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SMTP Analysis
This works just as well for SMTP. You could run this on your mail server to watch e-mail senders and recipients: tcpdump -l -s0 -w - tcp dst port 25 | strings | grep -i 'MAIL FROM\|RCPT TO'

Minimize active window
Bind it to some shortcut key, using something like xbindkeys-config (if you do not have xbindkeys: apt-get install xbindkeys xbindkeys-config)

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"

Output Detailed Process Tree for any User
An easy function to get a process tree listing (very detailed) for all the processes of any gived user. This function is also in my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Run a command when a file is changed

Install pip with Proxy
Installs pip packages defining a proxy

Execute a command with a timeout
In this example the command "somecommand" will be executed and sent a SIGALARM signal if it runs for more than 10 seconds. It uses the perl alarm function. It's not 100% accurate on timing, but close enough. I found this really useful when executing scripts and commands that I knew might hang E.g. ones that connect to services that might not be running. Importantly this can be used within a sequential script. The command will not release control until either the command completes or the timeout is hit.

List files by quoting or escaping special characters.
Tested and works on Linux.

Count number of files in a directory
Just want to post a Perl alternative. Does not count hidden files ('.' ones).

Print macOS current power delivery max wattage
Print the max wattage of the current power draw source for a Mac. Note that the current amount of watts drawn may be lower, particularly if a high-wattage adapter is plugged into a Mac that has a full battery.


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