-h prints quick usage.
-n prints any non-zero user namespace root user ID value found to be associated with a file's
capabilities.
-r enables recursive search.
-v display all searched entries, even if the have no file-capabilities.
NOTE: an empty value of '=' is not equivalent to an omitted (or removed) capability on a file. This is
most significant with respect to the Ambient capability vector, since a process with Ambient capabilities
will lose them when executing a file having '=' capabilities, but will retain the Ambient inheritance of
privilege when executing a file with an omitted file capability. This special empty setting can be used
to prevent a binary from executing with privilege. For some time, the kernel honored this suppression for
root executing the file, but the kernel developers decided after a number of years that this behavior was
unexpected for the superuser and reverted it just for that user identity. Suppression of root privilege,
for a process tree, is possible, using the capsh(1) --mode option.
filename
One file per line.