Appendix B. Migration

Table of Contents
Error Codes and Return Codes
Error Detection and Reporting
Environment Variables
Stems versus Collections
Input and Output Using Functions and Methods
.Environment
Deleting Environment Variables
Queuing
Trace in Macrospace
The RxMessageBox Function

This appendix lists some differences between Object Rexx and earlier versions of Rexx, and between Object Rexx for OS/2 and Open Object Rexx for Windows NT, Windows 95 and *nix environments.

Error Codes and Return Codes

Some error codes have changed and some have been added. Also, for most errors you now receive two error messages. The first should be similar or identical to the message you would have seen previously. The second provides additional and more detailed information. So, for example, where you formerly received "Invalid Call to Routine", you now get further information on what is wrong with the call.

Also, the return codes of host commands might be different.

In Windows 95, you do not get return codes for external commands that: