XSYSTRAP

NM and CM callable (differences noted below).

Enables or disables a user-written system trap handling procedure.

Syntax

             I*V     I*
   XSYSTRAP(plabel,oldplabel);




	NOTE: Any user trap handler cannot perform a GOTO out of that procedure. Performing an ESCAPE (Pascal) or completing the trap handling procedure are the only valid ways to return. The state of the process and the program results are not predictable after a non-local GOTO statement.

Parameters

plabel

(NM) 32-bit signed integer by value (required)

(CM) 16-bit signed integer by value (required)

Passes the external-type label of the trap handling procedure. If the value is 0, the trap handler is disabled.

oldplabel

(NM) 32-bit signed integer by reference (required)

(CM) 16-bit signed integer by reference (required)

Returns the plabel of the process's previous software library trap handler. If no plabel was previously configured, 0 is returned.

Operation Notes

When a program begins execution, the user-written system trap handler is disabled automatically. When enabled by the XSYSTRAP intrinsic, and subsequently activated by an error, the user-written system trap handler assumes control.

The trap handler can be enabled or disabled by calling the XSYSTRAP intrinsic.

Condition Codes

CCE (2): Request granted. Trap enabled.
CCG (0): Request granted. Trap disabled.
CCL (1): Request denied. An illegal plabel was specified.

Related Information

Manual: Trap Handling Programmer's Guide

XSYSTRAP

Technical documentation

» Table of Contents

» Index

Syntax

Parameters

Operation Notes

Condition Codes

Related Information