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Create a QR code image in MECARD format
Add the QR code image on your webpage, business card ., etc, so people can scan it and quick add to their Contact Address Book. Tested on iPhone with QRreader.

Convert JSON to YAML

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

Keep a copy of the raw Youtube FLV,MP4,etc stored in /tmp/
Certain Flash video players (e.g. Youtube) write their video streams to disk in /tmp/ , but the files are unlinked. i.e. the player creates the file and then immediately deletes the filename (unlinking files in this way makes it hard to find them, and/or ensures their cleanup if the browser or plugin should crash etc.) But as long as the flash plugin's process runs, a file descriptor remains in its /proc/ hierarchy, from which we (and the player) still have access to the file. The method above worked nicely for me when I had 50 tabs open with Youtube videos and didn't want to have to re-download them all with some tool.

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

Diff files over SSH
Sometimes you need to compare two config files on different servers. Put the file names into the above script and let 'er rip.

Recursively change permissions on files, leave directories alone.

Rip audio from a video file.
Replace and accordingly.

find all file larger than 500M

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


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