It seems you want a window x words big? 

@words=$text_body =~ /(\S+)/g;
#compute $start and $end
$newtext=join(" ",@words[$start..$end]);

[download]

Update:Without copying. Note: I could not get the foreach deal to work at all so had to use while with a counter. 

# $start and $window

$i++ while($i<$start && /(\S+\s+)/g);

$i=0;
while(/\G(\S+\s+)/g && $i<$window_length)
{
    $newtext .= "$1";
    $i++;
}

[download]

Note also: Two types of while. Probably should pick one you like the best and standardize on that.

This skips the $start number of words and the assigns $window_length words to $newtext preserving whitespace

Another Update: $start of 0 was not working but reversing the tests in the first while fixes that.

In reply to Re: Slicing a string on words by dga
in thread Slicing a string on words by dstar

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.