In this article , we'll see how to install or upgrade libcurl to a new version ( 7.15.3 ) and then integrate it to the PHP running in the server. Following steps were successfully tested on a Plesk 7.5 server running on RHEL-3.

1 Install libcURL

LibcURL is under GPL. It can be downloaded from http://curl.haxx.se and installed freely.

1.1 Downloading and compiling of cURL

wget http://curl.haxx.se/download/curl-7.15.3.tar.gz
tar -xzf curl-7.15.3.tar.gz
cd curl-7.15.3
/configure
make
make install

On successful compilation, curl is installed to /usr/local/ directory.

1.2 Installing a CA cert bundle for curl

Accessing secure sites ( https ) through cURL requires a list of certifying authorities to be available for curl.

There are many a ways to get the latest ca-bundle, and the curl developers themselves provide one at

http://curl.haxx.se/ca/cacert.pem

/usr/local/share/curl/curl-ca-bundle.crt

/usr/share/ssl/certs/ca-bundle.crt

$curl-config -ca

$ wget http://curl.haxx.se/ca/cacert.pem
$ mv /usr/local/share/curl/curl-ca-bundle.crt /usr/local/share/curl/curl-ca-bundle.crt.old
$ mv cacert.pem /usr/local/share/curl/curl-ca-bundle.crt

1.3 Testing curl binary

To test the cURL binary, give a URL as its argument and see the output. Along with the webpage which it downloads, curl binary also lists statistics of data transfer. A sample output is as shown below.

$ curl http://www.yahoo.com > test.txt

%
Total
%
Received
%
Xferd
Average Dload
Speed Upload
Time Total
Time Spent
Time left
Current Speed

100
32420
0
32420
0
0
14676
0
-:-:-
0:00:02
-:-:-
41571

2 Integrating with PHP

To integrate with PHP (assumed to be already running on the server), perform the following steps.

• Download the php sourcecode from http://php.net
• Untar and cd php-X.X.X
• In your configure command , add "-with-curl=/usr/local''. Php looks for the include/curl/ inside the directory we give here, when configuring.
  ( tip: To make sure that existing configuration is not lost, get the configure command from phpinfo() )
• make && make install.
• restart apache.

2.1 Testing PHP with cURL

To test if php with cURL is working correctly, use the test script available at php.net/curl.

<?php

        $ch = curl_init("http://www.example.com/");

        $fp = fopen("example_homepage.txt",
"w");

        curl_setopt($ch, CURLOPT_FILE, $fp);

        curl_setopt($ch, CURLOPT_HEADER, 0);

        curl_exec($ch); curl_close($ch); fclose($fp);
?>

3 References

• Curl developers homepage
• PHP.net