Commands by dynaguy (6)

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Backup your hard drive with dd
This will create an exact duplicate image of your hard drive that you can then restore by simply reversing the "if" & "of" locations. $ sudo dd if=/media/disk/backup/sda.backup of=/dev/sda Alternatively, you can use an SSH connection to do your backups: $dd if=/dev/sda | ssh dd of=~/backup/sda.backup

Remove newlines from output
Pipe any output to "grep ." and blank lines will not be printed.

Mac osx friendly version of this terminal typing command at 200ms per key

Losslessly rotate videos from your phone by 90 degrees.
Takes all the .3gp files in the directory, rotates them by 90 degrees, and saves them in the lossless ffv1 encoding. If this rotates in the wrong direction, you may want transponse=1 Re-encoding to ffv1 may result in a significant increase in file size, as it is a lossless format. Other applications may not recognize ffv1 if they don't use ffmpeg code. "huffyuv" might be another option for lossless saving of your transformations. The audio may be re-encoded as well, if the encoding used by your 3gp file doesn't work in a avi container.

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

Create QR codes from a URL.
QR codes are those funny square 2d bar codes that everyone seems to be pointing their smart phones at. Try the following... $ qrurl Then open qr.*.png in your favorite image viewer. Point your the bar code reader on your smart phone at the code, and you'll shortly be reading xkcd on your phone. URLs are not the only thing that can be encoded by QR codes... short texts (to around 2K) can be encoded this way, although this function doesn't do any URL encoding, so unless you want to do that by hand it won't be useful for that.

set your ssd disk as a non-rotating medium
if you still get a permissions error using sudo, then nano the file: sudo nano -w /sys/block/sdb/queue/rotational and change 1 to 0 this thread: says that this will "help the block layer to optimize a few decisions"

Insert a colon between every two digits
I sometimes have large files of MAC addresses stored in a file, some databases need the information stored with the semicolon (makes for easier programming a device) others don't. I have a barcode to text file scanner which usually butchers MAC addresses so this was the fix> I initially did this in awk ;) awk '{for(i=10;i>=2;i-=2)$0=substr($0,1,i)":"substr($0,i+1);print}' mac_address_list

Play random music from

show the date every rpm was installed
the newest rpms are at the top; individual packages can also be queried this way: rpm --last -q package

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