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FizzBuzz one-liner in Python
A common programming question for interviewers to ask potential job candidates is to code "FizzBuzz". That is, if a number is divisible by 3, then it should display "Fizz". If a number is divisible by 5, it should display "Buzz". If it is divisible by both, then it should display "FizzBuzz". Otherwise, display the current number between 1 and 100.

Search apache virtual host by pattern
Outputs contents of virtual hosts containing PATTERN. Particularly useful for pefrorming complex searches. E.g. search for docroot of www.example.com: $ sed -n '/^[^#]*

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

cp the file
Copy the file with the given .extension at the source file's location. Eliminates the typing of long paths again and again.

sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)
POSIX requires this "string truncating" functionality. might as well use it, at least for very small tasks where invoking sed and using RE is overkill.

DVD ripping with ffmpeg
To rip DVD movie to ogg format using ffmpeg, follow these steps. 1) find the vob files on the mounted video DVD in VIDEO_TS that stores the movie itself. There would be a few other VOB files that stores splash screen or special features, the vob files for the movie itself can be identified by its superior size. You can verify these vob files by playing them directly with a player (e.g. mplayer) 2) concatenate all such vob files, pipe to ffmpeg 3) calculate the video size and crop size. The ogg video size must be multiple of 16 on both width and height, this is inherit limitation of theora codec. In my case I took 512x384. The -vcodec parameter is necessary because ffmpeg doesn't support theora by itself. -acodec is necessary otherwise ffmpeg uses flac by default.

Configure a serial line device so you can evaluate it with a shell script
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\"`"

Find chronological errors or bad timestamps in a Subversion repository
Lists revisions in a Subversion repository with a timestamp that doesn't follow the revision numbering order. If everything is OK, nothing is displayed.

convert a mp4 video file to mp3 audio file (multiple files)

Debug a remote php application (behind firewall) using ssh tunnel for XDEBUG port 9000
If you need to xdebug a remote php application, which is behind a firewall, and you have an ssh daemon running on that machine. you can redirect port 9000 on that machine over to your local machine from which you run your xdebug client (I am using phpStorm) So, run this command on your local machine and start your local xdebug client, to start debugging. more info: http://code.google.com/p/spectator/wiki/Installing


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