Have you ever had to maintain someone else's code?
Have you ever had to maintain code like this?
my $variableThatContainsData = someSubroutineThatMucksWithData( $someAwfulVariable );
The mixed-case-for-words is called camelCase in the Perl world, and it's generally frowned upon because it makes reading code difficult.
Even with the horrible names, using underscores makes things more readable:
my $variable_that_contains_data = some_subroutine_that_mucks_with_data( $some_awful_variable );
For any program you expect to maintain, reuse, or distribute (that is, for any program), you should have the following lines of code:
#!/usr/bin/perl use strict; use warnings;
Although, if your Perl is older than 5.6, you need to do this instead:
#!/usr/bin/perl -w use strict;
strict makes Perl complain about uncertain coding constructs, such as undeclared variables, barewords, and "soft" references. These warnings will cause Perl to die.
#!/usr/bin/perl use strict; $foo = 4; # undeclared variable error $foo = Bar; # bareword error my $bat = "foo"; print $$bat; # reference error
warnings makes Perl complain even more verbosely, but unlike
strict, these complaints are not fatal under ordinary circumstances.
#!/usr/bin/perl use warnings; $a + 0; # void context warning # name used once warning # undef warning print "program continued\n"; # prints
If you want
warnings to be fatal, tell it so:
use warnings FATAL => 'all'; $a + 0; # void warning and then exits print "program continued\n"; # doesn't print
Submit a PR to github.com/petdance/perl101
© 2007-2018 Andy Lester