FSCBD Back to Index page
 
Prolog 
Control Block Contents 
   FSCBD DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This page documents intended Programming Interfaces that
allow the customer to write programs to obtain the services of z/VM.


  FSCBD Prolog Top of page
 
 NAME       : FSCBD
 DESCRIPTION: File System Control Block
 DSECT      : FSCBD
 FUNCTION   : Maps a based structure which names
              all fields within an FSCB. FSCBD is a PLIST
              defined for general use by routines that use
              the CMS file system. FSCBD is generated when
              the user issues the FSCBD macro.
 
 
  FSCBD Control Block Content Top of page
 

 FSCBD DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure FSCBD File System Control Block 0000 0 Character 8 FSCBCOMM File system command (e.g. RDBUF) 0008 8 Character 18 FSCBFILE File ID (name, type, and mode) 0008 8 Character 16 FSCBFNFT File name and file type 0008 8 Character 8 FSCBFN File name 0010 16 Character 8 FSCBFT File type 0018 24 Character 2 FSCBFM File mode (letter and number) 0018 24 Character 1 FSCBFML File mode letter 0019 25 Character 1 FSCBFMN File mode number 001A 26 Signed 2 FSCBITNO Relative record number to be accessed on FSREAD and FSWRITE (applies only to the non-extended FSCB) 001C 28 Address 4 FSCBBUFF Address of the input/output buffer for FSREAD and FSWRITE (also used on calls to DMSSTT for the FST address) 0020 32 Signed 4 FSCBSIZE Length (in bytes) of the input/output buffer (also used to return the record length on FSOPEN) 0024 36 Character 2 FSCBFV Record format and first flag byte 0024 36 Character 1 FSCBRECF Record format - F or V 0025 37 Bitstring 1 FSCBFLG First flag byte 'FSCBFLG' flag byte definition 1... .... FSCBTHEX X'80' Space threshold exceeded (SFS only) .1.. .... FSCBITAV X'40' Item available (CDF only) ..1. .... FSCBEPL X'20' Extended PLIST (FORM=E) ...1 .... FSCBMSG X'10' MSG=YES on FSSTATE or FSOPEN .... 1... FSCBSTW X'08' STATEW specified on FSSTATE .... .1.. FSCBCACY X'04' CACHE=YES specified .... ..1. FSCBCACN X'02' CACHE=NO specified .... ...1 FSCBRCAV X'01' Previous record null (CDF only) 0026 38 Signed 2 FSCBNOIT Number of records to be accessed on FSREAD and FSWRITE (applies only to the non-extended FSCB) 0026 38 Bitstring 1 FSCBFLG2 Second flag byte 'FSCBFLG2' flag byte definition (FORM=E only) 1... .... FSCBNMAC X'80' NOMSG=ACTIVE specified on FSOPEN .1.. .... FSCBNMNF X'40' NOMSG=NOTFOUND specified on FSOPEN ..1. .... FSCBNMOS X'20' NOMSG=OSDOS specified on FSOPEN 0027 39 Character 1 FSCBOTYP OPENTYP value 'FSCBOTYP' Values (FORM=E only) .... .... FSCBTNON X'00' OPENTYP=NONE specified 000000D9 FSCBTRD C'R' OPENTYP=READ specified 000000E6 FSCBTWR C'W' OPENTYP=WRITE specified 000000D5 FSCBTNEW C'N' OPENTYP=NEW specified 000000E7 FSCBTREP C'X' OPENTYP=REPLACE specified 0028 40 Signed 4 FSCBNORD Number of bytes actually read on FSREAD 'FSCBFST' is returned on FSOPEN. Its value is based on the OPENTYP specified and whether or not the file exists. Note that a non-extended format FSCB (FORM=E not specified) implies OPENTYP=NONE. The values are as follows: File doesn't exist . FSCBFST=A(0) File exists: Not FORM=E FSCBFST=A(Copy of 40 byte FST) OPENTYP=NONE . FSCBFST=A(Copy of 64 byte FST) OPENTYP=READ . FSCBFST=A(Copy of 64 byte FST) OPENTYP=WRITE FSCBFST=A(Copy of 64 byte FST) OPENTYP=REPLACE . FSCBFST=A(-1) OPENTYP=NEW Error, FSCBFST is unchanged 0028 40 Address 4 FSCBFST Address of a copy of the FST returned on FSOPEN The following fields apply only to the extended form FSCB (i.e., FORM=E was specified). 002C 44 Signed 4 FSCBAITN Relative record number to be accessed on FSREAD and FSWRITE (also referred to as the "alternate item number") 0030 48 Signed 4 FSCBANIT Number of records to be accessed on FSREAD and FSWRITE (also referred to as the "alternate number of items") 0034 52 Signed 4 FSCBWPTR Extended write pointer (input on FSPOINT FORM=E, output on FSOPEN) 0038 56 Signed 4 FSCBRPTR Extended read pointer (input on FSPOINT FORM=E, output on FSOPEN) 0000003C FSCBLNBY *-FSCBD Length (in bytes) of the extended FSCB
 
