checking for existence of http:// data for using in links

ATS16805

some of my tables fields' contain web site link URL's. i have tried to ensure that a URL is entered as i want w/ the inclusion of http:// instead of the web app user simply entereing www.* for the entry by inserting a value in my HTML for, like so

<input type="text" name="web_site" value="http://" />

so when a user comes upon this field, he or she will be more inclined to enter their input data after the [url]http://.[/url].. thereby resulting in a data entry which is in my preferred format. however, i can NOT control whether the user might either accidentally or purposefully remove my preset input value.

so, considering this margin for error, what can i do so that when i'm SELECTing data from MySQL, i can be sure that if i'm going to put any web site URL data into an output string, that it will in fact contain the necessary http:// prefix, as in

$display_block .= "<p>just click <a href=\"$web_site\" >here</a> to follow the link";

would this best be done via MySQL commands or via PHP, or via some function which i must create?

thanks!!

Sxooter

Why not just take both quietly?

<?php
$url = $_POST['incomingurl'];
if (!substr($url,0,7)=="http://"){
    $url="http://".$url;
} else {
    // do nothing.
}

Sxooter

Note that if you wanted to let them enter things like ftp:// or rtsp:// you could use this:

if (!eregi("^{[a-z]+://",$url))} { // add http:// here

Not sure if you need to escape the : or // up there.

ATS16805

Sxooter wrote:

Why not just take both quietly?

<?php
$url = $_POST['incomingurl'];
if (!substr($url,0,7)=="http://"){
    $url="http://".$url;
} else {
    // do nothing.
}

ah! so, this will let them enter either, and fix it automatically if it's not what i want, yes? this is VERY COOL, and not something i was previously aware of. thanks so much, Sxooter!! your way is the best idea i'd think of... i just didnt know how to do it! 😉
(if in fact that's what's going on there)

i'll look it up, but can you tell me any more about why you chose this particular argument structure?:

(!substr($url,0,7)

Sxooter

Well, if the substring of the first 7 characters of the url ARE [url]http://,[/url] we wouldn't need to do anything to it, so we test if it's NOT that... I.e. the ! character means NOT TRUE, or opposite of.