Commands by paulera (13)

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Ensure that each machine that you log in to has its own history file
On systems where your home directory is shared across different machines, your bash history will be global, rather than being a separate history per machine. This setting in your .bashrc file will ensure that each machine has its own history file.

Every Nth line position # (AWK)
A better way to show the file lines 3n + 1

list ips with high number of connections

Leap year calculation

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" }

Easily find latex package documentation
If the pdf/dvi/etc documentation for a latex package is already part of your local texmf tree, then texdoc will find and display it for you. If the documentation is not available on your system, it will bring up the package's webpage at CTAN to help you investigate.

extract column from csv file
extracts the 5th column using the delimiter ','

Get a quick list of all user and group owners of files and dirs under the cwd.
find -printf '%u\n' | sort | uniq #just users find -printf '%g\n' | sort | uniq #just groups

check open ports (both ipv4 and ipv6)

Update your journal
prerequisite: $ mkdir ~/journal


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