Re^3: exit this way

Hi, Your Mother. Can you please explain this snippet? It does print out the randomly assigned value of $success if I change it to:

exit ! main();
sub main { $success = [ undef, "true" ]->[rand 2]; print "$success\n" 
+}
[download]

But it appears to produce the same output when I omit the !:

exit main();
sub main { $success = [ undef, "true" ]->[rand 2]; print "$success\n" 
+}
[download]

Which appears to be the same code as The Vague One posted ...

What is the function of the bang?

The way forward always starts with a minimal test.

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Re^4: exit this way by Your Mother (Archbishop) on Sep 01, 2015 at 15:45 UTC
:P The last expression of a sub/block/package is its return value; when there is no explicit `return`. So that little snippet just rotates returning "true" and "false" randomly; idiom: return 0 or 1 element of anon array with 2 elements, one true, one false. By adding a `print` you made the sub always return "true." `exit` values are approximately opposed to return/success values in most Perl. The bang (!) performs this inversion. `exit == 0` means success, any other value (-1, 1 .. 255) means some flavor of fail (on *nix anyway). Why I suggest it is cognitively a bad idea for a Perl script. To test the original, try these instead (with 1140673.pl being the first scriptlet I posted)- `moo@cow~>1140673.pl && echo "I CAN HAZ SUCCEED?" moo@cow~>1140673.pl \|\| echo "FAIL!"` [download]	[reply] [d/l] [select]
Re^5: exit this way by 1nickt (Canon) on Sep 01, 2015 at 16:16 UTC
OK, I see. Ugh, the Vague One obfuscated my thoughts ... I was focusing on whether the sub would be executed when called as the argument to `exit()`, rather than what that would make the output of the script via `exit()`. Thanks. The way forward always starts with a minimal test.	[reply] [d/l] [select]