Using %STACK to Display the Stack

Displaying the Stack without Variables

The process execution stack without variables appears when you first enter the %STACK utility or when you type *F at the Stack Display Action prompt.

Displaying the Stack with a Specific Variable

Enter *V at the Stack Display Action prompt. This will prompt you for the name(s) of the local variable(s) you want to track through the stack. Specify a single variable or a comma-separated list of variables. It returns the names and values of all local variables. In the following example, the variable e is being tracked and the display is sent to the Terminal by pressing Return

Stack Display Action: *V 
Now loading variable information ...   2  done.
Variable(s): e
Display on 
Device: <RETURN>

Displaying the Stack with All Defined Variables

Enter *P at the Stack Display Action prompt to see the process execution stack together with the current values of all defined local variables.

Displaying the Stack with All Variables, including State Variables

Enter *A at the Stack Display Action prompt to display all possible reports. Reports are issued in the following order:

• Process state intrinsic variables

• Process execution stack with the names and values of all local variables

Moving through %STACK Display

If a %STACK display fills more than one screen, you see the prompt -- more -- in the bottom left corner of the screen. At the last page, you see the prompt -- fini --. Type ? to see key presses you use to maneuver through the %STACK display.

- - - Filter Help - - -
<space> Display next page. 
<return> Display one more line. 
T Return to the beginning of the output. 
B Back up one page (or many if arg>1). 
R Redraw the current page. 
/text Search for \qtext\q after the current page. 
A View all the remaining text. 
Q Quit. 
? Display this screen 
# specify an argument for B, L, or W actions. 
L set the page length to the current argument. 
W set the page width to the current argument.

You enter any of the commands listed above whenever you see the -- more -- or -- fini -- prompts.

For the B, L and W commands, you enter a numeric argument before the command letter. For instance, enter 2B to move back two pages, or enter 20L to set the page length to 20 lines.

Be sure to set your page length to the number of lines which are actually displayed; otherwise, when you do a page up or down, some lines may not be visible. The default page length is 23.

Displaying Variables at Specific Stack Level

To see the variables that exist at a given stack frame level, enter ?# at the Stack Display Action prompt, where # is the stack frame level. The following example shows the display if you request the variables at level 1.

Stack Display Action: ?1 
The following Variables are defined for Stack Level: 1
E 
Stack Display Action:

You can also display this information using the %SYS.ProcessQueryOpens in a new tab VariableList class query.

Displaying Stack Levels with Variables

You can display the variables defined at all stack levels by entering ?? at the Stack Display Action prompt. The following example shows a sample display if you select this action.

Stack Display Action: ?? 
Now loading variable information ... 19 
Base Stack Level: 5
A
Base Stack Level: 3
A B C D
Base Stack Level: 1
E
Stack Display Action:

Displaying Process State Variables

To display the process state variables, such as $IO, enter *S at the “Stack Display Action” prompt. You will see these defined variables (Process State Intrinsics) as listed in the following table:

Printing the Stack and/or Variables

When you select the following actions, you can choose the output device:

• *P

• *A

• *V after selecting the variables you want to display.