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Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.
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In Python version 3, the module was merged into http.server. Gentlemen, change your aliases.
The unlock command for KDE 4.3 has changed from krunner_lock, this process doesn't exist anymore. So here's the update :-)
If qdbus complains about not being able to find X, put a "DISPLAY=:0 " (:0 being your X server display) in front of the command.
On a Gentoo system, this command will tell you which packets you have installed and sort them by how much space they consume. Good for finding out space-hogs when tidying up disk space.
Intended for dynamic ip OpenDNS users, this command will update your OpenDNS network IP.
For getting your IP, you can use one of the many one-liners here on commandlinefu.
I use this in a script which is run by kppp after it has successfully connected to my ISP:
IP="`curl -s http://checkip.dyndns.org/ | grep -o '[[:digit:].]\+'`"
if [ "$IP" == "" ] ; then echo 'Not online.' ; exit 1
wget -q --user=topsecret --password="`echo $PW | xxd -ps -r`" 'https://updates.opendns.com/nic/update?hostname=myhostname&myip='"$IP" -O -
/etc/init.d/ntp-client restart &
PS: DynDNS should use a similar method, if you know the URL, please post a comment. (Something with members.dyndns.org, if I recall correctly)
Since bash 4.0, you can use ** to recursively expand to all files in the current directory. This behaviour is disabled by default, this command enables it (you'd best put it in your .profile). See the sample output for clarification.
In my opinion this is much better than creating hacks with find and xargs when you want to pass files to an application.
This is a (last resort) way to automate applications that provide no other ways for automation, it would send 'Hello world' to the currently active window. See the manpage (and the -text and -window entries) for how to send special characters and target specific windows.
Using xwininfo, I get the id of my XPlanet background window:
xwininfo: Please select the window about which you
would like information by clicking the
mouse in that window.
xwininfo: Window id: 0x3600001 "Xplanet 1.2.0"
Absolute upper-left X: 0
Now I use xvkbd to tell it to close itself:
xvkbd -xsendevent -window 0x3600001 -text "Q"
Obviously, the best way is to put these commands in a shellscript - just make sure to include a short sleep (sleep .1 should suffice) after each xvkbd call, or some programs will become confused.
I had a hard time in finding the correct settings to get reasonable output from a coin selector which sends its data over a serial line. In the end, minicom came to the rescue and pointed me on the right track.
So, if you need to do something similar, these settings may help you.
Replace ttyUSB0 with your device file, 9600 with your baud rate, 5 with your read timeout (10ths of a second), and 1 with the minimum numbers of characters you want to read.
You can then open the device file like you are used to do, example:
DATA="`xxd -ps -l 5 \"$DEV\"`"
This command will tell lynx to read keystrokes from the specified file - which can be used in a cronjob to auto-login on websites that give you points for logging in once a day *cough cough* (which is why I used -accept_all_cookies).
For creating your keystroke file, use:
lynx -cmd_log yourfile
Suppose you made a backup of your hard disk with dd:
dd if=/dev/sda of=/mnt/disk/backup.img
This command enables you to mount a partition from inside this image, so you can access your files directly.
Substitute PARTITION=1 with the number of the partition you want to mount (returned from sfdisk -d yourfile.img).
This is useful if you have a program which doesn't work well with multicore CPUs. With taskset you can set its CPU affinity to run on only one core.
I use this command to save RTSP video streams over night from one of our national TV stations, so I won't have to squeeze the data through my slow internet connection when I want to watch it the next day.
For ease of use, you might want to put this in a file:
mplayer -dumpstream -dumpfile "$FILE" -playlist "$1"