WHEN Statement

The WHEN statement is subordinate to a SELECT statement and is always followed by an expression enclosed in parentheses. Each WHEN statement is followed by a set of zero or more action statements preceding the next WHEN or OTHERWISE statement. This is called a WHEN group. The expression is a pair of edit scripts separated by either an equal sign (=) or a not equal set of symbols (¬=). The two scripts are run against a command and the results are compared, after the leading and trailing blanks or null values are removed. If the two are equal (or not equal, depending on the separator value), then the command is considered to have matched that WHEN statement. Such a command is acted upon by the action statements of the WHEN group and is not compared with other WHEN statements under the same SELECT statement, and it is not matched to the OTHERWISE statement.

The WHEN statement uses the following syntax:

WHEN

Parameter

Description

action_statement

Edit orders that you can specify. See Table 1 for a list of the edit orders that you can specify.

WHEN(CONSAUTH = 'I')           ! console's authority is "I/O"
WHEN(CONSNAME left 3 = 'MST')  ! console's name begins with "MST"
WHEN(WORD 2 = '')              ! command entered with no arguments
WHEN(ASTYPE = 'D')             ! command from USS persistent procedure
WHEN(CMDVERB = 'SWITCH')       ! switch command issued  -- or ....
WHEN(CMDVERB = 'I')            ! switch command issued