Read perldoc perlop (or perlop), specifically the section about qq. It is the "double quote" operator, that is, it allows you to specify the delimiters for a double-quoted string.

Often, it also helps to let Perl tell you how it sees some code:

perl -MO=Deparse -e " $key=substr ($input,0, index($input,qq/ /,-1));"
[download]

gives me

C:\>perl -MO=Deparse -e " $key=substr ($input,0, index($input,qq/ /,-1
+));"
$key = substr($input, 0, index($input, ' ', -1));
-e syntax OK
[download]

The qq/ / is seen by Perl as a simple string, just that it was delimited by slashes.

As others have already pointed out qq() is basically the same as double quotes. But I wonder about that code you have there. The -1 argument to to index is ignored, so basically what that line is doing is: IF $input contains at least one space, then $key is set to the beginning of $input up to (but excluding) the first space. If, on the other hand, $input contains no spaces, then $key is set to $input minus its last character (or the empty string, if $input is empty); this is because in this case index returns -1, and therefore substr removes the last character.

It looks like pretty nutty code to me.

Thank you all :) I really appreciated all the answers you provided :)

This Index should contain pointers to all the available things you wil
+l find or expect in Perl 5 such as:

    * built in variables
    * function names
    * operators
    * flow control structures
    * special characters of regular expressions
    * exported functions of standard modules
    * names of functions in other languages with the corresponding nam
+es in Perl.....
[download]