rich:tldr:38de4

The command you provided is likely a snippet from a shell script or command line interface. Let's break it down:

1. rich: It is the name of a command or executable being run. It refers to the "rich" tool, which is a Python library and command-line tool used for rich text and styling in terminal output.

2. ${filename-py}: This is a parameter or variable being passed to the rich command. The notation ${} is often used in shell scripting to refer to variables. In this case, filename is the name of the variable, and py is the default value if the variable is not set. So, it can be interpreted as replacing ${filename-py} with the value of the filename variable if it is set, or with "py" if it is not set.

3. --line-number: This is a flag or option being provided to the rich command. It instructs the tool to display line numbers alongside the text or code being formatted.

4. --guides: Another flag or option for the rich command. This flag tells the tool to display visual guides or markers in the formatted output, which can be helpful for code readability.

Overall, the command intends to format and style the contents of a file, specified by the filename variable, in a terminal using the rich tool. It will display line numbers alongside the text and include visual guides for improved readability.