IRXHST is a programming routine that searches for and runs a host command. IRXHST allows a compiler runtime processor to pass control to a host command through a direct interface. A compiler runtime processor that uses IRXHST leaves the implementation of the host command search and invocation to TSO/E REXX. For more information on the search order for host commands, refer to .

IRXHST also allows a compiler runtime processor to set and clear the ETMODE flag, based on the OPTIONS ETMODE or OPTIONS NOETMODE instructions. The ETMODE function of IRXHST sets the ETMODE flag, and the NOETMODE function of IRXHST clears the ETMODE flag. For more information about OPTIONS ETMODE and OPTIONS NOETMODE, see .