David Coppit - Graduate Student        da...@co...      
The University of Virginia             http://coppit.org/
    "Yes," said Piglet, "Rabbit has Brain." There was a long silence.
"I suppose," said Pooh, "that that's why he never understands anything."