Evan’s posterous

to begin to properly secure your linux computer with ssh your sshd configuration file should contain the lines below.  These lines prevent root access, force public key authentication (no password to crack) and restrict access to named users only.

PermitRootLogin no

PasswordAuthentication no

RSAAuthentication yes

PubkeyAuthentication yes

AllowUsers babyman evan

touch temp -t 200910011130

touch ntemp -t 200910011630

find / -cnewer temp -and ! -cnewer ntemp

nmap -sT -O localhost

netstat -an

lsof -i

the following command will sort and show all of the rpm packages installed on a computer using less

rpm -qa | sort | less

ever wonder what the IP address of that server in the corner is, you could always try scanning your network for computers using nmap.

sudo apt-get install nmap

to scan for running computers, here using sudo is optional but will provide more information, all others require root privileges

<sudo> nmap -sP 192.168.1.1/24

to scan for open ports on a computer

sudo nmap -sS 192.168.1.1/24

to include open ports and operating system information

sudo nmap -O 192.168.1.1/24

if you use a mac and have made spotlight part of your workflow GNOME + Do (http://do.davebsd.com/) is really worth a look

#!/bin/bash
 
if [[ "$#" == 1 && -f $1 ]];
then
 # replace with something functional like 'rm -f $1'!
 echo "file $1 exists"
else
 echo "Usage: $0 "
fi

rsync is a great way to copy files between computers as it can continue after partial copies and update directories when only a few files have changed, it also supports secure file copies over ssh as shown below:

copy files locally:

rsync -rtvzP --delete --exclude=.Trash /Users/evan/ /Volumes/backup/evan/

copy local files to a remote computer excluding all the mac .DS_Store folders in the path:

rsync -ravzP --exclude=**/.DS_Store -e ssh "/Users/evan/my files/" evan@someserver.codepit.ca:/home/evan/files/

copy remote files onto a local computer:

rsync -ravzP -e ssh 10.10.238.123:"/home/evan/my files/" /Users/evan/files/

NOTE the use of " when there is are spaces in the file paths

Useful switches:

-n == dry run, very useful with --delete :o
--delete == delete files when they are missing from the source computer and present on the target

So I don't have a dedicated keyboard for my mythtv and I hate to connect one for those little maintenance operations, one solution is to use http://synergy2.sourceforge.net/. Heres how I set it up on my dell mini9 and mythtv server;

install synergy on both systems:

sudo apt-get install synergy

edit the host file and ensure both computers can find each other: 

sudo vim /etc/hosts 

on the laptop something like this:

xxx.xxx.xxx.xxx myth

and on the mythtv server something like this: 

xxx.xxx.xxx.xxx mini9 

create a synergy configuration file on the laptop: 

sudo vim /etc/synergy.config 

section: screens
 mini9:
 myth:
end
section: links
 mini9:
  right = myth
 myth:
  left = mini9
end

start the server on the laptop (-f keeps the server in the foreground for logging/testing purposes):

synergys -f

now start the client end on the mythtv system (also in foreground mode):

synergyc -f mini9

make sure the 2 systems can communicate and that the mouse pointer can move from one system to the other. Set the synergy client to start when the mythtv user logs in: 

go to system -> preferences -> sessions in X and add a new command to run on login:

synergyc mini9

restart the mythtv server and make sure everything starts up correctly, now when you need to access your mythtv system using a mouse and keyboard you can do so from the comfort of your couch my starting the "synergys" server on your laptop.