You are correct the x* modifier means as much of x as possible to make a match. x*? means as little of x as possible including no x at all. It is similar for x+ and x+? except x+? must have at least one x. See perlman:perlre for more details. Here is a relevant chunk:

The following standard quantifiers are recognized: 


    *      Match 0 or more times
    +      Match 1 or more times
    ?      Match 1 or 0 times
    {n}    Match exactly n times
    {n,}   Match at least n times
    {n,m}  Match at least n but not more than m times

(If a curly bracket occurs in any other context, it is
treated as a regular character.) The ``*'' modifier is
equivalent to {0,}, the ``+'' modifier to {1,}, and the
 ``?'' modifier to {0,1}. n and m are limited to integral
values less than 65536. 

By default, a quantified subpattern is ``greedy'', that is,
it will match as many times as possible (given a particular
starting location) while still allowing the rest of the
pattern to match. If you want it to match the minimum
number of times possible, follow the quantifier with a
``?''. Note that the meanings don't change, just the
``greediness'': 


    *?     Match 0 or more times
    +?     Match 1 or more times
    ??     Match 0 or 1 time
    {n}?   Match exactly n times
    {n,}?  Match at least n times
    {n,m}? Match at least n but not more than m times


cheers

tachyon

s&&rsenoyhcatreve&&&s&n\w+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print


In reply to Re: How Greedy is Greedy: A Regex Question by tachyon
in thread How Greedy is Greedy: A Regex Question by dsb

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.