xz:tldr:85e80

The command "xz -9 ${filename}" is used to compress a file using the xz compression algorithm with the highest compression level. Here is an explanation of the components:

• "xz": This is the command-line utility for compressing and decompressing files using the xz algorithm.
• "-9": This is an option provided by the xz command to indicate the compression level. In this case, the number 9 represents the highest compression level, resulting in the smallest possible compressed file size.
• "${filename}": This is a placeholder that should be replaced with the actual name of the file you want to compress. The curly braces and the dollar sign are used to reference a variable (in this case, "filename") from the environment or command line arguments.

In summary, running the "xz -9 ${filename}" command will compress the specified file using the xz algorithm and the highest compression level. The original file will be replaced with a compressed file with the ".xz" extension.