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Transfer a file to multiple hosts over ssh
You can push files to up to 32 servers at once assuming ssh keys are in place. Great tool, it is part of the pssh suite.

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" }

Find if $b is in $a in bash
Find if $b is in $a in bash

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

Basic sed usage with xargs to refactor a node.js depdendency

copy paste multiple binary files
Useful when you have multiple files or binary files that you need to transfer to a different host and scp or the like is unavailable. To unpack on the destination host copy paste output using the opposite order: openssl enc -d -base64 | gunzip | tar -x Terminate openssl input using ^d Note: gzip is outside of tar because using -z in tar produces lots of extra padding.

Quick command line math
expr will give you a quick way to do basic math from the CLI. Make sure you escape things like * and leave a space between operators and digits.

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"

Log your internet download speed
This will log your internet download speed. You can run $gnuplot -persist

Quickly find a count of how many times invalid users have attempted to access your system


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