joe:tldr:0dbe9

The command "joe -rdonly ${filename}" is used to open a file named ${filename} in read-only mode using the text editor called "joe".

Here's a breakdown of each component of the command:

• "joe": Refers to the name of the text editor program, which is being invoked.
• "-rdonly": A flag or option that specifies the desired mode for opening the file. In this case, it stands for "read-only mode", meaning that the file can only be read but not modified or edited.
• "${filename}": A placeholder that represents the actual name of the file you want to open with joe in read-only mode. You need to replace "${filename}" with the specific name of the file (e.g., "document.txt") you wish to view.

Overall, this command allows you to open and view the contents of a file using the "joe" editor without the ability to make any modifications.