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Find common lines between two files

Bypass with hexencoding, dump /etc/passwd

Retrieve the size of a file on a server
Downloads the entire file, but http servers don't always provide the optional 'Content-Length:' header, and ftp/gopher/dict/etc servers don't provide a filesize header at all.

Video Google download
Download google video with wget. Or, if you wish, pass video URL to ie mplayer to view as stream. 1. VURL: replace with url. I.e. http://video.google.com/videoplay?docid=12312312312312313# 2. OUPUT_FILE : optionally change to a more suited name. This is the downloaded file. I.e. foo.flv # Improvements greatly appreciated. (close to my first linux command after ls -A :) ) Breakedown pipe by pipe: 1. wget: html from google, pass to stdout 2. grep: get the video url until thumbnailUrl (not needed) 3. grep: Strip off everything before http:// 4. sed: urldecode 5. echo: hex escapes 6. sed: stipr of tailing before thumbnailUrl 7. wget: download. Here one could use i.e. mplayer or other...

Search for a string inside all files in the current directory

'hpc' in the box - starts a maximum of n compute commands modulo n controlled in parallel
the block of the loop is useful whenever you have huge junks of similar jobs, e.g., convert high res images to thumbnails, and make usage out of all the SMP power on your compute box without flooding the system. note: c is used as counter and the random sleep $ r=`echo $RANDOM%5 |bc`; echo "sleep $r"; sleep $r is just used as a dummy command.

network throughput test
On the machine acting like a server, run: $ iperf -s On the machine acting like a client, run: $ iperf -c ip.add.re.ss where ip.add.re.ss is the ip or hostname of the server.

View non-printing characters with cat
Useful to detect number of tabs in an empty line, DOS newline (carriage return + newline). A tool that can help you understand why your parsing is not working.

Switch to a user with "nologin" shell
You need sudo privileges for this command. Replace username with actual username.

Erase CD RW


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