Perl Regex named capture variables

Simple example to extract, protocol, server and domain from a given URL:

Our Result:

Perl find all pow 2 numbers

This little script finds all pow 2 numbers in Perl :

Our Result:

Perl print String difference

This function prints the difference between two strings with Perl:

You need the Module Term::ANSIColor, to highlight the changes,use it like this:

And the Result is :

ColorStringDiff

Perl check if file handler is open

If you write a function in Perl and want to check if the file handler is already open you could use this function:

It returns 0 if its undefined,closed or not open, an 1 if the handler is open.

 

In this little example I open a file to read and another to write, I check the sub before and after the open function, and before and after the close function.

The Result, looks like expected:

Perl print __DATA__ multiple times

Sometimes you have a lot of Data in Perl and you want to store in your script, for that you could you the __DATA__ token, you could simple read it with a file handle:

If you use it more than one time you should seek for the start position:

Output looks like this:

Perl read/write File

This is a simple example how to write into a File with Perl, and then read from it.At first we write the numbers from 1 to 6 into the file, in the second we read from the file and print it on the screen, if you don’t want the “\n” at the end use the function chomp.

If you open a File for read use ‘<‘, for write ‘>’ and for append ‘>>’.

Result looks like:

you could check if a handler is open with this Perl handler function.

Perl find lowest divisible number

This Perl Script find the lowest, divisible number from 1 to 10:

The result is 2520.

Fraction calculation in Perl

This Perl script is able to add,subtract,divide and multiply fractional numbers:

This is the output from 1/2 and 1.25, at first add both then subtract from the result, multiply and then divide from the result:

For a better result take a look at Perl high precision.

JavaScript generate an result array from XPATH

This is a function in JavaScript that use an XPATH string to generate an Array from the results.This is very useful if you have to manipulate or use some items on a page and don’t have the id(like bots).

That is the function:

You could use it in the Terminal:

And we get all hrefs on this page in the Terminal:

Use it to store it in an Array and then write it on the page:

and we got this result: