On Wed, 9 Feb 2000, Matt Tilley wrote:
> OK, here goes. My problem stems from dealing with a file that contains
> lines. Some of the lines I want to keep, while I want to discard others
> (based on the value of the field of the first column). It seems that the
> nutshell book deals more with files than with variables (this could just be a
> stumbling block of mine)
>
> I am looking for groups of lines that belong together - for instance, whenever
> a line starts with "HCA" I want to save that line to a file and append the
> following lines as long as they begin with IX????? or IY????? (the "?" are
> place markers - I know that I will have a five digit number there). As soon
> as the next HCA comes along, I want to do the same thing again.
So long as no other lines begin with IX or IY followed by a digit, this is
simple (once you know how, of course!)
egrep "^HCA|^I[XY][0-9]" filename
Note that those are not ctrl-H or ctrl-I, but a carrat followed by the H
or I respectively, which indicates that what follows the carret is at the
beginning of the line.
Perl be damned! I know you'll probably get tons of messages about perl
ways to do this, but this is shorter and faster than most, if not all of
them... :) Assuming that you're using GNU egrep, which is extremely
likely (almost a certainty) if you're on a linux system (Ron Schwartz,
Learning Perl, ch 1, p12).
Derek Martin
President, He-Man Perl Haters Club
(o.k., not really)
--
"Quis custodiet ipsos custodes?" "Who watches the watchmen?"
-Juvenal, Satires, VI, 347
Derek D. Martin | Senior UNIX Systems/Network Administrator
Arris Interactive | A Nortel Company
[EMAIL PROTECTED] | [EMAIL PROTECTED]
-------------------------------------------------
**********************************************************
To unsubscribe from this list, send mail to
[EMAIL PROTECTED] with the following text in the
*body* (*not* the subject line) of the letter:
unsubscribe gnhlug
**********************************************************
