I have had good luck with cURL in the past. If you are on a Linux box, it would be trivial to set up a CRON job to do this update process for you. A good reference for CLI HTTP scripting in cURL can be found here, however you may need the -T flag (for file transport) to accomplish the upload portion. Speaking of uploading, if you can run the script/process/crontab from the server you would like to update, I would recommend downloading from the web server to obviate one trip and a third party. Or, if you need to update on demand, you could write a PHP script that uses the built in PHP cURL functions. If you take the Linux+CLI route, you could also use sftp.
Update: In testing curl with sftp (curl -u uname:pword sftp://domain.tld
) I get the following error: curl: (1) Protocol sftp not supported or disabled in libcurl
on Kubuntu 12.04. So cURL may not be a good idea. I also tested CLI sftp (sftp uname@domain.tld:/dir/file.ext
) but could not find a way (short of using ssh keys) to send authentication. Thus, this would necessarily be a manual process unless you did set up ssh keys between the servers. As it does not sound like you have that kind of access to ExampleSiteB.com, this probably isn't acceptable.
Update 2: Since my initial answer turned out to be of little use, I figured I would expand upon one of the above answers. I was trying to find a solution that did not involve a PECL extension, but I did not have much luck with ftp_ssh_connect(). I recommend trying it, you may have better luck and could forgo the PECL extension route.
Sigh, on further reading, it appears ftp_ssh_connect
is, understandably, incompatible with the sftp protocol. However, I found a nice blog post about utilizing ssh2_connect()
and ssh2_sftp()
(as mentioned in a previous answer) and figured I would post that to give you some additional assistance. It is not as simple as calling the functions for most PHP distributions. Here is the blog post. Some of those steps may not be necessary or you may need to do some additional things listed in another blog post I ran across, here.
On my system, all I had to do was run apt-get install libssh2-1-dev libssh2-php
and I was able to find ssh2 in my php -m
output.