sprintf warning - encoding issue - php

Question

I'm using the following code to find all properties for a user and in turn delete them. My problem is that I'm getting a warning: Warning: sprintf(): Too few arguments for each of the properties.
However, when I manually enter the $user_id for the delete string as first_last%%40ourwiki.com it works!
Seems like sprintf requires double '%' but not sure why. Is there a way to get around this? Also, I'm using the same variable for file_get_contents and this works fine.
The Code:
$user="first_last#ourwiki.com";
$user_id=str_replace(array('#', '#'), array('%40', '%23'), $user);
print $user_id;
$url=("http://admin:password#172.16.214.133/#api/users/=$user_id/properties");
$xmlString=file_get_contents($url);
$delete = "http://admin:password#172.16.214.133/#api/users/=$user_id/properties/%s";
$xml = new SimpleXMLElement($xmlString);
function curl_fetch($url,$username,$password,$method='DELETE')
{
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
curl_setopt($ch,CURLOPT_USERPWD,"$username:$password");
return curl_exec($ch);
}
foreach($xml->property as $property) {
$name = $property['name'];
$name2=str_replace(array('#', '#'), array('%40', '%23'), $name);
print $name2;
curl_fetch(sprintf($delete, $name2),'admin','password');
}
Thanks in advance!

Answer 1

% is a special character in sprintf(). So you have to escape all % before processing it, %% is a literal %s.
$delete = str_replace("http://admin:password#172.16.214.133/#api/users/=$user_id/properties/", '%', '%%').'%s';
You do not have to use sprintf here, you can use the concatenation operator too, like:
$delete = "http://admin:password#172.16.214.133/#api/users/=$user_id/properties/";
curl_fetch( $delete . $name2, 'admin', 'password' );