Ad 1)
It is safe (within reason, that is) .... halt will first
"politely ask" all process to terminate themselves,
than send them a SIGKILL after a while, and then
shut the system down ... if you happen to have an
unsaved file in an editor it won't ask you to save
them, though ...
Ad 2)
ls -al *c
Ad 3)
man pwd
Code:
--help display this help and exit
--version
output version information and exit
Cheers,
Tink