I am trying to understand info who
but completly fail at the term »non-option argument«. Can someone please explain this term to me in simple words or an example?
UPDATE: from ' info who' :
If given no non-option arguments, `who' prints the following information for each user currently logged on: login name, terminal line, login time, and remote hostname or X display.
If given one non-option argument,
who' uses that instead of a default system-maintained file (often
/var/run/utmp' or/etc/utmp') as the name of the file containing the record of users logged on.
/var/log/wtmp' is commonly given as an argument to `who' to look at who has previously logged on.If given two non-option arguments,
who' prints only the entry for the user running it (determined from its standard input), preceded by the hostname. Traditionally, the two arguments given are
am i', as in `who am i'.
I [thought to] know the difference between an argument and an option, but this [again] nixes a lot.
info
pages have probably done more damage to being able to learn UNIX. They are harder to use and navigate than man pages, and since they exist, most folks consider a real man page to be optional. So you end up with terrible documentation. This is part of what has made me love the BSDs, particular OpenBSD. The man pages are almost always good and useful. And if they are not, the developers consider it a bug. – kurtm Oct 20 '13 at 5:59