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Count the number of queries to a MySQL 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" }

cat stdout of multiple commands
Concatenate the stdout of multiple commands.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Get an IP address out of fail2ban jail
Removes an iptables rule created by fail2ban. This example shows how to remove a rule for an IP from the fail2ban-SSH chain. Can be used for any service monitored by fail2ban. For more on fail2ban, see http://www.fail2ban.org/wiki/index.php/Main_Page

See system users

Place the argument of the most recent command on the shell
This works if your terminal is in Vi mode

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

poor man's vpn
this easy to install tool redirects all traffic to internet through ssh. it's very usefull when connecting to free wifi. you need to start it as root because it needs permissions to change iptables settings. ofcourse you also need a shell account

which program is this port belongs to ?
Sometimes you need to use a port that is already opened by some program , and you don't know who to "kill" for it to release - so, now you do !


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