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Simplest port scanner
Very handy way to perform a host scan if you don't have nmap,ncat,nc ...or other tools installed locally. When executing a command on a /dev/tcp/$host/$port pseudo-device file, Bash opens a TCP connection to the associated socket and UDP connection when using /dev/udp/$host/$port.A simlpe way to get servers banner is to run this command "cat < /dev/tcp/localhost/25" , here you will get mail server's banner. NOTE: Bash, as packaged for Debian, does not support using the /dev/tcp and /dev/udp pseudo-device it's not enabled by default Because bash in Debian is compiled with ?disable-net-redirections.

Show the power of the home row on the Dvorak Keyboard layout
Quick and dirty command that counts how many words can be typed just using the home row on the Dvorak Simplified Keyboard layout from a dictionary file, in this case /usr/share/dict/words. According to the regular expression supplied, each word must contain all the keys on the Dvorak home row, and no other characters. For comparison, I've shown how many words are installed in my dictionary, how many can be typed with just the Dvorak home row and how many can be typed with just the QWERTY home row in the sample output. Nearly 10 times the amount. If you want to see the words, remove the -c switch, and each word will be printed out.

Advanced python tracing
Trace python statement execution and syscalls invoked during that simultaneously

a function to find the fastest DNS server
http://public-dns.info gives a list of online dns servers. you need to change the country in url (br in this url) with your country code. this command need some time to ping all IP in list.

Indent a one-liner.
I often write a one-liner which I want to use later in a script.

List open TCP/UDP ports

find text in a file
this will find text in the directory you specify and give you line where it appears.

Remove comments and empty lines from a conf file
Some conf file are very long (squid.conf) This command help to read it.

Using a single sudo to run multiple && arguments
This will also work with bash instead of sh shell sudo bash -c 'apt update -y && apt upgrade -y'

fix flash video (flv) file (ffmpeg)
Rebuild flv files that are broken (can't seek). This method probably works for other video/audio formats that can become broken in the same way.


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