Re^2: Perl Module Object - Return fail/success with a fault string

Kinda? but not really, the below doesn't seem to work

print "Sub failed with error: $rv" if (!$rv);
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Meaning that it doesn't actually return a fail code, just a value of != 0

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Re^3: Perl Module Object - Return fail/success with a fault string by BrowserUk (Patriarch) on Jan 03, 2012 at 19:56 UTC
The problem is that `!` does not provide a numeric context. `use Scalar::Util qw[ dualvar ];; sub alwaysFails { return dualvar 0, 'Some text to explain the error'; +};; $rv = alwaysFails();; print "Sub failed with error: $rv" if !$rv;;` [download] If you want 0 to stand for failed, you'd need to use a test that does provide a numeric context. Eg. `print "Sub failed with error: $rv" if ! 0+$rv;; Sub failed with error: Some text to explain the error print "Sub failed with error: $rv" if ~$rv;; Sub failed with error: Some text to explain the error print "Sub failed with error: $rv" if $rv == 0;; Sub failed with error: Some text to explain the error` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply] [d/l] [select]

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Re^3: Perl Module Object - Return fail/success with a fault string
by BrowserUk (Patriarch) on Jan 03, 2012 at 19:56 UTC

The problem is that ! does not provide a numeric context.

use Scalar::Util qw[ dualvar ];;

sub alwaysFails { return dualvar 0, 'Some text to explain the error'; 
+};;

$rv = alwaysFails();;

print "Sub failed with error: $rv" if !$rv;;
[download]

If you want 0 to stand for failed, you'd need to use a test that does provide a numeric context. Eg.

print "Sub failed with error: $rv" if ! 0+$rv;;
Sub failed with error: Some text to explain the error

print "Sub failed with error: $rv" if ~$rv;;
Sub failed with error: Some text to explain the error

print "Sub failed with error: $rv" if $rv == 0;;
Sub failed with error: Some text to explain the error
[download]

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

The start of some sanity?

[reply]
[d/l]
[select]