source - read and execute commands from a file in the current shell environment.
source file [argument ...]
source reads and executes commands from file in the current shell environment. It is a compatibility alias for the POSIX . builtin. When file contains no slash, Rush searches PATH.
Additional operands initialize the positional parameters seen by the sourced script.
The status of the sourced script, one when the file cannot be opened, or two when the file operand is missing, cannot be found, or contains a syntax error.