This section discusses the support of standard REXX features such as
SAY and TRACE statements, PULL and PARSE EXTERNAL statements,
REXX stacking, and REXX functions.
The REXX SAY and TRACE terminal I/O output statements use
CICS Terminal Control support to provide simulated line-mode
output.
Also, the SET TERMOUT command can be used to route line-mode
output into a temporary storage queue.
The REXX PULL and PARSE EXTERNAL terminal I/O input statements use
CICS Terminal Control support to provide simulated line-mode
input.
Notes:
- PULL (or PARSE PULL) first attempts to
pull a line from the program stack and, only if it is empty,
issues a read to the terminal.
- Attempting to perform
terminal
line-mode input from a REXX exec that is running as part of
a non-terminal attached transaction, is an error, which
causes the exec to terminate with an error message.
Each user has
a shared program stack between multiple generations of
REXX execs. This single automatic program stack is not
named. If named program stacks are desired, use the
RLS
LPUSH,
LQUEUE, and LPULL commands.
REXX/CICS supports the standard SAA Level 2 built-in
function set, with the following exceptions:
- Stream I/O functions are not supported.
- The USERID
function returns a 1 to 8 character CICS user ID if the
user is signed on.
If the CICS user has not signed on and a default user has been
specified for the CICS region (by the CICS Systems Programmer
specifying DFLTUSER in the CICS startup parameters) then
that value is used.
Note:
The default user shares REXX File System and REXX List System
directories.
- The
STORAGE function, that allows a REXX user to display
or modify the virtual storage of the CICS region.
This function can only be successfully invoked from an authorized
exec or by an authorized user.