Can you post some code for solutions you've attempted so we can work from there? My initial thoughts are that you can just tweak the regex to exclude an optional trailing period. maybe something like: 
while(<DATA>){
  s#(https?://\S+?)(\.?\s)#<a href="$1">$1</a>$2#igs;
  print;
}
__DATA__
Students can activate their UMSIS userids on-line by filling out and s
+ubmitting the form at https://umsis.miami.edu/sign-up.
...which can be obtained via the web at http://www.miami.edu/it-forms/
+.

[download]

In reply to Re: replace url in text with html link by davidrw
in thread replace url in text with html link by thealienz1

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.