This wiki is here primarily as a dumping ground for system administration information, tricks etc which I’ve gathered over the years and which might be helpful to other people. It also includes documentation useful for the people who use this server for their own things.
count_same_lines - This script counts lines on STDIN which are the same. It has some output options to make life easier. Very handy for log analysis.
get_env_of_pid - Prints the environment variables set for a running process. Useful when wrapper scripts are doing non-obvious things to LD_LIBRARY_PATH and the like. Basically it just looks in /proc/<pid>/environ and splits on \000.
get_id_of_pid - Prints an ‘id’ like output for a process id. Useful when used on long running processes when the group assignments have changed.
machinenames - This script uses a zone file and dns AXFR queries to list all the different names for a host. Very handy when you have a lot of machines with different function names (imap,pop,smtp,mysql etc)
rcsedit - I thought I’d have to rewrite this tool myself, but actually you can get it from here...
http://lava.net/rcsedit/. I’ve extended it to add features to really make it useful. With my aditions it should be easier to convince people to use it as it makes their lives easier when they are making a change rather than just when they fuck something up.
dnsedit - A wrapper for rcsedit so you can just type
dnsedit zonino.org to edit the zone file for zonino.org. Needs the top few variables tunes for your environment.
wait_for_x - This script will wait for a specified PID of file to disapair and then run a command. Helpful if - for example - you are waiting for a user to close an application before running a simple command. Or if you just want a really cheap nasty one-off service down notification.
