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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" }

Watch the progress of 'dd'
Running this code will execute dd in the background, and you'll grab the process ID with '$!' and assign it to the 'pid' variable. Now, you can watch the progress with the following: $ while true; do kill -USR1 $pid && sleep 1 && clear; done The important thing to grasp here isn't the filename or location of your input or output, or even the block size for that matter, but the fact that you can keep an eye on 'dd' as it's running to see where you are at during its execution.

Comma insertions
Insert a comma where necessary when counting large numbers. I needed to separate huge amounts of packets and after 12+ hours of looking in a terminal, I wanted it in readable form.

convert a line to a space

Convert camelCase to underscores (camel_case)
Useful for switching over someone else's coding style who uses camelCase notation to your style using all lowercase with underscores.

Release memory used by the Linux kernel on caches
The Linux kernel uses unused memory in caches. When you execute "free" you never get the "real" available memory.

Get the full path to a file
Useful in scripts when the file is passed in as an argument. Eg. $ filepath=$(realpath $1)

Blackhole any level zones via dnsmasq
Explanation It creates dnsmasq-com-blackhole.conf file with one line to route all domains of com zones to 0.0.0.0 You might use "address=/home.lab/127.0.0.1" to point allpossiblesubdomains.home.lab to your localhost or some other IP in a cloud.

copy partition table from /dev/sda to /dev/sdb

Convert JSON to YAML


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