vim commands in perl

JohanLingen · 01-07-2003, 05:16 PM

I'm trying to write a perl script which deletes usernames in a file. Since perl does not have the tools (or does it?) to delete lines directly in a file, I tried to open the file with an linux editor:

exec('ex /home/users/johanl/data/praatjes');

so far so good (exept for the small thing, I would like to use something like

exec('ex $file');

but that doesn't work.)

but now, whatever I do, every time I execute the script it stops at de ex prompt.

How do I give commands like "go to line $count" ($countG?) and "delete this line" (dd?)

your help would be appreciated

lackluster · 01-07-2003, 08:11 PM

first off, exec REPLACES your process, so control will not be returned to your script (unless there's a problem). second, just open your file in perl, name it xfile.newfile and write to that every line but the one you want to delete .... or look up the -i option (is that the edit-in-place one? I can never remember ...)

lackluster · 01-07-2003, 08:17 PM

also, you can pipe to a program using

Code:

open (PIPEY, "| emacs"); # I don't know vi(?:m)?
print PIPEY '#!/usr/bin/perl'."\n\n";
print PIPEY 'print "Just Another Perl Hacker\n";'."\n";
print PIPEY <ctrl-x><ctrl-f>; #don't know the values .. .sorry
print PIPEY "genfile.pl\n";
close PIPEY;
system("chmod +x genfile.pl");
exec("genfile.pl");
die ("Something wrong executing genfile.pl!\n$!\n");

THis code is untested, and most probably littered with a syntax error or so, but hopefully you get the idea.

moses · 01-07-2003, 09:10 PM

Perl is perfect for processing text files. Point your browser to the
Perl web page, and read up on it. You don't need to use an editor.
http://learn.perl.org

JohanLingen · 01-08-2003, 04:29 AM

lackluster:

I tried the -i option or -i.bak to make a backup also, but it doesn't work (or I don't use it in the right way

)

I will try pipe programming this afternoon, maybe that offers me a way out.

I thought about writing things to another file, but I want to settle this for all

Suppose I have a huge file, and I want to do the same thing: search for a line and delete it... then writing the file would cost the same huge amount of disk space.

and moses:
that's a beautiful site you gave me, but as far as I can see it only offers books for sale?

moses · 01-08-2003, 04:43 AM

This might help a little more:
http://www.perl.com/pub/q/documentation