Problem:

What method for adding features to RM/COBOL was used prior to version 7.1?

Resolution:

Beginning with version 7.1 of RM/COBOL for UNIX, the customiz/relinking method for adding features to RM/COBOL was replaced with a simpler, more flexible system using optional support modules.  It is no longer necessary or possible to relink the runtime system, the compiler, or the recovery utility.  The customiz Bourne Shell script that was available in previous versions of RM/COBOL is no longer available.

UNIX versions of RM/COBOL prior to 7.1 allowed non-COBOL subprogram libraries to be linked into the runtime by modifying the source file sub.c and using a Makefile generated by the customiz script.  The source file sub.c is no longer present on the distribution media for UNIX.  However, the source file usrsub.c and the various header files that it needs (all present on the RM/COBOL for UNIX distribution media and in the installation directory) provide a starting point for an application designer to build an application-specific support module.  All of the special entry points for support modules are illustrated in the source file usrsub.c.  As shipped with the RM/COBOL release, the source module usrsub.c merely produces trace messages when the COBOL-callable subprograms are called by the RM/COBOL runtime.

Note:  The special entry points, SYSTEM, DELETE, and RENAME, which were included in the C source sub.c on previous releases of RM/COBOL for UNIX, are not present in usrsub.c.  These COBOL-callable functions are now part of the runtime system and are fully documented in Appendix F:  Subprogram Library.

UNIX versions of RM/COBOL prior to 7.1 allowed an MCS to be linked into the runtime by modifying or replacing source file osmcs.c and using a Makefile generated by the customiz script; however, starting with version 7.1, a user-written MCS support module replaces this method of supporting a Message Control System.  Windows versions of RM/COBOL prior to 7.5 did not support a Message Control System; however, starting with version 7.5, a user-written MCS support module may be provided as a Windows DLL.