z/OS Version 2 Release 3 Using REXX and z/OS UNIX System Services IBM SA23-2283-30 Note Before using this information and the product it supports, read the information in “Notices” on page 259. This edition applies to Version 2 Release 3 of z/OS (5650-ZOS) and to all subsequent releases and modifications until otherwise indicated in new editions. Last updated: 2019-02-16 © Copyright International Business Machines Corporation 1996, 2018. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents List of Figures....................................................................................................... xi List of Tables.......................................................................................................xiii About this document............................................................................................xv Who should read Using REXX and z/OS UNIX System Services................................................................xv Finding more information about REXX.......................................................................................................xv How to read syntax diagrams.....................................................................................................................xv Symbols.................................................................................................................................................xv Syntax items.........................................................................................................................................xvi Syntax examples.................................................................................................................................. xvi z/OS information.......................................................................................................................................xvii How to send your comments to IBM.....................................................................xix If you have a technical problem................................................................................................................xix Summary of changes............................................................................................xx Summary of changes for z/OS Version 2 Release 3 (V2R3)...................................................................... xx Summary of changes for z/OS Version 2 Release 2 (V2R2)..................................................................... xxi z/OS Version 2 Release 1 summary of changes....................................................................................... xxi Chapter 1. Using TSO/E REXX for z/OS UNIX processing......................................... 1 Host command environments for z/OS UNIX processing...........................................................................1 The SYSCALL environment...........................................................................................................................2 Running a REXX program from TSO/E or MVS batch.............................................................................2 Establishing the SYSCALL environment.................................................................................................2 Ending the SYSCALL environment..........................................................................................................3 Establishing and deleting the signal interface routine.......................................................................... 3 The SH environment.................................................................................................................................... 4 Running a REXX program from the z/OS shells or from a program.......................................................4 Using external functions and subroutines............................................................................................. 4 The TSO command environment................................................................................................................. 5 Command input...................................................................................................................................... 5 Command output....................................................................................................................................6 Return codes...........................................................................................................................................6 Examples................................................................................................................................................ 6 Variable scope..............................................................................................................................................6 Writing setuid and setgid REXX programs...................................................................................................7 Input and output for z/OS UNIX processing................................................................................................7 Using standard input, output, and error (file descriptors 0, 1, and 2).................................................. 7 Using SYSCALL commands.....................................................................................................................7 Using EXECIO..........................................................................................................................................8 Exit status from a REXX program........................................................................................................... 8 Tokens returned from the PARSE SOURCE instruction...............................................................................8 Running from a z/OS shell or from a program....................................................................................... 8 Running from TSO/E or batch.................................................................................................................9 Using the REXX signal services....................................................................................................................9 Using immediate commands.....................................................................................................................10 Moving a REXX program from TSO/E to a z/OS shell................................................................................ 11 Using argv and environment variables.................................................................................................11 Customizing the z/OS UNIX REXX environment....................................................................................... 12 Performance in the SYSCALL environment..........................................................................................12 Authorization..............................................................................................................................................13 iii Chapter 2. z/OS UNIX REXX programming services...............................................15 Creating a z/OS UNIX REXX environment from an application................................................................ 15 Running the REXX program....................................................................................................................... 16 Example: C/370 program.......................................................................................................................... 17 Chapter 3. The syscall commands........................................................................ 19 Specifying a syscall command...................................................................................................................19 Specifying numerics............................................................................................................................. 20 Specifying strings................................................................................................................................. 20 Using predefined variables........................................................................................................................ 20 Return values............................................................................................................................................. 21 Returned from the SYSCALL environment...........................................................................................21 Returned from the SH environment.....................................................................................................21 Syscall command descriptions..................................................................................................................22 access................................................................................................................................................... 22 acldelete............................................................................................................................................... 23 acldeleteentry...................................................................................................................................... 23 aclfree...................................................................................................................................................24 aclget...................................................................................................................................................