You provoked already two more effort shown, more help (possibly) get in return golden principle.. I suggest a first steps suggetion: describe your solution in english then translate it in Perl:

I want a program that advice me if I'm doing something wrong (hint: use strict; and use warnings also use diagnostic for first program is good).

My program must open a file in read mode. foreach line of this file (see loops at perlintro) I must remove the trailing newline aka chomp it.

Then I want the program to split the current line at every : and I want to append ( . is used to concatenate strings) the third field (but be aware array indexes strart from 0) to the hash value hold by the first field's key of a results hash. See again perlintro for hashes.

When the reading loop is termineted the hash is full of your wanted results.

I want to open a file in writing mode and looping the hash I write each one of the keys and value to that file.

L*