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Slow down IO heavy process
Some IO intensive process make the system unresponsive. This function periodically starts/stops a process, which hopefully releases some resources for other activities. This function is useful when ionice is not available

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

The BOFH Excuse Server

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" }

Merge various PDF files

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"

Substitute an already running command
eg: Already running cmd $sleep 120 Substitution cmd $c=$(pgrep sleep) && sleep 5 && kill $c

Labyrinth pattern
Generates labyrinth-like pattern on UTF-8 terminal in bash. For fun ;)

Multi-thread any command
For instance: $ find . -type f -name '*.wav' -print0 |xargs -0 -P 3 -n 1 flac -V8 will encode all .wav files into FLAC in parallel. Explanation of xargs flags: -P [max-procs]: Max number of invocations to run at once. Set to 0 to run all at once [potentially dangerous re: excessive RAM usage]. -n [max-args]: Max number of arguments from the list to send to each invocation. -0: Stdin is a null-terminated list. I use xargs to build parallel-processing frameworks into my scripts like the one here: http://pastebin.com/1GvcifYa

Start dd and show progress every X seconds
Adjust "sleep X" to your needs. *NOTE: First sleep is required because bash doesn't have a "post-test" syntax (do XXX while).


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