Random background

I've make up a script to set a random background onto the root window. You must initialize the variable DIR to your backgrounds path.

#!/bin/sh
# This script helps to set a random background from $DIR onto the root window

DIR="$HOME/picture/Fonds/"
RES=$(xwininfo -root|grep geometry|cut -d' ' -f4|cut -d+ -f1)
MAX=$(find $DIR -type f | wc -l)
NUM=$((RANDOM%MAX+1))
BACKGROUND=$(find $DIR -type f | head -n $NUM | tail -n 1)
TEST=$(identify "$BACKGROUND" | grep "$RES " | awk '{print $1}')
test ! -z "$TEST" && xsetbg "$BACKGROUND"  || $0

You can modify it as you want, for instance comment RES to take all the backgrounds, even smaller or larger than your screen resolution, or set options to xsetbg like -fullscreen.

SSH through Apache Proxy

If you want to connect you to your beloved SSH server, but you are stick behind a proxy which has only ftp, http, and https open, then you can install proxytunnel. It is a super tool :)

1) You will need apache on port 80 to "proxy" your SSH connection. 2) Create an "easy-to-run" ssh client. I assume you know how to install Apache webserver... so go open/create your VirtualHost.

For Apache you will need the modules mod_proxy (splitted into two files in the httpd tarball: mod_proxy.c and proxy_util.c) and mod_proxy_connect (to allow SSL connections). I use the Apache2 Debian package, so all this stuff is really simple.

Apache configuration example:

NameVirtualHost nameserver_or_ip:80
<VirtualHost nameserver_or_ip:80>
    ProxyRequests on
    ProxyVia on
    AllowCONNECT 22 5554 # by default SSH listens 
                         # on 22, but you can also 
                         # make it listen on a secret 
                         # port for example like 5554;
    <Proxy *>
        Order deny,allow
        Deny from all # By default reject everyone
        Allow from localhost
        Allow from the_fixed_ip_of_your_university
    </Proxy>
    ProxyPass /debian http://ftp.fr.debian.org/debian/ 
        # A useless example of ProxyPass to show how 
        # to be able to connect to the debian ftp since 
        # http://your_host/debian/

    Redirect / http://www.somewhere.com/
</VirtualHost>

Restart your server.

Now edit ~/.ssh/config and get inspired from the next lines:

Host proxy
    DynamicForward 1080
    ProxyCommand proxytunnel -v -p localhost:81 -r myhost:80 -d localhost:13375
    ServerAliveInterval 30

-v is verbose, -p is the proxy to use (the one of your university for example), -r is the remote proxy (your Apache server), and -d is the SSH server to connect to. Note that if your SSH server is on the same as Apache, you can connect to localhost. However I prefer to put the DNS of my server so the message "Last login from" is less ambiguous.

Save this file and exit. Now you can type `ssh proxy' to connect through the hell of proxies.

Screenshot of an SSH connection through a local Apache proxy through a remote Apache proxy:

lapt0p[100]:~% ssh local
localhost is 127.0.0.1
Connected to localhost:81
Tunneling to myhost:80 (remote proxy)
Connect string sent to Proxy: 'CONNECT myhost:80 HTTP/1.0
Proxy-Connection: Keep-Alive

'
DEBUG: recv: 'HTTP/1.0 200 Connection Established
'DEBUG: recv: 'Proxy-agent: Apache/2.0.55 (Ubuntu)
'DEBUG: recv: '
'Tunneling to localhost:13375 (destination)
DEBUG: Send: 'CONNECT localhost:13375 HTTP/1.0
Proxy-Connection: Keep-Alive

'
DEBUG: recv: 'HTTP/1.0 200 Connection Established
'DEBUG: recv: 'Proxy-agent: Apache/2.2.3 (Debian)
'DEBUG: recv: '
'Starting tunnel
Linux myhost 2.6.15-1-amd64-generic #2 Mon Mar 20 10:43:41 UTC 2006 x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Wed Dec 13 21:19:24 2006 from localhost
myhost/ssh[45]:~%