These snippets of code can be used to check if an URL is valid or not and with some changes it can get URL's from a text.
"In general URI's as defined by RFC 3986 (page 12) may contain any of the following characters: A-Z, a-z, 0-9, -, ., _, ~, :, /, ?, #, ,, @, !, $, &, ', (, ), *, +, ,, ; and =. Any other character needs to be encoded with the percent-encoding (%hh). Each part of the URI has further restrictions about what characters need to be represented by an percent-encoded word." (Gumbo, 2009)
#
# Check if an URL is valid or not...
#
set blabla {http://www.ietf.org/rfc/rfc3986.txt}
if {[regexp -- {^(https?://[a-z0-9\-]+\.[a-z0-9\-\.]+(?:/|(?:/[a-zA-Z0-9!#\$%&'\*\+,\-\.:;=\?@\[\]_~]+)*)))$} $blabla match url]} {
puts "$url is a valid url."
}
#
# Getting an URL from a HTML code...
#
set blabla {<div class="title">Edit <a href="http://wiki.tcl.tk/26255">URL Parser</a></div>}
if {[regexp -- {(https?://[a-z0-9\-]+\.[a-z0-9\-\.]+(?:/|(?:/[a-zA-Z0-9!#\$%&'\*\+,\-\.:;=\?@\[\]_~]+)*)))} $blabla match url]} {
puts "$url found in the HTML code."
}Let's test it and post the results here...
PS: It doesn't work for IPv6 yet.