GNAT Reference Manual
9.28 GNAT.Expect (g-expect.ads)
Provides a set of subprograms similar to what is available
with the standard Tcl Expect tool.
It allows you to easily spawn and communicate with an external process.
You can send commands or inputs to the process, and compare the output
with some expected regular expression.
Currently GNAT.Expect is implemented on all native GNAT ports except for
OpenVMS. It is not implemented for cross ports, and in particular is not
implemented for VxWorks or LynxOS.