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list files recursively by size

check open ports without netstat or lsof

Generate Random Passwords
If you want a password length longer than 6, changing the -c6 to read -c8 will give you 8 random characters instead of 6. To end up with a line-feed, use this with echo: # echo `< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6` Modern systems need higher strenght, so add some special characters: # < /dev/urandom tr -dc '12345!@#$%qwertQWERTasdfgASDFGzxcvbZXCVB' | head -c8

This command can be used to extract the IP address of the network.
can be used within a script to configure iptables for example: iface=$2 inet_ip=`ifconfig "$iface" | grep inet | cut -d: -f2 | cut -d ' ' -f1` ipt="sudo /sbin/iptables" ......................... ---------------------------------------------------------------------------------------------------------------- $ipt -A INPUT -i $iface ! -f -p tcp -s $UL -d $inet_ip --sport 1023: --dport 3306 -m state --state NEW,ESTABLISHED -j ACCEPT ---------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------- $ipt -A OUTPUT -o $iface -p tcp -s $inet_ip -d $UL --sport 3306 --dport 1023: -m state --state ESTABLISHED,RELATED -j ACCEPT -----------------------------------------------------------------------------------------------------------------

Get the Volume labels all bitlocker volumes had before being encrypted
Get information of volume labels of bitlocker volumes, even if they are encrypted and locked (no access to filesystem, no password provided). Note that the volume labels can have spaces, but only if you name then before encryption. Renaming a bitlocker partition after being encrypted does not have the same effect as doing it before.

ROT13 using the tr command

Quick key/value display within /proc or /sys
Within /proc and /sys there are a lot of subdirectories, which carry pseudofiles with only one value as content. Instead of cat-ing all single files (which takes quite a time) or do a "cat *" (which makes it hard to find the filename/content relation), just grep recursively for . or use "grep . /blabla/*" (star instead of -r flag). For better readability you might also want to pipe the output to "column -t -s : ".

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" }

Extract title from HTML files
This command can be used to extract the title defined in HTML pages

Generate binary sequence data


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