SAMS Teach Yourself Perl in 24 Hours THIRD EDITION

Example: File Information Class

If you recall from last hour, you built a module to give information on files. After building the module, it had a series of defects. Each of those defects can easily be fixed by using a class instead of a regular module.

The object-oriented version of the file information module is presented in Listing 18.6.

Listing 18.6. The FileInfo Module, as a Class.

1: #!/usr/bin/perl -w 2: 3: package TYPFileInfoOO; 4: use strict; 5: 6: sub new { 7: my($class,$filename)=@_; 8: if (! -e $filename) { 9: die "$filename doesn't exist!"; 10: } 11: bless { filename => $filename }; 12: } 13: sub bytes { # Returns the size of the file in bytes 14: my($self)=@_; 15: return -s $self->{filename}; 16: } 17: sub lines { # Returns the ...