UNIX for Dummies Questions & Answers

How can I extract few lines(like 10 to 15, top 10 and last 10) from a file using perl.

I do it with sed, head and tail in unix scripting. I am new to perl. Appreciate your help.

Hi, so far as I know, there isn't any truly easy way to do this in Perl in quite the same way that awk and sed provides.

But there are two Perl apps that will convert awk and sed code into Perl for you, so you can perhaps learn from them instead.

The first being a2p (awk to perl) and the second being s2p (sed to perl)

To answer one of your example questions, you can emulate "head" in sed with the command:

Code:

sed 10q

So, to convert that into Perl code and save it to a file for reading. The command:

Code:

s2p 10q > head.pl

Would acheive that.

Although, I did say that there isn't any truly easy way in Perl, and you may be quite blown by the output of that command.

Regards
Iain

There is an easy way out with perl too...

perl -ne 'print if $. >= 10; exit if $. >= 15;' filename1

Here $. is a special variable that represents current line number.

Regards,
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