Exercise Perl

1. Hello World:
   Run a "hello world" script, displaying your name stored in a variable.

2. Regular Expressions:
   Write a Perl script that distinguishes valid from non-valid email address read in form stdin (some example addresses).

3. Variables, Operators and Loops:
   Write a Perl script that calculates an integer division with an arbitrary number of digits. Arguments are the two integer values and the desired number of digits in the result.

4. File IO:
   Read the ASCII data file and calculate the sum, mean and variance for each line, for each column and for all values in the file.
   Try you script on the same data, but with a data file containing random white spaces.