Finding the text in URL with PHP.

Yesterday I was working on a script to validate reciprocal links directory redribera . The truth is that this is a utility which by default is implemented in most commercial scripts directory as phpLD or k-Links. However red ribera directory is a directory of his own making, and the functionality of the changes according to the requirements of maintenance. This is an advantage because it makes it very flexible to the needs that arise for me right administration. Clutchless the problem of its programming, which requires the knowledge of programming. Originally the board caught sending requests for links to the directory by using the links application form (to the right you can see a partial sample, where the field is highlighted to indicate the URL of reciprocal link). This information is provided by an applicant and stored in a database, where after an editor (myself) to conduct the review or approval.

Like many folders, the long redribera began requiring a reciprocal link to validate an application. Is the minimum required to make the effort of editing applications and the inclusion in a directory already consolidated. However, the content of this field on the form was not validated by no means automatic, but after human review by an editor. To this day the number of applications that support the board is quite high, although most of them either did not indicate a URL where the reciprocal link, or in the URL provided there is nothing, having lost considerable time to perform the validation by the editor.

So I spent some time in developing a php function that allows me to validate the existence of a text in a given URL (if any).

Code:

---

<? Php


validaLinkReciproco function ($ feedURL, $ searchString) {
/ * Used to validate the reciprocal link.
Who use this script, probably by an include
Returns: true (string found), false (string not found) * /

/ / First check if curl is installed on the web server.
$ CurlInstalled = true;

if (! extension_loaded ('curl')) {
if ( strtoupper ( substr (PHP_OS, 0, 3)) === 'WIN') {
if (! dl ('php_curl.dll')) {/ / Attempt to load the extension for Windows systems
$ CurlInstalled = false;
Else {}
$ CurlInstalled = true;
}
Else {}
if (! dl ('curl.so')) {/ / Attempt to load the extension for POSIX systems
$ CurlInstalled = false;
Else {}
$ CurlInstalled = true;
}
}
}

/ / Depending on whether you installed curl, we obtain the data one way or another
if ($ curlInstalled == true) {
/ / Retrieve data from curl
$ OhYeah = curl_init ();
curl_setopt ($ OhYeah, CURLOPT_RETURNTRANSFER, 1);
curl_setopt ($ OhYeah, CURLOPT_URL, $ feedURL);
$ Err = curl_error ($ OhYeah)
$ Pagedata = curl_exec ($ OhYeah)
curl_close ($ OhYeah)
Else {}
$ Pagedata = file_get_contents ($ feedURL);
}

/ / Find the string in the string
$ Pos = strpos ($ pagedata, $ searchString);

if ($ pos === false) {
/ / String $ searchString $ feedURL not found in
return false;
}
else {
/ / String $ searchString $ feedURL found in
return true;
}
}
?>;

---

This is obviously a function that should be used in the paragraph to validate the data submitted by the form, where $ feedURL, should contain the URL where you want to search (in our case given by the reciprocal link URL field - see the image above). The function returns true or false, depending on who is the search string in the HTML of the page listed for $ feedURL.

This function is a generic, ie not looking for the existence of a reciprocal link in a URL, but any text so it can be reused for many uses that a webmaster wants to give. In our case, just look for the existence of the web link text, for example, $ searchString = "dominio.com", however it can force the searches much more, to validate the entire label and make sure for example that the applicant refers to our Web supply the exact text, thereby avoiding surprises like nofollow links, etc .... In my case, this simple addition to the directory prevents me reviewing a number of applications that do not comply with the policy of inclusion in the directory redribera. Of course, every law, a loophole, but I will leave that for another post ....

I hope you can be useful to me as it has.