curl_init causes error on specific web pages - php

Question

If a server has the function "curl_init" disabled, would that cause an error number 7 and the error message: "couldn't connect to host" or is there another reason why I am getting this error?
And if it is a security issue is there a way around this since I do not have control over the security of these websites?
<?php
$url = $_POST["url"];
$url = $url.'/';
echo "<br> <b>URL: </b>".$url;
function get_web_page($url)
{
$options = array(
CURLOPT_RETURNTRANSFER => true, // return web page
CURLOPT_HEADER => false, // don't return headers
CURLOPT_FOLLOWLOCATION => true, // follow redirects
CURLOPT_ENCODING => "", // handle all encodings
CURLOPT_CONNECTTIMEOUT => 120, // timeout on connect
CURLOPT_TIMEOUT => 120, // timeout on response
CURLOPT_MAXREDIRS => 10, // stop after 10 redirects
//CURLOPT_PROXY => "localhost:80",
);
$ch = curl_init( $url );
curl_setopt_array( $ch, $options );
$content = curl_exec( $ch );
$err = curl_errno( $ch );
$errmsg = curl_error( $ch );
$header = curl_getinfo( $ch );
curl_close( $ch );
$header['errno'] = $err;
$header['errmsg'] = $errmsg;
$header['content'] = $content;
$html= get_web_page($url);
echo '<br> <b>Error Number: </b>'.$html['errno'];
echo '<br> <b>Error Message: </b>'.$html['errmsg'];
?>
I hope this is enough code to work off of.
This is the site im working on. At the bottom you should be able to enter any URL. If you put www.csun.edu it gets that error. But if you put library.csun.edu it does not.
http://www.csun.edu/~ppm90976/profilepoojamanjrekar.html

Answer 1

Could you please give your code? I will try to answer your question, but based on your question, I'm not sure if I can.
curl_init() is a native function since PHP4. Unless I'm mistaken, it can't be disabled. On top of that, if it were to be disabled, it wouldn't present a 'couldn't connect to host' (errno:7) error.
So what I think you meant to ask is what would happen 'if the remote server doesn't have it enabled'. This question is actually moot, since what curl does is basically 'fetch' a page, when visiting another site/ page under specific conditions. As long as a web page is viewable under the conditions you set (using the curl_setopt() function), it will work.
Now, what I recall is that the error number 7 could happen if the page you requested has a redirect and your curl options specify that it should not follow redirections. To check if this is the cause of your issue, set this option before you execute the url:
curl_setopt('CURLOPT_FOLLOWLOCATION', true);
Let me know if that helped.