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Schedule a script or command in x num hours, silently run in the background even if logged out
doesn't require "at", change the "2h" to whatever you want... (deafult unit for sleep is seconds)

get xclip to own the clipboard contents
"Copying" things to the X clipboard doesn't normally create a copy. Rather the data to be 'copied' is referenced. This means that if the application that you 'copied' stuff from is closed, that data is lost. If the application that you 'copied' from is suspended with CTRL-Z, there could be some issues if you try to paste it into something. This command will create a copy of referenced data and have xclip be the provider of it, so you can then go ahead and close the app that contains the original information. Caveat: I'm not sure if this is binary-safe (though i would expect it to be), and don't know what would happen if you used it to clip a 20 meg gimp image. This technique becomes more convenient if you set it up as an action in a clipboard manager (eg klipper, parcellite). Some of these applets can take automatic action based on a variety of parameters, so you could probably just get it to always own the clipped data whenever data is clipped.

Extract ip addresses with sed
Extracts ip addressess from file using sed. Uses a tag(ip) to grep the IP lines after extracting. Must be a way to just output regex matched on sed.

fdiff is a 'filtered diff'. Given a text filter and two inputs, will run the filter across the input files and diff the output.
Fdiff will run the command given by the first argument against the input files given as the second and third arguments, and diff the results. It will use 'diff' as the default diff program, but this can be changed by setting $DIFFCMD, e.g. $ export DIFFCMD=vimdiff; $ fdiff zcat 0716_0020005.raw.gz 0716_0030005.raw.gz ... This function will work under bash, but requires the use of command substitution, which is not available under a strict ANSI shell.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

get useful statistics from tcpdump (sort by ip)
We can get useful statistics from tcpdump with this simple command. Thanks "Babak Farrokhi" to teaching me this ;)

function to compute what percentage of X is Y? Where percent/100 = X/Y => percent=100*X/Y
This function make it easy to compute X/Y as a percentage. The name "wpoxiy" is an acronym of "what percentage of X is Y"

analyze traffic remotely over ssh w/ wireshark
This captures traffic on a remote machine with tshark, sends the raw pcap data over the ssh link, and displays it in wireshark. Hitting ctrl+C will stop the capture and unfortunately close your wireshark window. This can be worked-around by passing -c # to tshark to only capture a certain # of packets, or redirecting the data through a named pipe rather than piping directly from ssh to wireshark. I recommend filtering as much as you can in the tshark command to conserve bandwidth. tshark can be replaced with tcpdump thusly: $ ssh root@example.com tcpdump -w - 'port !22' | wireshark -k -i -

Switch to a user with "nologin" shell
You need sudo privileges for this command. Replace username with actual username.

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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