PS TEXT FORMAT Reference Manual

Expressions
11387 Tandem Computers Incorporated 5-19
ARG Function The ARG function processes macro or user-function arguments; you may
use it only in macros or functions.
ARG ( i-exp [ , b-exp ] )
ARG ( n ) or ARG ( n,#b-exp ), where b-exp evaluates to “false,” returns
the value of the n th argument in the list of arguments passed to the macro
by the invocation command.
ARG ( n,#b-exp ), where b-exp evaluates to “true,” returns the actual
string that was passed as the n th argument. For example, assume the
macro PEEKPAGE contains the following:
The page number is \(ARG(1)\).
This number is stored in \(ARG(1,1)\).
The invocation command \PEEKPAGE SYS_PAGENUMBER tells the
macro to print the actual page number (in this example 3):
The page number is 3.
This number is stored in SYS_PAGENUMBER.
If n is greater than the number of arguments in the list, TFORM issues a
“value out of range” error. If n is zero, the ARG function returns the actual
number of arguments that were passed in the current invocation. (N,S)