Actually the eval { ... }; if ($@) { ... } pattern is dangerous. Consider this example: 

use 5.010;
use strict;
use warnings;

sub DESTROY { eval { "no error here" } }

eval {
    my $x = bless {};
    die "an error here";
};

say $@ ? "ERROR" : "no error caught";

[download]

This reports no error caught, because $x goes out of scope, the DESTROY method is called, which in turn executes an eval that rests $@. Hooray for global variables. (This is one of the reasons that Perl 6 has context variables instead).

A safer meme is 

my $success = eval { ...; 1 }

[download]

So back to the question, what's the difference? It's that in the case with eval and if the code doesn't work as expected if some DESTROY method forgot to localize $@.

In reply to Re: Why <c>eval {...};if ($@) { die $@ } else { ...</c> ??? by moritz
in thread Why <c>eval {...};if ($@) { die $@ } else { ...</c> ??? by Jenda

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.