But requiring a word character (\w+) will fail to trim off spaces in the case where the 45th character is a space character and the 46th character is a word character. I think my solution works correctly... can you give an example where it doesn't? Here are some boundary cases that work as they should, using one-character words as you suggested: 
@words = (
#         1         2         3         4         5
#12345678901234567890123456789012345678901234567890
"The quick brown fox jumped over the lazy d I own",
"The quick brown fox jumped over the lazy do I own",
"The quick brown fox jumped over the lazy dog I own",
"The quick brown fox jumped over the lazy dogs I own",
"The quick brown fox jumped over the lazy doggy I own",
);

for my $word (@words) {
  if (length $word > 45) {
    my $forty_sixth = substr($word, 45, 1);
    $word = substr($word, 0, 45);
    $word =~ s/\s*\w*\z// if $forty_sixth =~ /\w/;
  }
  print "Word: '$word', Length: ", length $word, "\n";
}

[download]
produces: 
Word: 'The quick brown fox jumped over the lazy d I', Length: 44
Word: 'The quick brown fox jumped over the lazy do I', Length: 45
Word: 'The quick brown fox jumped over the lazy dog', Length: 44
Word: 'The quick brown fox jumped over the lazy dogs', Length: 45
Word: 'The quick brown fox jumped over the lazy', Length: 40

[download]

In reply to Re: Re: Re: regexp word break help by thelenm
in thread regexp word break help by nop

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.