 
  FSCBD Storage Layout Top of page
 
          
*** FSCBD - File System Control Block
*
*     +-------------------------------------------------------+
*   0 |                       FSCBCOMM                        |
*     +-------------------------------------------------------+
*   8 |                                                       |
*     =                       FSCBFILE                        =
*     |             +-----------------------------------------+
*     |             | 1A
*     +-------------+
*
*** FSCBD - File System Control Block
          
*** Overlay for FSCBFILE in FSCBD
*
*     +-------------------------------------------------------+
*   8 |                       FSCBFNFT                        |
*     |                                                       |
*     +-------------------------------------------------------+
*  18
*
*** Overlay for FSCBFILE in FSCBD
          
*** Overlay for FSCBFNFT in FSCBD
*
*     +-------------------------------------------------------+
*   8 |                        FSCBFN                         |
*     +-------------------------------------------------------+
*  10 |                        FSCBFT                         |
*     +-------------+-----------------------------------------+
*  18 |   FSCBFM    | 1A
*     +-------------+
*
*** Overlay for FSCBFNFT in FSCBD
          
*** Overlay for FSCBFM in FSCBD
*
*     +------+------+-------------+---------------------------+
*  18 |:BFML |:BFMN |  FSCBITNO   |         FSCBBUFF          |
*     +------+------+-------------+-------------+-------------+
*  20 |         FSCBSIZE          |   FSCBFV    | 26
*     +---------------------------+-------------+
*
*** Overlay for FSCBFM in FSCBD
          
*** Overlay for FSCBFV in FSCBD
*
*                                 +------+------+-------------+
*  20 ...                      24 |:BRECF|:BFLG |  FSCBNOIT   |
*                                 +------+------+-------------+
*  28
*
*** Overlay for FSCBFV in FSCBD
          
*** Overlay for FSCBNOIT in FSCBD
*
*                                               +------+------+
*  20 ...                                    26 |:BFLG2|:BOTYP|
*     +---------------------------+-------------+------+------+
*  28 |         FSCBNORD          | 2C
*     +---------------------------+
*
*** Overlay for FSCBNOIT in FSCBD
          
*** Overlay for FSCBNORD in FSCBD
*
*     +---------------------------+---------------------------+
*  28 |         FSCBFST           |         FSCBAITN          |
*     +---------------------------+---------------------------+
*  30 |         FSCBANIT          |         FSCBWPTR          |
*     +---------------------------+---------------------------+
*  38 |         FSCBRPTR          | 3C
*     +---------------------------+
*
*** Overlay for FSCBNORD in FSCBD
 
 
  FSCBD Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
FSCBAITN       002C
FSCBANIT       0030
FSCBBUFF       001C
FSCBCACN       0025 02
FSCBCACY       0025 04
FSCBCOMM       0000
FSCBEPL        0025 20
FSCBFILE       0008
FSCBFLG        0025
FSCBFLG2       0026
FSCBFM         0018
FSCBFML        0018
FSCBFMN        0019
FSCBFN         0008
FSCBFNFT       0008
FSCBFST        0028
FSCBFT         0010
FSCBFV         0024
FSCBITAV       0025 40
FSCBITNO       001A
FSCBLNBY       0038 0000003C
FSCBMSG        0025 10
FSCBNMAC       0026 80
FSCBNMNF       0026 40
FSCBNMOS       0026 20
FSCBNOIT       0026
FSCBNORD       0028
FSCBOTYP       0027
FSCBRCAV       0025 01
FSCBRECF       0024
FSCBRPTR       0038
FSCBSIZE       0020
FSCBSTW        0025 08
FSCBTHEX       0025 80
FSCBTNEW       0027 000000D5
FSCBTNON       0027 00
FSCBTRD        0027 000000D9
FSCBTREP       0027 000000E7
FSCBTWR        0027 000000E6
FSCBWPTR       0034
 
This information is based on z/VM 6.3.0.
Last updated on 22 May 2013 at 13:50:04 EDT.
Copyright IBM Corporation, 1990, 2013