Commands by curiousstranger (3)

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Get info about remote host ports and OS detection
Where < target > may be a single IP, a hostname or a subnet -sS TCP SYN scanning (also known as half-open, or stealth scanning) -P0 option allows you to switch off ICMP pings. -sV option enables version detection -O flag attempt to identify the remote operating system Other option: -A option enables both OS fingerprinting and version detection -v use -v twice for more verbosity. $ nmap -sS -P0 -A -v < target >

finding cr-lf files aka dos files with ^M characters
Looking for carriage returns would also identify files with legacy mac line endings. To fix both types: $ perl -i -pe 's/\r\n?/\n/g' $(find . -type f -exec fgrep -l $'\r' "{}" \;)

bash auto-complete your screen sessions
this bash command sets it so that when you type "screen ", it searches your running screens, and present valid auto-complete choices. The output is . Note: You must have programmable completion enabled. Check with "shopt progcomp", set with "shopt -s progcomp"

Convert JSON to YAML
Requires installing json2yaml via npm: npm install -g json2yaml (can also pipe from stdin) Ref: https://www.npmjs.com/package/json2yaml

list block devices
Shows all block devices in a tree with descruptions of what they are.

du disk top 10
fancy command line ncdu clone

python smtp server
This command will start a simple SMTP server listening on port 1025 of localhost. This server simply prints to standard output all email headers and the email body.

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"

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.

Remux an avi video if it won't play easily on your media device
When playback of AVI files (containing a video format like XviD or DivX) is stuttering, it in 90% of the files is caused by a poorly or wrongly interleaved file. The issue can be permanently resolved by RE-MUXING the AVI video-files that have this problem

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