NET/MASTER Network Control Language (NCL) Programmer's Guide

Debugging an NCL Process From Start to Finish
Debugging an NCL Process
106160 Tandem Computers Incorporated 9–69
Step 4
Set four breakpoints by using the DEBUG BREAKPOINT command, as shown in the
following screen.
Set a breakpoint at statement 42, to check the values of all variables after the
calendar line is drawn.
Set a breakpoint at statement 44, to check the values of variables at the beginning
of the DO loop that constructs the display line.
Set a breakpoint at the variable &LINELENGTH, because the current output
shows that there is a problem in constructing display lines with the correct length.
But here you encounter a problem—that is, no variables are in scope.
Set a breakpoint at termination, as a precaution against the NCL process
terminating unexpectedly, before you have a chance to check the final values of
variables.
Step by one statement by using the DEBUG STEP command, so that all variables are in
scope, as shown in the following screen.
Now set a breakpoint by using the DEBUG BREAKPOINT command at the variable
&LINELENGTH, as shown in the following screen.
List all breakpoints, by using the DEBUG LIST BREAKPOINTS command, as shown in
the following screen. You have just set four breakpoints, and so four breakpoints are
listed.
Resume execution to the first breakpoint, by using the DEBUG RESUME command, as
shown in the following screen. The first breakpoint is at the beginning of the calendar
display.
(06:57) --------------------- OPERATOR CONTROL SERVICES ----------------------
DEBUG BREAKPOINT S=42 S=44 V=LINELENGTH TYPE=WRITE T
NNM1909 NCL 000670 BREAKPOINT 1 CREATED
NNM1909 NCL 000670 BREAKPOINT 2 CREATED
NNM1942 NCL 000670 NO VARIABLES IN SCOPE
NNM1909 NCL 000670 BREAKPOINT 3 CREATED
DEBUG STEP
NNM1902 NCL 000670 SUSPENDED AT ZEX0904N.2 LINE 8
DEBUG BREAKPOINT V=LINELENGTH TYPE=WRITE
NNM1909 NCL 000670 BREAKPOINT 4 CREATED
DEBUG LIST BREAKPOINTS
NNM1919 NCL 000670 BREAKPOINT 1 ZEX0904N.42
NNM1919 NCL 000670 BREAKPOINT 2 ZEX0904N.44
NNM1919 NCL 000670 BREAKPOINT 3 TERMINATION
NNM1919 NCL 000670 BREAKPOINT 4 VBL=LINELENGTH TYPE=WRITE
NNM0999 *END* 4 BREAKPOINTS LISTED
DEBUG RESUME
NNM1905 NCL 000670 RESUMED
Calendar for: FEB 2020
Sun Mon Tue Wed Thu Fri Sat
NNM1902 NCL 000670 SUSPENDED AT ZEX0904N.42 BP 1 LINE 43
---------- ------------------ NonStop NET/MASTER D30 ---------------- --------
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