C considerations

C programs written to the external CICS® interface must provide their parameters on the CALL to DFHXCIS in the form of an assembler-style parameter list. You ensure this by declaring the entry point to DFHXCIS with OS LINKAGE.

The EXCI copybook for C, DFHXCPLH, contains the necessary definition of the DFHXCIS entry point, as follows:

  #pragma linkage(dfhxcis,OS)

The same rule applies for the EXCI LINK command, and in this case the CICS translator ensures that the correct parameter list is built.

For an example of an EXCI client program written in C, see the source of the sample program, DFH$DXCC.