The character limiter plugin, which comes with EE by default, is also “word smart”, meaning that it does not limit a string to an exact length, but will add one word at a time until the limit is exceeded. Since a URL has no spaces, it is all one “word”. Also, if your link is auto-converted, then you’re passing a fully marked up link to the plugin, not just the address, so a simple “true” character limiter will not work either.
<a href="http://example.com/">http://example.com/</a>
Forcing this to 35 characters would yield a broken link:
<a href="http://example.com/">http://
__I’m afraid the solution is a bit more complex. Option one is easier to implement, but would require that your set the {link_address} field’s formatting to “None”, and that you disable the auto-conversion of links for this weblog. Then you could turn PHP on Output in the template (or create a simple plugin) and do the following:__
<a href="{link_address}"><?php if (strlen('{link_address}') > 35): echo substr('{link_address}', 0, 35).'…'; else echo '{link_address}'; ?></a>
The second option would be to create an extension that would automatically rewrite auto-created links in a truncated fashion as necessary.