All commands

this will increase the volume by 2 decibels on the pcm channel. the argument to -c is for which sound card to use, the arg after set is the channel (PCM, Master, etc.) and what to set by.

related commands:

amixer -c 0 set PCM 2dB-

decrease volume by 2 decibels

amixer -c 0 set PCM toggle

toggle mute/unmute

this is for alsa systems

for mac os (and maybe other UNIX systems) osascript -e 'set Volume *' where * is any number (can have decimal points) between 0 and 10

This is equivalent to: less `which rcsyslog`

-bash: /bin/grep: Argument list too long

20090119.00011.log:DANGEROUS ERROR

after a terminal gets clobbered (like after you cat a binary file by accident), this is the only way to get it back without re-starting it.

It takes a hunk and shows the different between the three file. Useful when you want to compare two different changed file which from the same base file.

(use emacs ediff3, eyecandy and more useful if you want to merge them from anywhere to anywhere)

The file myfile is owned by tom and has read and write permissions for tom. Group and other permissions are empty which make myfile readable and writable only by tom. setfacl enables user tom to give read permission to user john only. The command 'ls -l' shows a '+' sign telling us that file access control list has been setup for myfile.

works like a charm for the K610i

greps for search word in directory and below (defaults to cd).

-i case insensitive

-n shows line number

-H shows file name

I often need to send screenshots to other people to explain settings and whatever.

So I created this oneline which I use to create the screenshot with imagemagik, upload it via scp to my server and then the command opens an firefox tab with the screenshot.

The screenshot can be a region or a window.

You just have to replace the parts beginning with YOUR.

Good for automating reports that need to run from between two dates.

the -A argument forwards your ssh private keys to the host you're going to. Useful in some scenarios where you have to hop to one server, and then login to another using a private key.

kills all pids matching the search term of "PROCESS". Be careful what you wish for :)

queries local memcached for stats, calculates hit/get ratio and prints it out.

Ran as the postgres user, dumps each database individually. It dumps with the create statements as well, so you can just 'zcat $x-nightly.dmp.gz | psql' to reimport/recreate a database from a backup.

Find files that are older than x days in the working directory and list them. This will recurse all the sub-directories inside the working directory.

By changing the value for -mtime, you can adjust the time and by replacing the ls command with, say, rm, you can remove those files if you wish to.

mtr combines the functionality of the traceroute and ping programs in a single network diagnostic tool.

As mtr starts, it investigates the network connection between the host mtr runs on and HOSTNAME. by sending packets with purposly low TTLs. It continues to send packets with low TTL, noting the response time of the intervening routers. This allows mtr to print the response percentage and response times of the internet route to HOSTNAME. A sudden increase in packetloss or response time is often an indication of a bad (or simply over‐loaded) link.