*****  Running PERL from the command line for quick experienments  ******
           
   syntax:  perl -e ' --- Perl statements enclosed in single quotes --- '

chaos:~$ perl -e '$radius=10; $area=3.14 * $radius**2; print "\nArea: $area\n";'

Area: 314

chaos:~$ perl -e '$r=<>; $area= 3.14 * $r**2; print "\nArea is $area\n";'
5
                          
Area is 78.5              ---------------------------------------------------
                          print "Please enter the radius of the circle: ";
                          $r = <>;
                          $area = 3.14159 * $r ** 2;
                          print  "\nCircle with radius $r has total area"
                                .  " $area units.";

                          Please enter the radius of the circle: 100
 
                          Circle with radius 100 has total area 31415.9 units.
                          ----------------------------------------------------

chaos:~$ perl -e 'print "\nYour name? "; $a = <>; print "\t\t\t Hello $a \n";'

Your name? Mortimur
                         Hello Mortimur

chaos:~$ perl -e 'print "\n\UHello World\n\n";'

HELLO WORLD

chaos:~$ perl -e 'print "\n\LHello World\n\n";'

hello world

chaos:~$ perl -e 'for ($i=1; $i<=5; $i++) { print "$i Hello World\n"; }'
1 Hello World
2 Hello World
3 Hello World
4 Hello World
5 Hello World

chaos:~$ perl -e ' @a=qw(I am the snow balls thrown awfully terribly fearfully
                                                                   inaccurate); 
                  foreach $word (@a) 
                  { 
                     print "$word\n"; 
                  } 
                  print "\n\n"; '
I
am
the
snow
balls
thrown
awfully
terribly
fearfully
inaccurate