sort:tldr:c260b

The command sort --reverse ${filename} is used to sort the contents of the file specified by ${filename} in reverse order.

Here is a breakdown of the command:

• sort: This is the command used to sort lines of text alphabetically or numerically. It takes input from a file or standard input and outputs the sorted result.
• --reverse: This is an option provided by the sort command to sort the input in reverse order, which means the lines will be sorted in descending order instead of ascending.
• ${filename}: This is a placeholder for the actual filename that needs to be provided as an argument to the command. It could be the absolute or relative path of the file.

By executing the command, the contents of the specified file will be sorted in reverse order, and the result will be printed to the standard output or saved into a file depending on how the command is used.