Development regular expressions in PHP

I want to make an if(){} statement that says if string $link starts with 'http://' then
echo("<a href='" . $link . "'>Blah blah</a>");
otherwise,
echo("<a href='http://www.unm.edu/~cjadams/forms/info/" . $link . "'>Blah blah</a>");

I just noticed not all of our info pages are stand alone pages that I can copy to their own directory, some actually branch out.

I know this can be done with regular expressions, or maybe without, but how can I test the first seven characters of a string for "http://" ? I know there must be an easy way, right?

 

eregi() is your ultimate friend, gimme 10 mins and i'll post some code (if i can work it out).

I'd go for the easier explode() method...

Code:

$urlparts = explode(':',$string);

if($urlparts[0] == 'http') {

        echo [world link]

}else {

        echo [local link]
}

 

My end result:

PHP:

if (!$row['InfoLink']){
    echo("<td width='16'><img src='http://www.unm.edu/~cjadams/images/spacer.gif' width='16'></td>");
} else {
    $info = $row['InfoLink'];
    if (substr($info, 0, 7)=="http://"){
        echo("<td width='16'><a href='" . $row['InfoLink'] . "' target='_Blank'><img src='http://www.unm.edu/~cjadams/images/icon_info.gif' border='0'></a></td>\n ");
    } else {
        echo("<td width='16'><a href='http://www.unm.edu/~cjadams/forms/info/" . $row['InfoLink'] . "' target='_Blank'><img src='http://www.unm.edu/~cjadams/images/icon_info.gif' border='0'></a></td>\n ");
    }
}


It works, so I'm happy
Is there a shorter way than 0,7? just curious.

 

or using strstr ...

Code:

if(strstr($string, 'http://')) {

        echo '<a href="'.$_POST[url].'">blah...</a>';
        
} else {

        echo '<a href="http://richthetitch.net/'.$_POST[url].'">blah..</a>';
}

but much less reliable as it wont check that the first part is http://, it only knows if the string contains http://.

 

In this instance it would be fine, because an http:// anywhere in a url other than at the first will mess it up anyway.

But I'm sticking with my first way for now. I had to paste the code in like 20 places.

I just found out I should be using a while or for loop instead of pasting the same code 6 times, with the only difference being a little bit of text and a number!

Thanks though, I'll go with your first reccomendation when I clean my code!

 

you can cut those down a little more, using shorthand if statements

Code:

rah == 1 ? true : false;

you can nest them as well

Code:

rah == 1 ? true
               : rah == 2 
               ? true
               : false;

iirc...

 

Yup, another trick I learned from linear. Isn't that the if syntax in C/#/++?

 

its the same as the syntax is any language ive used, seen it in c/perl/php/javascript seems pretty common. Yer granted i missed the $ off the variables, been reading about c recently

 

if(!preg_match("/^http:\/\//i", $link)) $link = "http://".$link.


i think that's it. i may have escaped the forward slashes wrong.


in the php tags on this forum it shows \/ as /. why does that happen? see below

PHP:

\/