Assignil'j3 Symbolic Values - IBM System 360 User Manual

The command procedure is entered in the data set or into a member of
a command procedure library with the EDIT command. The descriptive
qualifier normally used is CLIST. You must also use the SAVE subcommand
to save the command procedure.
ASSIGNING SYMBOLIC VALUES
When you enter the canmands and subcommands in the procedure, you can
include symbolic values for any operand or value
of
an operand. A
symbolic value is characterized by a name preceded by an ampersand (&).
The name consists of letters and numbers, but it must begin with a
letter. For example, if you want to substitute the symbolic value
&DSNAME for the 'data set name' operand in the following statement:
EDIT data set name NEW DATA
enter:
edit &dsname new data
If the symbolic value must be immediately followed by a special
character (such as a right parenthesis, apostrophe, or period), the
symbolic value must end with a period. For example, if you want to
substitute the symbolic value &DSNAME for the "data set name" operand in
the following expression:
DATASET(data set name)
enter:
dataset(&dsname.)
A command procedure that contains symbolic values must begin with a PROC
statement. The symbolic values that are identified by ampersands are
defined by the operands of the PROC statement. There are two types of
symbolic va lues:
• Positional -- a required operand that must be replaced by the user
in the EXEC command. It can contain up to 252 characters •
• Keyword -- an optional operand that can be replaced by the user if
desired. It can contain up to 31 characters.
The PROC statement must indicate the number of positi onal symbolic
values to be supplied by the user. (If none of the symbolic values are
positional, enter zero.) After the number, list the positional symbolic
values omitting their ampersands,. After the positional symbolic values,
list the keyword symbolic values omitting their ampersands. For
example, assume you have the following command procedure named PR39:
PROC
3
INPUT OUTPUT LIST LINES()
ALLOCATE DATASET ( &INPUT.) FILE (INDATA) OLD
ALLOCATE DATASET(&OUTPUT.) BLOCK(lOO) SPACE(300,10)
ALLOCATE DATASET ( &LIST .• ) FILE (PRINT)
CALL PROG 2 '&LINES.'
END
Using and Writing Command Procedures 83