libcurl-easy - easy interface overview
When using libcurl's "easy" interface you init your session and get a
handle (often referred to as an "easy handle"), which you use as
input to the easy interface functions you use. Use curl_easy_init(3)
get the handle.
You continue by setting all the options you want in the upcoming transfer, the
most important among them is the URL itself (you can't transfer anything
without a specified URL as you may have figured out yourself). You might want
to set some callbacks as well that will be called from the library when data
is available etc. curl_easy_setopt(3)
is used for all this.
is only option you really must set, as otherwise there can
be no transfer. Another commonly used option is CURLOPT_VERBOSE(3)
will help you see what libcurl is doing under the hood, very useful when
debugging for example. The curl_easy_setopt(3)
man page has a full
index of the over 200 available options.
If you at any point would like to blank all previously set options for a single
easy handle, you can call curl_easy_reset(3)
and you can also make a
clone of an easy handle (with all its set options) using
When all is setup, you tell libcurl to perform the transfer using
. It will then do the entire operation and won't
return until it is done (successfully or not).
After the transfer has been made, you can set new options and make another
transfer, or if you're done, cleanup the session by calling
. If you want persistent connections, you don't
cleanup immediately, but instead run ahead and perform other transfers using
the same easy handle.