Remember the full pathnames of commands specified as name arguments, so they need not be searched for on subsequent invocations.
Syntax hash [-r] [-p filename] [name] Options -r Reset, causes the shell to forget all remembered locations. -p Use filename as the location of name (don't search $PATH).
The commands are found by searching through the directories listed in $PATH.
If no arguments are given, information about remembered commands is printed.
The return status is zero unless a name is not found or an invalid option is supplied.
This is a BASH shell builtin, to display your local syntax from the bash prompt type: help hash
"I spent most of the eighties, most of my life, riding around in somebody else's car, in possession of, or ingested of, something illegal, on my way from something illegal to something illegal with many illegal things happening all around me" ~ Iggy Pop
dirname - Convert a full pathname to just a path.
which - Show full path of commands.
Equivalent Windows command: SET - Display, set, or remove Windows environment variables.