Commands by defiantredpill (6)

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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Generate random valid mac addresses
Shorter and more straightforward. Also in perl: $ perl -e 'print join(":", map { sprintf "%0.2X",rand(256) }(1..6))."\n"'

Show a notify popup in Gnome that expires in specified time and does not leave an icon in notifications tray
Tested in Gnome 3.4

lines in file2 that are not in file1

Changing the terminal title to the last shell command
You can set the previous bash command as the terminal title by this command. Explanation: -trap assigns a command to execute at a given bash signal. -in the $BASH_COMMAND you find the last command -you can set the terminal title with the escape sequence: \e]0;this is the title\007 -to let the echo care about the backslashes give the -e to it Since trap is a built in bash command you find more informatin in 'man bash'for more Source:

prevents replace an existing file by mistake
Use set +o noclobber and you will be able to replace files again

find . -name

Create a bunch of dummy text files
Avoiding a for loop brought this time down to less than 3 seconds on my old machine. And just to be clear, 33554432 = 8192 * 4086.

diff files while disregarding indentation and trailing white space
**NOTE** Tekhne's alternative is much more succinct and its output conforms to the files actual contents rather than with white space removed My command on the other hand uses bash process substitution (and "Minimal" Perl), instead of files, to first remove leading and trailing white space from lines, before diff'ing the streams. Very useful when differences in indentation, such as in programming source code files, may be irrelevant

analyze traffic remotely over ssh w/ wireshark
Please check out my blog article on this for more detail.

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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