To gather metrics from the UNIX command line, we can use the unannounced shell integration.
This integration has not yet been merged into the master branch so you will need to install this check as a custom check in the appropriate Datadog agent directories.
You can find the integration files on GitHub:
This solution is a good alternative to creating a custom check for data you can easily gather directly from the UNIX shell. For example, sending a metric with a value of the number of files in a certain directory.
The user that the agent runs as may need sudo access for the shell command. Sudo access is not required when running the agent as root (not recommended).