cURL / Mailing Lists / curl-library / Single Mail


Re: multi-interface

From: Emil Romanus <>
Date: Wed, 1 Aug 2007 16:57:03 +0200

2007/8/1, Peter Thiess <>:
> Hi everybody,


I'm a newbie in curl and I read about the multi interface; can anybody
> clarify if this is a stacking mechanism or if this ptarallelizes file
> transfer (e.g. multi-channel FTP) internally. I am thinking of ways to
> speed up FTP.

Multi-channel? Do you mean multiple connections or multiple requests through
one connection? libcurl will determine if it should reuse existing
connections or make new ones. It's probably a matter of protocol and
settings. For example, if HTTP pipelining is enabled and you are requesting
multiple URLs through HTTP to the same server, the same connection will most
likely be used for each transfers.

When it comes to FTP, it probably depends on passive and active mode. I also
think it depends on if you are downloading a file or listing a directory. I
do not think libcurl would connect multiple times to the same server to list
for example three different directories according to three curl easy

If you are communicating with one FTP server I believe using a multi handle
would be a better choice than running the easy handles on their on, since
libcurl will determine how to do the communication in the most efficient (I
guess) way.

I *think* that if you are downloading files you will always get a separate
connection for each file (FTP). Someone please correct me if I'm wrong.

Received on 2007-08-01