Inter-Language Communication in OS/390
- Recommended Duration:
- 3 Days
- Version
- LE for OS/390 & VM.
- Benefits
- Programmers learn to combine functions and modules written in different languages, and how each language uses arguments and parameters.
- Audience
- Experienced programmers who need to create or maintain applications using components written in various languages, or who need to use advanced language subroutine features, or the binder..
- Prerequisites
- At minimum, the student should have a strong programming background in at least one of: COBOL, PL/I, C, or Assembler.
- Major Topics
-
- Defining data (items, structures, arrays)
- Converting between null-terminated strings and traditional strings
- Working with halfword-prefixed strings
- Accessing the JCL PARM, setting the JCL return code, and using LE services
- Passing arguments by reference and by value; passing variable number of arguments; the end-of-list flag; omitting arguments; return value area
- Receiving parameters by reference and by value; handling variable number of parameters; testing end-of-list flag; testing for omitted parameters; return value; subroutines behaving like functions
- Object code formats: OBJ, XOBJ, GOFF
- The linkage editor and program binder
- Executables: load modules, program objects, DLLs
- Alternate entry points
- Shared external data
- Multi-tasking / multi-threading issues
- Dynamic calls
- Addressing concerns: AMODE / RMODE
- Module attributes (reusable, reenterable, refreshable)
- DLLs
- Visual Age PL/I for OS/390: Packages
- Exercises
- Ten hands-on exercises, one optional.