base64:tldr:cb892

This command involves two parts, separated by the pipe symbol (|).

1. echo -n ${base64_text}: This command is used to print the value of the variable base64_text on the standard output. The -n option is used to prevent the trailing newline character from being added to the output.

2. base64 --decode: This command takes the base64-encoded input from echo and decodes it back to its original form. The --decode option tells the base64 utility to perform decoding instead of encoding.

In summary, this command takes a base64-encoded string stored in the variable base64_text, prints it to the standard output, and then uses the base64 utility to decode it, returning the original text.