On Thu, Jan 22, 2009 at 18:35, Owen <rc...@pcug.org.au> wrote: >> Hi Chas, >> >> Can you give me an example when one would be used over the other? So, >> is >> require used more for efficiency, so we load the module only if we >> need it? >> Thanks, >> -Ben > > > Bit of a conundrum there, if you don't need a module, why include it > in your program. snip
Happens quite often to me. If I am running on a UNIX machine, I don't need several Win32:: modules, and I don't want to even try to load them, but keeping two versions of the script (one for Win32 and one for UNIX-like machines) is too much trouble. See also the Factory pattern in my previous email. snip > Anyway you might have your own local subroutines to suit your > environment and procedures and may or may not be used by your main > programs . Place them in a perl program and register the program with > a 'require' statement. snip That is the old, bad way of doing things. Don't do it. Build a module and use use; it isn't hard. The require function should only be used when it is necessary to load modules at runtime. snip > If you get real keen, you can make a private module out of your local > subroutines. > > I have a general purpose perl program where I lump all my odd > requirements, the main one being 'trim' (a la php) for stripping > leading and trailing spaces and some odd date formatting for my own > use. snip This is the sort of thing I hate to see when I show up at a job. Someone has a pet file with all of their little odds and ends. And trim is one of the most useless functions you could write. What is so hard about $string =~ s/^[ ]*(.*)[ ]*$/$1/; True, it takes more characters, but I know exactly what is meant by it. If it is someones pet version of trim I have to go hunting for it to find out if they are trimming on the right, left, or both; does it work on whitespace, spaces, tabs, newlines, or some combination; does it modify in place, return a copy, or both; etc. Now, if you absolutely have to a trim function, don't reinvent the wheel, there are perfectly good modules on CPAN such as Text::Trim and String::Strip that are tested and documented. Remember, you are not just writing code for yourself, you are writing it for the sociopathic axe-murder who will work on it after you. -- Chas. Owens wonkden.net The most important skill a programmer can have is the ability to read. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
