Edit Flat file with perl

spragueg posted this at 13:13 — 9th September 2002.

Joined: Jan 2001

I have a flat file(tabbed text) that I'm able to pull data from an split into values and display in a browser using perl.

What I need to do now id be able to modify a line in the flat file. Each entry has a unique id number. How would I go about setting this up.

I can handle getting the data for the record to be edited and into a form. But beyond that I'm lost.

Does it involve pulling all the data from the file changing it and then writing is all back? Could some one provide a little sample code of how to do this just to get me started.

Thanks,
spragueg

Thanks
G

Wil posted this at 13:16 — 9th September 2002.

They have: 601 posts

Joined: Nov 2001

Yes, I can guide you and provide sample code, but firstly, can you supply us with sample data? Can you give me a snapshop of the file? And also, what part of the file (which column) would you like to modify?

- wil

ROB posted this at 15:21 — 9th September 2002.

They have: 447 posts

Joined: Oct 1999

quick sample

	open(MYFILE, 'path/to/myfile') || die();
	my @lines = <MYFILE>;
	close(MYFILE);

	open(MYFILE, '>path/to/myfile') || die();
	foreach(@lines) {
		chomp;

		# split the line into column data
		my ($id, $fname, $lname, $moredata) = split(/\t/);

		if($id == $idYouWantToChange) {
			# do stuff with the line here
		}

		# write the line back to file
		print MYFILE "$id\t$fname\t$lname\t$moredata\n";
	}
	
	close MYFILE;

spragueg posted this at 05:29 — 17th September 2002.

They have: 23 posts

Joined: Jan 2001

Ok That's what I thought however I am troubled by the writing it back part. Wouldn't MYFILE contain the original file contents. but you're showing only writing back the one line. Wouldn't I have to replace the current file in @lines with the new data and then put the @lines back into MYFILE? Then write the file?

Thanks
G

spragueg posted this at 05:46 — 17th September 2002.

They have: 23 posts

Joined: Jan 2001

Nevermind, I didn't get it when I first responded. I see the chomp; thing now. I like it. Exactly what I'm looking for!

Thanks much,
Graham