Tips

create graphs using gnuplot

gnuplot graph (click to enlarge)

GnuPlot helps you to create graphs from data in a file. You can plot your weight, income, CPU-utilization, whatever fits into a file.

want to watch a forbidden video

You want to watch a video, but it is only available for viewers in the USA? See rackspace.

want to get rebate like an American

Rental cars tend to be cheaper if you use a browser with a US IP address. To do this, see rackspace.

don't want this program to start everytime you log in?

Sometimes a program is started when you log in, but you do not want this. To schedule and de-schedule programs from starting, see scheduling tasks.

want to hide your personal data in the internet

If you visit a website, people will know data from you like operating system and location. To prevent this, use tor.

want to connect a USB drive and get instant access

When you connect your USB drive you want it to be accessible somewhere immediately. You do not want to open a console and mount it, you want it to be mounted automatically. See automounter.

analyze system performance

ksar (click to enlarge)

You can analyze system performance using ksar.

rename several files

Rename several files using the command

rename 's/BEFORE/AFTER/g' *

list files by size

To list files ascending by size use the command

du -s * | sort -n

attention, this will not work if you have a file named --help. Also, this command will not include hidden files.

favorite Linux-Tools

history|awk '{print $2}'|awk 'BEGIN {FS="|"} {print $1}'|sort|uniq -c|sort -rn|head -10

controlling several computers at once

ClusterSSH (click to enlarge)

When working in a cluster you can control several computers in one console using clusterssh.

find out which files are accessed by a program

To find out which files are accessed by a program start it with

strace -e open program

find out program that belongs to a window

Sometimes a window pops up and you do not know which program it is. For example you have just created a fresh user and when he logs in, he sees a window that you would like to get rid of. So you need to search where the window's program is called. So, every window is associated with a process. To find that out, call xprop and click on the window you want information about.

# xprop
[...]
WM_CLASS(STRING) = "simple-scan", "Simple-scan"
[...]

find out where configuration changes are stored

See here

convert images in a batch job

Use the command convert:

convert name.format name.jpg

did you know...

...you can allow running vlc as root

To do this, disassemble and edit vlc as described under Gdb#Allow_starting_vlc_as_root.

...you can sort files by size and age

To sort your files and folders by size, open a console and enter:

du -s * | sort -n

To sort your files and folders by age, open a console and enter:

ls -ltr

key codes

... you can find out the key code of every key on your keyboard using the command xev.

split files

...you can split files using the command split.

put computer into standby mode

... you can put your computer into standby mode by opening a console and entering

echo mem > /sys/power/state

Remove red eyes with The GIMP

1. mark the red in the eyes with the magic stick
2. selection -> fade (5px)
3. choose a pen
4. mode "color", opacity 80%, one time
5. mode "overlay", opacity 65%, one time

write something on your screen

...you can write something on your screen using osd_cat.

download youtube videos...

... using http://keepvid.com/, it works with Linux.

watch changes

... you can watch changes, e.g. the size of a file being written with the command watch:

dd if=urandom.img of=test.img & watch --interval=1 "du -h test.img"

See also

• http://www.onpn.de/misc/linuxtipps.txt