The CHANGE subcommand of DISPLAY

This subcommand is valid only with the READ UPDATE function.

The CHANGE subcommand allows you to change the following:

The name
The RBA (relative byte address) of the index entry displayed
The RBA of the segment specified
The compression count (or the entry identifier byte or both)

The changed entry is displayed. Enter the NEXT subcommand or a null line to display the next entry.

Syntax of the CHANGE subcommand of DISPLAY

  CHANGE [ENTRY(entryname) CLASS(classname)]|[SEGMENT(segment-name)]
         [GENERIC]
         [RBA(rba)]
         [COMP(xx)]
         DUPLICATE|NODUPLICATE

where:

ENTRY(entryname)

Specifies the index entry where the display begins. If you do not specify an entry name, the display begins at the first entry in the index block; the entry name can be from 1 to 255 alphanumeric characters, which can be enclosed in quotation marks or not, and can contain hexadecimal data.

To specify a mixed-case entry name, you must enclose entryname in quotations. If you do not enclose entryname in quotations, alphabetic characters in entryname are treated as uppercase characters, regardless of the case in which you enter them.

If you specify an entry name, you must specify a class name.

CLASS(classname)

Must be one of the following:

GROUP
USER
DATASET
The class name of the general resource

The length of name plus the compression count cannot exceed 255. To create a fully compressed name, specify ENTRY (‘ ’), where the entry name is a null string, with a nonzero compression count. For a discussion of compression and an explanation of index blocks and encoding, see Index entries.

SEGMENT(segment-name)

Specifies the segment RBA to be changed.

The BASE segment cannot be specified as the segment name.

The ENTRY and CLASS keywords and the SEGMENT keyword are mutually exclusive. If both are specified, SEGMENT is ignored.

If you specify SEGMENT, only the RBA (relative byte address) of the SEGMENT is changed.

GENERIC

Indicates that the index entry name specified in ENTRY(entryname) is a generic name.

RBA(rba)

The value of rba can be from 1 to 8 hexadecimal characters or from 1 to 10 decimal characters.

COMP(xx)

The front-end compression count. xx is limited to one less than the length of the entry, and never exceeds 254. xx can be specified as decimal or hexadecimal characters.

DUPLICATE

Means that you want to make the entry a duplicate of the entry immediately following. This entry that immediately follows might be on the same block or appear at the beginning of the next block.

NODUPLICATE

Means that you do not want the current entry to be a duplicate of the entry immediately following.

There is no default on this keyword; if you do not specify DUPLICATE or NODUPLICATE, the entry identifier byte is not changed. It remains at its previous setting.

Specify only those keywords that you want to change. The others remain at their previous settings.

The BLKUPD command does not perform any checking to see if you have specified the appropriate keyword values to be changed. You must be very careful because specifying an incorrect keyword value or omitting a keyword and its value can produce unpredictable results.