Debugging in Menu Mode › Activity Screens › Snap Screen

Snap Screen

Purpose

The Snap screen lets you create and write a dump to the DC/UCF log at any point in the debugging session, in order to make a hard copy of storage contents.

Remember: To obtain a hard copy of the Snap dump, use the Batch Command Facility utility.

The specification area of the Snap screen looks like:

SNAP:   (A-AREA/T-TASK)     TITLE:
SKIP:   (1-ONE LINE/2-TWO LINES/3-THREE LINES/T-TOP OF NEXT PAGE)

AREA ONLY:
     BEGIN SNAP AT:

     LENGTH:          -OR-    END SNAP AT:

Field Options

These are the field options for this area:

SNAP: (A-AREA/T-TASK)

• Arequests a dump of the memory area specified in the fields in the Area Only section of the screen
• T requests a dump of all resources associated with the executing task

This is a required field on the Snap screen.

TITLE:

Specifies an optional title for the snap. The title can contain up to 42 characters. Do not enclose the title in quotation marks. An apostrophe in the title must be coded as two single quotes. When a title is not specified, a default title is written to the log:

USER user-id

SKIP: (1-ONE LINE/2-TWO LINES/3-THREE LINES/T-TOP OF NEXT PAGE)

Indicates the carriage control that will be used for placement of the title:

• 1 skips one line
• 2 skips two lines
• 3 skips three lines
• T skips to the top of the next page

If you specify nothing, two lines are skipped.

BEGIN SNAP AT:

Specifies the location at which to begin the snap. The beginning location can be a debug expression that resolves to an address for which you have retrieval security. This field is required when snapping an area.

LENGTH:

Indicates the number of bytes to be snapped.

END SNAP AT:

Indicates the ending location of the snap. The ending location can specify the same types of debug expressions as those used in the Begin Snap At field.

When you do not specify an ending location or a specific length, the default length is based on two rules:

• If the debug expression is composed of a single symbol, the data characteristics of the symbol determine the default length. The number of bytes dumped is equal to the default length of the symbol.
• If the expression does not have data characteristics, the default length is 256 bytes.