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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"

Get duration of an audio file in seconds.
This is an alternative to #9131. ffmpeg didn't work on my .au files, though it did on the .wav ones. Also useful if you don't have ffmpeg but do have sox. Handily, sox already reports in seconds (decimal).

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

tail: watch a filelog
-f file(s) to be monitorized -n number of last line to be printed on the screen in this example, the content of two files are displayed

Validating a file with checksum

Ensure that each machine that you log in to has its own history file
On systems where your home directory is shared across different machines, your bash history will be global, rather than being a separate history per machine. This setting in your .bashrc file will ensure that each machine has its own history file.

Print all /etc/passwd lines with duplicated uid
Prints all the lines in /etc/passwd belonging to users with a duplicated uid. It also adds the hostname to the beginning of the line. It's been tested in AIX, Solaris and Linux.

Create a backup copy of a MySQL database on the same host
This should probably only be used for testing in a dev environment as it's not terribly efficient, but if you're doing something that might trash a DB and you still want the old data available, this works like a charm.

Install pip with Proxy
Installs pip packages defining a proxy

Get information about libraries currently installed on a system.
This command is very helpful when we need to duplicate a test scenario and first we want to find out the installed libraries together with the version and release numbers and architecture. (look example) Command can be tuned by choosing just the names of libraries we are interested in. For example glibc and gcc.


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