topic Re: Perl Help in Operating System - Linux

Perl Help

Shaf_1 — Mon, 20 Dec 2004 23:25:29 GMT

Hello,

I am trying to delete the first 15 lines from each text file I have. Is there a easy perl script for this?

The attached file is similar to the text file I am working with. It is always going to be the first 15 lines.

Re: Perl Help

Ermin Borovac — Tue, 21 Dec 2004 00:00:11 GMT

You can try the following

perl -ni.orig -e 'print if $. > 15' ...

It should delete first 15 lines in and leave original in .orig.

Re: Perl Help

Shaf_1 — Tue, 21 Dec 2004 00:14:56 GMT

Hello Ermin,

I tried this since I am trying to run it for over 1000 files at once. But what is happening is that it only update the first file.

perl -i -n -e 'print if$. > 15;' *.txt

What could I be doing wrong?

Re: Perl Help

Ermin Borovac — Tue, 21 Dec 2004 00:22:49 GMT

Just do it in a loop instead

for file in *.txt
do
perl -ni.orig -e 'print if $. > 15' $file
done

Re: Perl Help

Alexander Chuzhoy — Tue, 21 Dec 2004 03:23:34 GMT

Here's the desired perl script:
foreach $file (glob "*.txt") {
@ARGV=$file;
$^I=".bak";#creates backup with .bak extension
while (<>) {
if ($.>15) {
print;
}
}
}

By the way for any perl question refer to:
www.perlmonks.org
Best and quick answers.

Re: Perl Help

Vitaly Karasik_1 — Tue, 21 Dec 2004 04:43:33 GMT

"PERL oneliners" provides me with answers to 90% of my PERL needs:

http://www-106.ibm.com/developerworks/linux/library/l-p102.html

http://www.unixguide.net/unix/perl_oneliners.shtml

Re: Perl Help

Shaf_1 — Tue, 21 Dec 2004 15:28:58 GMT

This one liner works for one file at a time.

# delete first 10 lines
Â Â perl -i.old -ne 'print unless 1 .. 10' foo.txt

Is there a easy way to run it for a bunch of files at once?

Does it matter what shell I am

Re: Perl Help

Hein van den Heuvel — Tue, 21 Dec 2004 19:59:10 GMT

Just replace your filespec with a wild-carded on like *.txt

See for example:

http://www.rice.edu/web/perl-edit.html

The only tricky part with that iss to recognize file transitions, where you'll need to reset the line number for the work you want to do.

So a solution might be:

perl -ni.old -e 'print unless ($.<10); close ARGV if eof' *.txt

Hein.

Re: Perl Help

NiCK_76 — Thu, 23 Dec 2004 10:01:34 GMT

sed '1,15d' textfile

Re: Perl Help

Shaf_1 — Sun, 09 Jan 2005 17:49:12 GMT

Thanks for all the help.