perl

Perl regex search/replace FAQ: How do I replace every TAB character in a file with a comma? (More generally, how do I search for a Perl regex pattern, and replace it with a different string?)

Perl regex search and replace

Replacing each TAB character in a file with a comma character can be accomplished several different ways with Perl. The key in any approach is to perform a Perl regex search and replace operation.

(Note: Please make a backup of your file(s) before continuing.)

Summary: How to use a Perl foreach loop to print every element in a Perl array.

To look at how to print every element in a Perl array using the foreach operator, the first thing we need is a sample array. Let's assume that you have an array that contains the name of baseball teams, like this:

@teams = ('cubs', 'reds', 'yankees', 'dodgers');

If you just want to print the array with the array members separated by blank spaces, you can just print the array like this:

Perl file and directory FAQ: I'm often asked a question like this: "How do I do fill_in_the_blank for each file in a directory?"

I'll leave the "fill in the blank" part up to you. I've seen the need to do many things to every file in a directory - print each file, change one line in every file, rename the file - whatever. The cool part is that it's very easy to accomplish these tasks with Perl.

Here's a snippet of Perl code that prints a listing of every file in the current directory:

Perl URL FAQ: What is the easiest way to download the contents of a URL with Perl?

The easiest way I know to download the contents of a URL (i.e., "http://...") using Perl is to use the libwww-perl library, LWP.pm.

Once you have that Perl module installed, the code to download a URL looks like this:

I've been working on a Perl module that makes sending email messages a breeze, but one problem I had is that the Perl module MIME::Lite has a nasty way of failing when something goes wrong. I could not "catch" it's errors with die or warn, so after a little research, I found out how to deal with this problem using eval. According to one text, using eval is the only mechanism Perl has for exception handling.

Here's what I was doing that didn't work: