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Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Export a subset of a database
Limits the number of rows per table to X

convert mp3 into mb4 (audiobook format)
to convert a whole directory, put all mp3 files in a for loop $ for i in $(ls *mp3); do mpg123 -s $i | faac -b 80 -P -X -w -o ${i%mp3}m4b -; done

Create the signature base string required for a Twitter stream feed
This is the SECOND command in a set for five that are needed for a Twitter stream feed. This command creates variable "b", the so-called "base string" required for oauth in Twitter stream feed requests. (The 256 char limit prevents giving it a better name) We use five environment variables created by a previous step: id, k1, once, ts and k3. The five environment variables are created in a separate command, please see my other commands. For more information on the signature base string, see dev.twitter.com/apps, click on any app (or create a new one) and then go to the "OAuth Tool" tab.

Get the canonical, absolute path given a relative and/or noncanonical path
readlink -f accepts a relative, noncanonical path and emits the corresponding canonical, absolute path.

Identify differences between directories (possibly on different servers)
This can be much faster than downloading one or both trees to a common servers and comparing the files there. After, only those files could be copied down for deeper comparison if needed.

ssh autocomplete
Add to your bash profile to minimize carpal tunnel syndrome. Doesn't work with user@hostname but appending "-l user" works fine if needed. Works for ping as well.. complete -W "$(echo `cat ~/.ssh/known_hosts | cut -f 1 -d ' ' | sed -e s/,.*//g | uniq | grep -v "\["`;)" ping

Prevent non-root users from logging in
Also with optional message: $ echo "no login for you" > /etc/nologin (This doesn't affect your current X session - you're already logged in!)

list block devices
Shows all block devices in a tree with descruptions of what they are.

Open a file explorer on a split screen inside your vim session
Open a CLI file explorer by splitting up your screen inside your vim session. Besides, you probably are never going to forget this one.


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