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Quickly find a count of how many times invalid users have attempted to access your system

View all new log messages in real time with color
This will show all changes in all log files under /var/log/ that are regular files and don't end with `gz` nor with a number

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"

Retrieve a random command from the commandlinefu.com API
Seeing that we get back plain text anyway we don't need lynx. Also the sed-part removes the credit line.

urlencoding with one pure BASH builtin
opposite of https://www.commandlinefu.com/commands/view/10014/urldecoding-with-one-pure-bash-builtin ;-)

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

Duplicate several drives concurrently
If you have some drive imaging to do, you can boot into any liveCD and use a commodity machine. The drives will be written in parallel. To improve efficiency, specify a larger block size in dd: $dd if=/dev/sda bs=64k | tee >(dd of=/dev/sdb bs=64k) | dd of=/dev/sdc bs=64k To image more drives , insert them as additional arguments to tee: $dd if=/dev/sda | tee >(dd of=/dev/sdb) >(dd of=/dev/sdc) >(dd of=/dev/sdd) | dd of=/dev/sde

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" }

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

Do some learning...
I like it sorted... 2> /dev/null was also needless, since our pipes already select stdin, only.


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