Commands using su (17)

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Install pip with Proxy
Installs pip packages defining a proxy

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"

Compute running average for a column of numbers
This is an on-line algorithm for calculating the mean value for numbers in a column. Also known as "running average" or "moving average".

Random unsigned integer
Reads 4 bytes from the random device and formats them as unsigned integer between 0 and 2^32-1.

find all active IP addresses in a network
There are several other options. This one is plain and simple. Another option is: nmap -sP 192.168.0.0/24

Search for a word in less
Although less behaves more or less like vim in certain aspects, the vim regex for word boundaries (\< and \>) do not work in less. Instead, use \b to denote a word boundary. Therefore, if you want to search for, say, the word "exit", but do not want to search for exiting, exits, etc., then surround "exit" with \b. This is useful if you need to search for specific occurrences of a keyword or command. \b can also be used at just the beginning and end, if needed.

remove empty lines in place with backup
Modify file in place to remove empty lines and create a backup of the original with the extension .bak

Copy a file to a new directory created on the fly
You need to cp, mv, scp, ..., some files around from one place to another, and after having laboriously typed out the source path, you remember that the destination directory doesn't yet exist, and so the command will fail. So rather than killing the command line and starting over, just interpolate the results of creating the directory and echo its name. You could DRY this with a for; do; done, but that may be more trouble than it's worth.

Burn an ISO on the command line.

make, or run a script, everytime a file in a directory is modified


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