Some binaries in Unix-Linux systems like ping or mount have a long argument. For example if we write ping -h
in the terminal, one of the options is:
Usage: ping [-aAbBdDfhLnOqrRUvV64]
Is this long set of characters really an argument?
Some binaries in Unix-Linux systems like ping or mount have a long argument. For example if we write ping -h
in the terminal, one of the options is:
Usage: ping [-aAbBdDfhLnOqrRUvV64]
Is this long set of characters really an argument?
No, this is an abbreviated way of listing all the possible single-letter options: -a
, -A
, -b
, etc. See the ping
manpage for details (for better results, run man ping
on your own system — that will show the documentation for the version you have installed).
-4
and -6
in this case.
– Nonny Moose
Jul 02 '18 at 01:37
... [-abc] any or all arguments within [ ] are optional."
– muru Jul 01 '18 at 22:47-abc
means here. The brackets make things optional, but there's still a difference between a literal string, a concatenation of multiple optional switches, and a string that's actually a description of some value. – ilkkachu Jul 02 '18 at 05:26man ping
! – peterh Jul 02 '18 at 08:29