Re: disable functions if module not installed

Something like this works for me:

our $is_magick;
BEGIN {
  $is_magick = eval "require Image::Magick" ? 1 : 0;
}
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(my $is_magick; is fine, too, btw)

Note that the assignment in our $is_magick = 1; in your snippet would be executed after the BEGIN block... Also, the BEGIN block is only necessary if you need $is_magick's state to be valid early on.

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Re^2: disable functions if module not installed by Anonymous Monk on Nov 04, 2008 at 12:42 UTC
require returns true on success, and string-eval eats memory :) `BEGIN { $is_magick = eval {require Image::Magick;}; } C:\>perl -e"print require CGI;" 1 C:\>perl -e"print require CGIshamalamadingdong;" Can't locate CGIshamalamadingdong.pm in @INC` [download]	[reply] [d/l]
Re^3: disable functions if module not installed by almut (Canon) on Nov 04, 2008 at 13:59 UTC
require returns true on success, yes, and false (`undef`) otherwise. That was the idea :) string-eval eats memory Why would that be (in this case, where the string is just a few bytes)? Any tests/data to prove the claim? `C:\>perl -e"print require CGI;" 1 C:\>perl -e"print require CGIshamalamadingdong;" Can't locate CGIshamalamadingdong.pm in @INC` [download] Not sure what this is meant to demonstrate — I thought we were talking about `eval "require ..."`: `$ perl -E '$ok = eval "require CGI" ? 1:0; say $ok' 1 $ perl -E '$ok = eval "require CGIshamalamadingdong" ? 1:0; say $ok' 0` [download] (note: swap single and double quotes if you're on Windows)	[reply] [d/l] [select]