Deleting lines with certain letters/keywords.

[bigb89]

Hi Guys,

I've tried google, but I could not find any answer. Here's what I need to do:

If I have a file that contains the letter a on certain lines, for example:

53a1
54b2
54o7
56a2

How could I delete the lines the have the letter a on it so the new file would loo like this:

54b2
54o7

P.S. I don't really mind the programming language to use to perform the above (perl, sed, tr, etc).

Regards,
--Bigb89