System Exit Definitions

The REXX interpreter supports the system exits listed below. Exit subfunctions link to more information, including:

• When REXX calls the exit
  
• The default action when the exit is not provided or the exit handler does not process the subfunction
  
• The exit action
  
• Applicable continuations
  
• The subfunction parameters

The system exits and their subfunctions are:

RXFNC

is the external function call exit.

The variable pool interface is fully enabled during calls to this exit.

RXFNCCAL

calls an external function.
RXCMD
is the subcommand call exit.

The variable pool interface is fully enabled during calls to these exits.

RXCMDHST

calls a subcommand handler.
RXMSQ
is the external data queue exit.

The variable pool interface is enabled for RXSHV_EXIT requests during calls to these exits.

RXMSQPLL

pulls a line from the external data queue.
RXMSQPSH
places a line on the external data queue.
RXMSQSIZ
returns the number of lines on the external data queue.
RXMSQNAM
sets the active external data queue name.
RXSIO
is the standard input and output exit.

The PARSE LINEIN instruction and the LINEIN, LINEOUT, LINES, CHARIN, CHAROUT, and CHARS built-in functions do not call the RXSIO exit.

RXSIOSAY

writes a line to the standard output stream for the SAY instruction.
RXSIOTRC
writes a line to the standard error stream for REXX trace or REXX error messages.
RXSIOTRD
reads a line from the standard input stream for PULL or PARSE PULL.
RXSIODTR
reads a line from the standard input stream for interactive debug.
RXHLT
is the halt processing exit.

Because the RXHLT exit is called after every REXX instruction, enabling this exit slows REXX program execution. The RexxSetHalt function can halt a REXX program without between-instruction polling.

RXHLTTST

tests for a HALT condition.
RXHLTCLR
clears a HALT condition.
RXTRC
is the external trace exit.

Because the RXTRC exit handler is called after every REXX instruction, enabling this exit slows REXX program execution. The RexxSetTrace function can turn on REXX tracing without the between-instruction polling.

RXTRCTST

tests for an external trace event.
RXINI
is the initialization exit.

This exit is called as the last step of REXX program initialization. The variable pool interface is fully enabled during calls to this exit.

RXINIEXT

allows additional REXX procedure initialization.
RXTER
is the termination exit.

This exit is called as the first step of REXX program termination. The variable pool interface is fully enabled during calls to this exit.

RXTEREXT

processes REXX procedure termination.

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