idnits:tldr:a44e6

The command "idnits --year ${2021} ${filename-txt}" involves using the "idnits" command with specific parameters.

Here's what each part of the command represents:

• "idnits": It is the name of a tool or command-line program.
• "--year": It is an option or flag provided to the "idnits" command. In this case, it takes the argument "${2021}", which represents the year 2021. This option is usually used to specify the year or version for various checks or validations.
• "${filename-txt}": It is another argument provided to the "idnits" command. This argument should be replaced with the actual name of a file you want to process or analyze. The "${filename-txt}" format suggests that the file name should end with ".txt" extension. The command will use this file as input for further operations.

By running this command, you are instructing the "idnits" tool to perform its functions, potentially including checking or analyzing the specified file with the provided year as a parameter. The exact behavior and purpose of the "idnits" tool may depend on the context or the specific software or script it is associated with.