Re^2: standard perl routine

If I understand the docs correctly, POSIX automatically exports pretty much everything except for subroutine names that conflict with Perl built-ins. If you wish to protect your namespace, the easiest way to override this unfortunate behavior is to invoke POSIX like this:

use POSIX (); # Import nothing.

print POSIX::pow( 2, 3 ); # Use the fully-qualified name.
[download]

Dave

Comment on Re^2: standard perl routine Download Code

Replies are listed 'Best First'.
Re^3: standard perl routine by BrowserUk (Patriarch) on Apr 30, 2006 at 08:01 UTC
Specifying an import list explicitly prevents POSIX from importing anything other than the functions you specify: `c:\test\546536>p1 print scalar keys %main::;; ## Before use POSIX main has how many glob +als? 67 use POSIX qw[ pow ];; print scalar keys %main::;; ## and after is has 72 Terminating on signal SIGINT(2) c:\test\546536>p1 $h{ $_ }++ for keys %main::;; ## Record what we have before use POSIX qw[ pow ];; $h{ $_ }++ for keys %main::;; ## Again after print for grep{ $h{ $_ } == 1 } keys %h;; ## Display the differences _<c:/Perl/lib/auto/POSIX/POSIX.dll XSLoader:: POSIX:: pow _<POSIX.c` [download] Two 'private' paths, two new namespaces and one new function (pow) in main. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re^4: standard perl routine by davido (Cardinal) on Apr 30, 2006 at 08:03 UTC
Ah, so it does. Good call. The same mechanism that makes `use POSIX ();` (ie, import an empty list) exclude all, also makes `use POSIX qw/pow/;` exclude all others. Dave	[reply] [d/l] [select]