Per man definition, this command gets the input from a file.
$ command -r FILENAME
FILENAME is a file containing a list of filenames, as it was generated using
ls > FILENAME.
How can I, instead, feed the command with the result of
ls directly? In my head something like this should be possible:
$ ls | command -r
But it doesn't, the output of
ls doesn't get hooked as an argument. Output:
Usage: command -r FILENAME error: -r option requires an argument
How could I obtain the desired effect?