What does the special variable $@ mean in Perl?

Question

I'm trying to understand the following piece of code:

sub foo {
    ...
    if ( $@ ) {
        ...
        die $@;
    }
}

A tip: for the squiggly variables that look like pure punctuation, visit `perldoc perlvar`. — Telemachus, Jul 30 '09 at 22:29
possible duplicate of http://stackoverflow.com/questions/2578671/where-can-i-find-information-about-perls-special-variables — Sinan Ünür, Apr 05 '10 at 13:49

score 13 · Accepted Answer · answered Jul 30 '09 at 17:53

perldoc -f eval:

If there is a syntax error or runtime error, or a "die" statement is executed, an undefined value is returned by "eval", and $@ is set to the error message. If there was no error, $@ is guaranteed to be a null string.

See also perldoc perlvar.

score 3 · Answer 2 · edited Jul 30 '09 at 20:45

3

$@ is a magic variable containing the error message of the last eval command, if any.

edited Jul 30 '09 at 20:45

brian d foy

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answered Jul 30 '09 at 17:55

Nick Lewis

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score 0 · Answer 3 · answered Mar 07 '11 at 14:54

0

The if loop should be preceded by eval for it to be able to trap $@.

During an eval(), $@ is always set on failure and cleared on success.

In case whr code inside eval() did not compile, $@ is set to the compilation error.

answered Mar 07 '11 at 14:54

angel_007

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6

What does the special variable $@ mean in Perl?

3 Answers3