Commands by unixmonkey4581 (2)

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Remove security limitations from PDF documents using ghostscript (for Windows)
#4345 also works under windows

find an unused unprivileged TCP port
perl-less way

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" }

floating point operations in shell scripts
Calculator for shell. Similar performance and basic usage as 'bc', but with more advanced features. Not installed on most systems by default.

Unzip multiple files with one command
With this command you can easily unzip multiple zip files with just one command. All you need to do is to use single quotes.

Print a list of all hardlinks in the working directory, recursively
libpurple likes to hardlink files repeatedly. To ignore libpurple, use sed: | sed '/\.\/\.purple/d'

remove repeated pairs of characters e.g. "xtxtxtxt" will become "xt"
This will remove repeated characters e.g. echo "xtxtxtxt" | sed -ru 's/(..)\1{2,}/\1/g' the output will just be "xt"

Send a local file via email
Another way of sending an attachment. -s : subject file : file to be sent

diff current vi buffer edits against original file

Count items in JSON array
Pipe any JSON to jq, then count with the appropiate expression and use the | length on the array


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