TACL Reference Manual

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UTILS:TACL Commands and Functions

HP NonStop TACL Reference Manual—429513-018

8-18

ALTER DEFINE Command

Considerations

•

An ALTER DEFINE command affects existing DEFINE statements only and does

not change the working attribute set. Similarly, an ALTER DEFINE command

affects DEFINEs for the current TACL process only; any DEFINE that was propa-

gated from the current TACL to another process is unchanged.

•

Because the CLASS attribute establishes new attributes for a DEFINE, you should

keep these points in mind when you use the ALTER DEFINE command:

Attributes are altered in the order in which they are specified in the ALTER

DEFINE command.

If you include the CLASS attribute, all new attributes are established for the

DEFINE; any existing attributes are erased (including any attributes preceding

CLASS in the ALTER command itself). The new attributes are those

associated with the specified CLASS, and each attribute has its initial setting.

You cannot alter an attribute that is not valid for the class of that DEFINE. For

example, if =DFILE is CLASS TAPE, this command produces this error:

32> ALTER DEFINE =DFILE, FILE $MUNCH.NUMBERS.DIGIT

There is no attribute "FILE" for the current class

•

Before a DEFINE is altered, the ALTER DEFINE command checks for consistency

among the new attribute values specified and the other existing attributes of the

DEFINE. If the attributes are incomplete or inconsistent, an error occurs and no

changes are made to the DEFINE.

•

When a backup TACL process takes over, TACL deletes existing DEFINEs.

•

To obtain error information, use the #ERRORNUMBERS Built-In Variable on

page 9-160.

Example

This ALTER DEFINE command changes the DEVICE attribute in the DEFINEs named

=ONE and =TWO so that when the DEFINE is opened, the tape process searches for

the tape files MAYRCDS and JUNRCDS on the tape mounted on tape drive $TAPE1:

27> INFO DEFINE (=ONE, =TWO), DETAIL

DEFINE NAME=ONE

CLASS TAPEVOLUME 4335

LABELS ANSI

FILEID MAYRCDS

DEVICE $TAPE

DEFINE NAME =TWO

CLASS TAPE

VOLUME 4335

LABELS ANSI