egrep question

internal_war · 05-05-2005, 03:27 PM

A friend posed a question to me and I have been unable to figure it out, maybe some genius mind out there can help me. Here goes: (using egrep) Display the records in xxx.dat that contain 30 or more characters. Put them in a file called 'zzz' overwritting.

What I have so far is: grep "(...whatever)" xxx.dat > zzz

Tinkster · 05-05-2005, 03:39 PM

Looks like a home-work question to me ...

Please re-read the rules
http://www.linuxquestions.org/rules.php

Cheers,
Tink

internal_war · 05-05-2005, 04:28 PM

it isn't a homework question actually, I happen to have been out of college for about 7 years and I'm new to Linux (which I've installed about 4 months ago). My friend has been using Linux and Unix for a number of years and he tries to help me out by posing these sorts of questions. I resent the accusation that you think so though, I'm sure somebody will help me other than here.

Tinkster · 05-05-2005, 04:46 PM

Calm down mate, and give that animosity a miss.
Look at the type of question. That's something that
just doesn't happen in a real-life environment. The
fact that your pal is trying to get you to know Linux
better still makes it a "homework" question if you
look at it closely.

Do a "man egrep" and read the bit about
"REGULAR EXPRESSIONS"
(a quick way to get there is

Code:

man egrep
/REGULAR EXPRESSIONS<CR>

In particular, look at the bits that deal
with { } constructs.

Cheers,
Tink

internal_war · 05-05-2005, 04:50 PM

Ok I see what you're saying, sorry for half flipping on you, I've been trying to try to figure this out for about 4 days now.... it's just getting on my nerves.

Tinkster · 05-05-2005, 06:10 PM

No worries :)

Have you been able to locate the {} things and use them?
If NOT, the quick answer is:

egrep -e".{30,}" <filename> > <otherfilename>

You should try to read and understand that (using
the man-page), though.

Cheers,
Tink

internal_war · 05-05-2005, 06:32 PM

Quote:

Originally posted by Tinkster
egrep -e".{30,}" <filename> > <otherfilename>

ah i had the {30,} never thought about a . thanks.