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.

Perl reference vs. direct access vs. return Benchmark

This is a little Perl Script where I try to test what way is faster,  I test a normal reference(alias) in a sub vs. the direct access vs. normal access to a variable in a sub and then return the result, here is my Benchmark code:

Our test result: