Date:         Tue, 17 Dec 1996 16:00:00 PST
Reply-To:     Melvin Klassen <KLASSEN@UVVM.UVIC.CA>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Melvin Klassen <KLASSEN@UVVM.UVIC.CA>
Subject:      Re: Writing out a Variable Block File

Amy Majeske <AMAJESK@CMS.CC.WAYNE.EDU> writes:
>I'm reading in a VB file of max length 1252 and trying to write out a
>VB file with the same file characteristics.  I need to switch around
>the order of some of the fields in the first 14 bytes.
 
Use:   INFILE fileref LENGTH= LRECL;
 
to obtain the actual-size of each record.
 
Then, read the first 52 bytes, and "hold" the record.
 
       INPUT @;
       ACTUAL = MIN(LENGTH(HEADER),LRECL);
       INPUT HEADER $VARYING52. ACTUAL @;
       LENHEAD = ACTUAL;
 
Now, read the remaining up-to-1200 bytes into 6 200-byte variables:
 
       LENGTH     SEG1-SEG6 $ 200;
       ARRAY SEGS SEG1-SEG6;
       ARRAY LENS LEN1-LEN6;
 
       DO OVER LENS; LENS = 0; END;  /* Initialize. */
 
       ACTUAL = LRECL - ACTUAL;
 
       SEGNUM = 0;
 
       DO WHILE (ACTUAL > 0);
         SEGNUM = SEGNUM + 1;
 
         LEN = MIN(200,ACTUAL);
         INPUT SEGS {SEGNUM} $VARYING200. LEN @ ;
         LENS {SEGNUM} = LEN;
 
         ACTUAL = ACTUAL - LEN;
 
       END;
 
Now, you know the actual-size of the record,
and the actual-size of each of the 6 "segments",
with "zero" values for the ones which weren't needed for each record.
 
>Like most VB files, some records have 200 bytes, some have 800, and
>some have the full 1252 bytes.
>My first three lines look like this:
>      DATA STUDATA;
>      INFILE STUDATA TRUNCOVER;
>      INPUT VAR1 1-2 VAR2 2-5 .... VAR100 1251-1252;
 
It's odd that VAR1 and VAR2 *both* process column '2'.
 
>The problem comes on my FILE and PUT statements.  (There's no comparable
>TRUNCOVER option for the FILE statement.)  SAS can't seem to write it
>out the same way.
 
SAS can do the following:
 
     PUT HEADER $VARYING52. LENHEAD @;
 
     DO SEG=1 TO 6;
        TEMP = LENS {SEG};
        IF TEMP > 0 THEN PUT SEGS {SEG} $VARYING200. TEMP @;
     END;