Learning Perl Objects, References amp;amp; Modules [Electronic resources] نسخه متنی

4.9 Exercises

The answers for all exercises can be found in Section A.3.

4.9.1 Exercise 1 [5 min]

Without running it, can you see what's wrong with
this piece of a program? If you can't see the
problem after a minute or two, see whether trying to run it will give
you a hint of how to fix it.

my %passenger_1 = {
name => 'Ginger',
age => 22,
occupation => 'Movie Star',
real_age => 35,
hat => undef,
};
my %passenger_2 = {
name => 'Mary Ann',
age => 19,
hat => 'bonnet',
favorite_food => 'corn',
};
my @passengers = (\%passenger_1, \%passenger_2);

4.9.2 Exercise 2 [30 min]

The
Professor's data file (mentioned earlier in this
chapter) is available as coconet.dat in the files
you can download from the O'Reilly web site. There
may be comment lines (beginning with a pound sign); be sure to skip
them. (That is, your program should skip them. You might find a
helpful hint if you read them!)

Modify the code from the chapter so that each source
machine's portion of the output shows the total
number of bytes from that machine. List the source machines in order
from most to least data transferred. Within each group, list the
destination machines in order from most to least data transferred to
that target from the source machine.

The result should be that the machine that sent the most data will be
the first source machine in the list, and the first destination
should be the machine to which it sent the most data. The Professor
can use this printout to reconfigure the network for efficiency.