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Create a backup copy of a MySQL database on the same host
This should probably only be used for testing in a dev environment as it's not terribly efficient, but if you're doing something that might trash a DB and you still want the old data available, this works like a charm.

open two files on top of each other in vim (one window, two panes)

Find the package that installed a command

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

Determine an image's dimensions
Simple use of ImageMagick identify function.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Browse shared folder when you're the only Linux user
Under Ubuntu smbclient is part of the samba package. With the version I use (3.0.28a) cd-ing into folders with spaces in the name is a drag. You have to put the folder name in quotes: smb: \Shared\> cd "Marketing and PR"

Check if a machine is online
PING parameters c 1 limits to 1 pinging attempt q makes the command quiet (or silent mode) /dev/null 2>&1 is to remove the display && echo ONLINE is executed if previous command is successful (return value 0) || echo OFFLINE is executed otherwise (return value of 1 if unreachable or 2 if you're offline yourself). I personally use this command as an alias with a predefined machine name but there are at least 2 improvements that may be done. Asking for the machine name or IP Escaping the output so that it displays ONLINE in green and OFFLINE in red (for instance).

Get a facebook likes quantity from CLI
Replace the with your URL, for example http://rublacklist.net/12348/ and it will show likes number

send raw data (hex written)using UDP to an IP and port
Use it to send raw data to a networked device. Used to interact with relay controller board whose documentation is lost, so use wireshark to sniff the sent data and replayed using the command.


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