There are two kinds of eval:
  1. eval STRING

    This takes a piece of string and executes it as Perl code. This is the bad kind.

  2. eval BLOCK

    This is Perl's equivalent for try/catch in other languages, and there's nothing wrong with it.

What kind of eval are you talking about?

update Duh! You're talking about executing user supplied code, so of course it's eval STRING.

Well, there's no way to avoid executing user supplied code if you want to execute user supplied code.

Either you eval the input as Perl, or you provide a small language (not Perl) and interpret it, in Perl. The latter is safer, but a lot of work to implement.


In reply to Re: How to avoid eval()? by bart
in thread How to avoid eval()? by emilbarton

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.