Using List Input (2)

Reading Free-Format Data

Using List Input

Processing List Input

It's important to keep in mind that list input causes SAS to scan the input lines for values rather than read from specific columns. When the INPUT statement is put in the context of a DATA step and submitted for processing, the input pointer is positioned at column 1 of the raw data file, as shown below.

     data perm.survey;
        infile credit;
        input Gender $ Age Bankcard FreqBank Deptcard 
              FreqDept;
     run;

V---+----10---+----20

MALE 27 1 8 0 0

FEMALE 29 3 14 5 10

FEMALE 34 2 10 3 3

The first field is read until a blank space is encountered. The blank space indicates the end of the field, and the data value is assigned to the program data vector for the first variable in the INPUT statement.

1---V----10---+----20

MALE 27 1 8 0 0

FEMALE 29 3 14 5 10

FEMALE 34 2 10 3 3

The record is scanned until the next nonblank space is found, and the second value is read until another blank is encountered. Then the value is assigned to its corresponding variable in the program data vector.

1---+--V-10---+----20

MALE 27 1 8 0 0

FEMALE 29 3 14 5 10

FEMALE 34 2 10 3 3

This process of scanning ahead to the next nonblank column, reading the data value until a blank is encountered, and assigning the value to a variable in the program data vector continues until all the fields are read and values assigned to variables in the program data vector.

When the DATA step has finished executing, you can display the data set using the PRINT procedure. The following code produces the output below.

proc print data=perm.survey; run;

Obs	Gender	Age	Bankcard	FreqBank	Deptcard	FreqDept
1	MALE	27	1	8	0	0
2	FEMALE	29	3	14	5	10
3	FEMALE	34	2	10	3	3
4	MALE	35	2	12	4	8
5	FEMALE	36	4	16	3	7
6	MALE	21	1	5	0	0
7	MALE	25	2	9	2	1