From perlop...

       As more readable alternatives to "&&" and "||" when used
       for control flow, Perl provides "and" and "or" operators
       (see below).  The short-circuit behavior is identical.
       The precedence of "and" and "or" is much lower, however,
       so that you can safely use them after a list operator
       without the need for parentheses:

           unlink "alpha", "beta", "gamma"
                   or gripe(), next LINE;

       With the C-style operators that would have been written
       like this:

           unlink("alpha", "beta", "gamma")
                   || (gripe(), next LINE);

       Using "or" for assignment is unlikely to do what you want;
       see below.
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Those who know that they are profound strive for clarity. Those who
would like to seem profound to the crowd strive for obscurity.
            --Friedrich Nietzsche

# and syntax
if (($i > 0) && ($i < 40)) {
    # do something
}

# or syntax
if (($i >0) || ($i < 40)) {
    # do something
}
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#have a cgi var default to something

#option 1
$x = $cgi->param("input_var") or "foo";
#option 2
$x = $cgi->param("input_var") || "foo";

#have open a file or die 

#option 1
open( HANDLE, "foo.txt" ) or die;
#option 2
open( HANDLE, "foo.txt" ) || die;

#have some sort of logic test
#option 1
if( $x eq "foo" or $y eq "bar" )
#option 2
if( $x eq "foo" || $y eq "bar" )
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