HP 3000 Manuals HP 3000 Manuals
On Call Statements and Compiled Subunits
The following example illustrates the behavior of the ON ERROR CALL
statement across compiled subunit calls. The ON HALT CALL and ON END
CALL statements behave the same way.
Examples
Interpreted Program External Subunits
---------------------------------------------------------------------------------------
10 ON ERROR CALL Errsub 100 SUB Extproc
20 GLOBAL EXTERNAL Extproc 110 ON ERROR CALL Blob
30 CALL First_sub 120 CALL Squiggle
. .
. .
. .
500 SUB First_sub 400 SUBEND
. 410 SUB Squiggle
. 420 PRINT 1/0
. 430 .
600 CALL Extproc .
610 PRINT 1/0 .
. 500 SUBEND
. 510 SUB Blob
. .
700 SUBEND .
720 SUB Errsub .
. 590 SUBEND
.
.
800 SUBEND
Line Result of Executing Line
10 Errsub will handle errors.
600 Control transfers to Extproc. Now Errsub does not
handle errors.
110 Blob will handle errors.
420 Error occurs (division by zero). Control transfers to
Blob.
590 Control returns to line 430.
400 Control returns to First_sub (line 610). Now Errsub
handles errors again.
610 Error occurs (division by zero). Control transfers to
Errsub.