QA

Q&A

Q1:	In the File::Find module, what are the colons ( :: ) in the variable names ? Like $File::Find::dir ?
A1:	Perl modules can create alternate areas for variable names, called namespaces , so that the module's global variable names and your global variable names don't get mixed up. So a global variable in the Cwd module would be known as $Cwd::x . Most of your global variables actually have the full name of $main::x for $x . But for now, that's not important.
Q2:	I have a Windows 95/98/NT machine, and the module I want to use is not available through ActiveState's PPM . How can I install it?
A2:	Unfortunately, most of CPAN's modules assume that you have a full Unix-like development environment to compile and install modules; this kind of environment is not easy to put together on a Windows machine. If you're very handy with a C compiler, you can download a development environment and build your own module, but doing so is not easy. Some modules are written entirely in Perl, and it may just be a matter of opening the distribution and putting the files in the correct places.
Q3:	I have an older Perl program with require instead of use . What's require?
A3:	The require statement is similar to use , and because Perl 4 did not have the use keyword, it used require . (Follow that?) The require statement causes the interpreter to find a library file and include it in your program ”similar to use . However, the key difference is that a require happens whenever the require statement is run (at runtime), whereas the use directive happens when your program is first loaded (at compile time).