PHP replace string after using file_get_contents

问题:

Hi I am looking to replace words in an html email I am loading via file_get_contents

Here is my code:

<?

$message = file_get_contents("http://www.MYwebsiteExample.com/EmailConfirmation.php");


$message =  preg_replace('/SAD/', "HAPPY", $message);
// Also tried this below and it does not work either
 $message = str_replace('/SAD/', "HAPPY", $message);

?>

I am hoping to find all the patters of SAD (case sensitive) and replace them with HAPPY. For some reason if I use file_get_contents it doesn't seem to be working.

Thanks

UPDATE: Jan 22, 2013

Actually, sorry Correction when I add the $ it does not work. Its not necessary for my code. I can do a work around but this does not work below:

$message = str_replace("$SAD", "HAPPY", $message); /// does not work. Not sure why
$message = str_replace("SAD", "HAPPY", $message); /// without the $ it does work.

回答1:

$message = str_replace("$SAD", "HAPPY", $message);

needs to be:

$message = str_replace('$SAD', "HAPPY", $message);

Otherwise PHP will interpret it as the variable $SAD. See this post for an explanation on the difference between single and double quotes.

回答2:

You shouldn't use regular expressions for this; it's simple string replacement:

$message = strtr($message, array(
    '$SAD' => 'HAPPY',
));

Btw, if you use "$SAD" for the search string, PHP will try to evaluate a variable called $SAD, which doesn't exist and will throw a notice if your error_reporting is configured to show it.