troff:tldr:2fa85

The given command is using the troff typesetting system to format a document and display it on the terminal using a text-based output device.

Here is a breakdown of each part of the command:

1. troff is the command used to invoke the troff typesetting system.
2. -T ${ascii} specifies the output device or terminal type. In this case, ${ascii} is a variable representing the ASCII text output mode, which means the output will be plain text.
3. -${man} specifies the desired format for the output. ${man} is a variable representing the "man" format, which is commonly used for Unix manual pages.
4. ${path-to-input-roff} is the path to the input file that needs to be processed and formatted by troff. This file should be written in the roff language, which is a markup language used for typesetting documents.
5. | is a pipe symbol that connects the output of the previous command to the input of the next command.
6. grotty is a command that processes the troff output and converts it into a format suitable for display on a terminal. It handles various formatting features, such as line wrapping, page breaks, and character rendering.

Overall, the command takes an input file written in the roff language, formats it using troff with the specified output and format options, and then passes the formatted output to grotty for display on the terminal in a readable manner.