-vn removes tha video content, the copy option tells ffmpeg to use the same codec for generating the output

The quality ranges between 0 to 9, with the smaller number indicates a higher quality file but bigger too.

Using mplayer to extract audio file from a CD

It can be hard to spot differences in reformatted files, because of all the diff noise created by word wrapped lines. This command removes all the noise and performs a word-by-word diff. To ignore empty lines, add -B to the diff command. Also, if this is something you do often, you might want to check out the wdiff(1) program.

This command will let you just type c-a b (which means press 'ctrl' then 'a' then 'b'), and screen will save your copy buffer to /tmp/screen-exchange, and then execute xsel to copy the contents of that file into the system's X clipboard.

1. Install Conrad Parker's xsel from http://www.vergenet.net/~conrad/software/xsel/

2. Add these lines to your .screenrc

# Add cool line to make copying to x clipboard possible.

# This binds C-a b to copy screen's copy buffer to the system clipboard.

bind b eval writebuf 'exec /bin/sh -c "xsel -i -b < /tmp/screen-exchange"' 'exec /bin/sh -c "killall xsel"'

3. Restart screen.

4. Test it by typing c-a [ to enter copy mode.

5. Select some text using vi movement keys (h, j, k, l, etc...) and starting your selection by hitting the space bar, moving with vi movement keys, and then ending your selection with the space bar.

6. Type C-a b, and screen will use xsel to copy your screen copy buffer to the system's X clipboard buffer.

7. Then you can paste the screen copy buffer into any X program.

Note: If you're using Mac OSX, you can use pbcopy instead of xsel.

Also Note: The second exec in the .screenrc file, which runs killall on xsel, is necessary, because even when you redirect a file to xsel, xsel waits for you to press ctrl-c to kill it, and have it stop waiting for more input. Since xsel forces screen to wait, and I don't want to press ctrl-c, I send the equivalent of ctrl-c with killall causing xsel to write /tmp/screen-exchange to the X clipboard, and then exit. It's a hack, but it works. If you know how to get this to work without a lame hack leave a comment explaining how.

will display typedefs, structs, unions and functions declared in 'stdio.h'(checkout _IO_FILE structure). It will be helpful if we want to know what a particular header file will offer to us. Command 'cpp' is GNU's C Preprocessor.

This is useful for use in scripts.

Note that this will leak your password to ps, so this shouldn't be used on shared machines. Use key files for this

you have to replace "mustek_usb" with the scanner found by `scanimage -l`

Useful if you have to put some mp3 files into mobile devices (ie mobile phones with no much memory)

This is useful for command line 'recycle bins' and such like

Taken from - http://maven.apache.org/guides/mini/guide-ide-eclipse.html

This will update the tarball, adding files that have changed since the last update.

This assumes that the tarball is in the same directory as the files being archived.

N.B. This command can't be used on compressed tarballs.

N.B. This will add the updated files to the tarball, so that the tarball will have two versions of each file. This will make the tarball larger, but doesn't have any other significant effect.

If you're addicted to command-line solutions of ordinary actions or if you just want to set your volume from bed via mobile phone SSH, you can set this alias and use it as

for setting volume on 50% gain

Works only with ALSA, tested on Ubuntu 8.10. Give me some info about your experience.

TIP: Try aslo command "mute" to toggle mute/unmute sound. But I don't know if this works on all distros.

With this you can unlock your KDE4 session via SSH, via mobile phone SSH or e. g. scheduled task in crontab (without asking password). Useful when you need to grant somebody access to your locked profile remotely.

Create an alias (e. g. as "unlock") and use with remote KDE4 lock.

This works only on KDE4 boxes because KDE 3 is using utility with another name.

Tested on Kubuntu 8.10.

Forgot to lock your computer? Want to lock it via SSH or mobile phone or use it for scheduled lock?

TIP: Make a alias for this (e. g. as "lock").

I found some howtos for ugly X11 lock, but this will use regular KDE locking utility.

Note that KDE 3 is using utility with another name (I guess with the same argument --forcelock)

Tested on Kubuntu 8.10.

Stay tuned for remote unlock.

Tuned for short command line - you can set the path to sessionstore.js more reliable instead of use asterixes etc.

Usable when you are not at home and really need to get your actual opened tabs on your home computer (via SSH). I am using it from my work if I forgot to bookmark some new interesting webpage, which I have visited at home. Also other way to list tabs when your firefox has crashed (restoring of tabs doesn't work always).

This script includes also tabs which has been closed short time before.

You need python-scapy package

Run GUI apps on another machine remotely through SSH.

-C is for data compression and -X enables X11 forwarding.

The curl command retrieve the HTML text containing the IP address. The grep command picks out the IP address from that HTML text.

This is one way to find out.

This is a simple command for jumping to the matching brace, square bracket, or parentheses. For example, it can take you from the beginning of a function to the end with one key stroke. To delete everything between the pairs of {}, [], or (), issue the command:

To replace text between pairs of braces, brackets, or parentheses, issue the command:

You can also use this command to find out if an opening brace has been properly closed.