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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" }

Create new user with home dir and given password
The crypt function takes a password, key, as a string, and a salt character array which is described below, and returns a printable ASCII string which starts with another salt. It is believed that, given the output of the function, the best way to find a key that will produce that output is to guess values of key until the original value of key is found. from http://en.wikipedia.org/wiki/Crypt_(Unix)

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"

Load your [git-controlled] working files into the vi arglist.
Branch name may be substituted, of course.

Find brute force attempts on SSHd
Searches the /var/log/secure log file for Failed and/or invalid user log in attempts.

Remove all unused kernels with apt-get
TIMTOWTDI

Protect your eye
Redshift will adjust the color temperature and protects eye at night -b : will adjust the brightness

count how many cat processes are running
'ps ax' provides the fill list of running processes. 'grep -c [c]at' will find all processes that match 'cat' without matching itself....

Generate random IP addresses
It never ends

Count the number of man pages per first character (a-z)
There once was a day I needed this info.


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