Perl: What exactly is C<our>?

Question

I am in the process of teaching my self Perl. I am using the EPIC debugger in Eclipse. Whenever I have a var used only one time in a sub I get this warning:
Typographical errors often show up as unique variable names. If you had a good reason for having a unique name, then just mention it again somehow to suppress the message. The C<our> declaration is provided for this purpose.
What is C<our>? Standard searching was inconclusive.

Answer 1

• As far as C<> part that may have confused you, it looks like EPIC took a text in POD format and printed it raw instead of rendering it from POD into a formatted text.

  C<our> in POD syntax means "Print text 'our' formatted as code", usually meaning mono-spaced font. This is similar to StackOverflow's `our` backtick-surrounded format command your own question used.

• The error itself comes from Perl's diagnostics module, which provides extended explanations for otherwise somewhat cryptic Perl warnings (in this case, "Name "%s::%s" used only once: possible typo"). As a matter of fact, judging from the POD formatting which confused you, EPIC probably uses the source POD from which the above-linked "perldiag" document was generated.

• If you're asking what our does, you should read perldoc -f our - it is a way to create an alias into a global variable effective in a given scope (see tchrist's asnwer for details).

• As far as googling technique in this case, when you're searching specifically for what you expect to be Perl keywords, it always pays to google for "perldoc someKeyword".

Answer 2

our is a lexically scoped alias to a global variable.