which -- locate a program file in the user's path
which [-as] program ...
The which utility takes a list of command names and searches the path for each executable file that would be run had these commands actually been invoked.
Some shells may provide a builtin which command which is similar or identical to this utility.
- -a
- List all instances of executables found (instead of just the first one of each).
- -s
- No output, just return 0 if any of the executables are found, or 1 if none are found.
which - shows the full path of (shell) commands
which java