This sets blocksize in the DCB on 1.13 whether pointing to a member or the
library or whether MACRF=(GL) or MACRF=(R).
TEST CSECT ,
PRINT NOGEN
SAVE (14,12)
LR 12,15
USING TEST,12
LA 14,SAVE
ST 13,4(,14)
ST 14,8(,13)
LR 13,14
OPEN (SYSUT1,)
EX 0,*
INEOD L 13,4(,13)
LM 14,12,12(13)
SLR 15,15
BR 14
EJECT ,
* --- TEMPS
SPACE ,
SAVE DS 18F
SYSUT1 DCB DDNAME=SYSUT1, X
DSORG=PS, X
MACRF=(GL), X
EODAD=INEOD
END ,
Data Set Name . . . : xxxxxxxxxxxxxxxxxxxxxxxx
General Data Current Allocation
Volume serial . . . : xxxxxx Allocated cylinders : 11
Device type . . . . : 3390 Allocated extents . : 16
Organization . . . : PO Maximum dir. blocks : 44
Record format . . . : U
Record length . . . : 0
Block size . . . . : 32760 Current Utilization
1st extent cylinders: 10 Used cylinders . . : 2
Secondary cylinders : 5 Used extents . . . : 1
Used dir. blocks . : 5
Number of members . : 29
LIST 7F28. ASID(X'0020') POSITION(X'+78') LENGTH(X'1000')
ASID(X'0020') ADDRESS(7FA0.) KEY(88)
00007FA0. 00000000 00000000 026C0007 06F48026 002FE5A2 05008020 00004000
00006D68
00007FC0. 02007F4A C0000000 00544800 00AB3B3C 12DDD000 00DDA468 0A000001
02097FF8
00007FE0. 30013030 00006DD8 00000000 00000000 00007FF8 00000000 00000000
80EAFA80
00008000 LENGTH(X'20')==>All bytes contain X'00'
Bob
IBM Mainframe Discussion List <[email protected]> wrote on
07/17/2014 04:04:20 PM:
> From: Thomas David Rivers <[email protected]>
> To: [email protected]
> Date: 07/17/2014 04:03 PM
> Subject: OPEN not filling in DCBBLKSI for RECFM=U data set
> Sent by: IBM Mainframe Discussion List <[email protected]>
>
> I've been wading thru the documentation (DFSMS Using Data Sets), etc...
> trying to figure out why the DCBBLKSI field of my DCB is not
> being filled in for a RECFM=U data set for INPUT. (Non-LBI)
>
> In particular, I want to allocate a buffer of sufficient size to hold
> any block
> we might read for a pre-existing RECFM=U data set.
>
> I put zeros into the DCB before the OPEN; then I do the OPEN...
expecting
> the DCB to have the DCBBLKSI field set to the block size...
>
> But - it remains zero.
>
> The JCL (well, an SVC 99 actually) doesn't specify a BLKSIZE for the
file.
>
> But - the file is catalogued, I would have expected the DCBBLKSI field
> to get the BLOCK SIZE from the catalog?
>
> Does anyone know why the DCBBLKSI field would not be filled in ?
>
> The example code for determining the # of bytes read (from IBM's doc)
> determines the blksize after the READ (+CHECK) macros are issued.
> Is it possible that the blksize for a RECFM=U cannot be determined at
> OPEN time, but only after a READ?
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