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Convert spaces in file names to underscores

Quick notepad
Quick write some notes to a file with cat. Ctrl+C when you have finish.

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

Scan for [samba|lanman] NetBIOS names and ip addresses in LAN by ARP.

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"

FizzBuzz one-liner in Python
A common programming question for interviewers to ask potential job candidates is to code "FizzBuzz". That is, if a number is divisible by 3, then it should display "Fizz". If a number is divisible by 5, it should display "Buzz". If it is divisible by both, then it should display "FizzBuzz". Otherwise, display the current number between 1 and 100.

adjust laptop display hardware brightness [non root]

Watching Command
If you need to keep an eye on a command whose output is changing, use the watch command. For example, to keep an eye on your load average

FizzBuzz in one line of Bash
The (in)famous "FizzBuzz" programming challenge, answered in a single line of Bash code. The "|column" part at the end merely formats the output a bit, so if "column" is not installed on your machine you can simply omit that part. Without "|column", the solution only uses 75 characters. The version below is expanded to multiple lines, with comments added. for i in {1..100} # Use i to loop from "1" to "100", inclusive. do ((i % 3)) && # If i is not divisible by 3... x= || # ...blank out x (yes, "x= " does that). Otherwise,... x=Fizz # ...set x to the string "Fizz". ((i % 5)) || # If i is not divisible by 5, skip (there's no "&&")... x+=Buzz # ...Otherwise, append (not set) the string "Buzz" to x. echo ${x:-$i} # Print x unless it is blanked out. Otherwise, print i. done | column # Wrap output into columns (not part of the test).

Show directories in the PATH, one per line
The output of "echo $PATH" is hard to read, this is much easier. The parentheses ensure that the change to the input field separator (IFS) only happens the the sub shell and not affecting the current shell.


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