Using the Perl Debugger
One of the more useful tools when it comes to exploring a language is the debugger. This tool allows you to see real-world programs in action and examine what they are doing.
First you need a Perl script. Listing 1.1 shows a program that computes the average grade for a list of students.
Listing 1.1. ave.pl (Line numbers added)
1 use strict;
2 use warnings;
3
4 while (<DATA>)
5 {
6 if (/^#/)
7 {
8 next;
9 }
10 my @grades = split /[ \t]+/, $_;
11 my $name = shift @grades;
12 my $ave = ($grades[0] + $grades[1] + $grades[2]) / 3;
13 print "Student $name Average $ave\n";
14 }
15
16 __DATA__
17 # Student Grade Grade Grade
18 oualline 98 95 92
19 smith 75 84 99
20 jones 45 26 55
|
Spelling __DATA____DATA__ is spelled “<Underscore><Underscore>DATA<Underscore><Underscore>” ... |
Get Perl for C Programmers now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
