CURL

cURL is a computer software project providing a library and command-line tool for transferring data using various protocols. The cURL project produces two products, libcurl and cURL. It was first released in 1997. The name originally stood for see URL .

The website of cURL opens with: A command line tool and library for transferring data with URLs .

What's cURL used for

cURL is used in command lines or scripts to transfer data. It is also used in cars, television sets, routers, printers, audio equipment, mobile phones, tablets, settop boxes, media players and is the internet transfer backbone for thousands of software applications affecting billions of humans daily.

Who makes cURL ?

cURL is free and open source software and exists thanks to thousands of contributors. The cURL project follows well established open source best practices.

Where's the code?

Check out the latest source code from github.

Practical examples

Download a single website

The following command <syntaxhighlight lang="bash" line start="1"> $ curl https://curl.haxx.se </syntaxhighlight> will download the content of the curl website and shows it in the STDOUT.

Save the cURL Output to a file

To save the result of the curl command to a file by using -o/-O options.

• -o (lowercase o) the result will be saved in the filename provided in the command line
• -O (uppercase O) the filename in the URL will be taken and it will be used as the filename to store the result

<syntaxhighlight lang="bash" line start="1"> $ curl -o mygettext.html http://www.gnu.org/software/gettext/manual/gettext.html </syntaxhighlight>

PHP Example

<syntaxhighlight lang="php" line start="1">

// Creates a curl resource $c = curl_init();

// Sets the URI curl_setopt($c, CURLOPT_URL, $URL);

// Sets the return the transfer as a string curl_setopt($c, CURLOPT_RETURNTRANSFER, true);

// Sets the return header curl_setopt($c, CURLOPT_HEADER, false);

// Sets the follow location curl_setopt($c, CURLOPT_FOLLOWLOCATION, true);

// Sets the timeout curl_setopt($c, CURLOPT_CONNECTTIMEOUT, 7); curl_setopt($c, CURLOPT_TIMEOUT, 10);

// Sets the Mozila compliance curl_setopt($c, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible;)");

// Gets the website into a string $response = curl_exec($c);

// Closes the curl curl_close($c); </syntaxhighlight>

See also

• bookcurl.haxx.se is the home of this book by Daniel Stenberg. It features easy accessible links to read the book online in a web version or download a copy for offline reading using one of the many different versions offered, including PDF, ePUB and MOBI.
• Book, The HTML-representation of the the Book.