Unix and linux are ____ systems, which allow one user to execute more than one program at a time.

Files in Unix may be a representation of the system's:

The notation '.' in an ls listing, is shorthand for:

When you type the name of a command, the shell finds it in:

The Unix end-of-file character is:

What do we get from running this command? echo 'april|may|june|july' | awk -F'|' '{print $3}'

Files in Unix may be a representation of the system's: