8.4 Input and the Default Variable

It is quite acceptable and extremely common to use the Perl default variable ($_) when reading input. This is ideal for the purposes of coding efficiency which, after all, is one of the corner stones of Perl. The following script, for example, will loop continuously reading user input and displaying the default variable until the EOF control character is entered by the user:

#!/usr/bin/perl

while (<STDIN>) {
       print "You entered $_";
}