Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
The author warns that a string like "$a" does variable interpolation. No surprise there. Then he say's "But you now know that "a" can be replaced ba a block as long as it returns a reference to a scalar..." and so we should be worried about someone filling a variable with {system('/bin/rm -rf /*')} and maybe doing 'bad things' to us.

In my humble opinion, by his statement, "a" can be replaced, the original author may be discussing literally replacing the letter 'a' in the expression, "$a", with an actual (curly brace-delimited) block of code; in other words, changing the expression (quotes and all), "$a" to the different other expression, "${system('/bin/rm -rf /*')}", not necessarily assigning such a string as "{system('/bin/rm -rf /*')}", to the variable, $a and interpolating that.

I by no means intend, by posting this reply, to minimize the importance of the interpolation discussions. Nor is it my purpose to cast a pall on any of the extemely pertinant, valid points made in any of those threads.

However, the questions being discussed do not seem to me to be addressing the behavior described (as I read it) by the original author (not that it was especially well written). Perhaps all is right with the world and interpolation is, in fact, predictable.

dmm


You can give a man a fish and feed him for a day ...
Or, you can teach him to fish and feed him for a lifetime

In reply to Re(dmm): Trojan Horse? (taint mode) by dmmiller2k
in thread Trojan Horse? (taint mode) by IraTarball

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!
  • 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, 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, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others having an uproarious good time at the Monastery: (7)
    As of 2014-12-25 07:29 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      Is guessing a good strategy for surviving in the IT business?





      Results (159 votes), past polls