FSTSECT FSTSECT defines the file status table (FST) which describes the attributes cf a file on a CMS virtual disk. FSTSBCT is invoked by the macro FSTB. The file status tables for all files on the disk are grouped into SOO-byte disk records
referred to as file status table blocks (FSTEs). Each file status table block can
accommodate up to 20 file status tables.
o S 10 1S 20 Hexadecimal
Displacement
------------ 0 S 10 14
16 lS 1A 1C lE 1F 20 24
26 FSTN FSTT FSTD FS'IliP FSTRP FSTM FSTIC FSTCL 1*1 1*2 FSTIL FS'IIEC FSTYR Field
Name Field Description, Contents, Meaning -------------------------------------- FSTN DS 1D Filename FSTT DS 1D Filetype FSTD DS 1F Date/tille last written FSTWP DS 1H Write pointer (item number) FSTRP DS lH Read pointer Cite. number) FSTM DS 1H Filellode FSTIC DS 1H Item count FSTFCL DS 1H First chain link FSTFV DS 1C A*1 Fixed (F)/variable (V) flag FSTFB DS 1C A*2 Flag byte (if used) to STA1!FST COp! £! §y££g§§!yl 2I!I! 2! £gll) FSTFRWX EOU X'CO' Read-only extension of read/write FSTFRW FSTFROX FSTFACT FSTFIR FSTFIW FSTFAP FSTFRO EOU BOU EQU EQU EQU EQU EOU X'SO' X'40' X'07' X'04' X'02' X'01' X'OO' disk
Read/write disk
Read-only extension of read-only
disk
File is active (one of the follcwing)
File active for reading
File active for writing
File active fro. a designated point
Read-only disk for use RDEUF FSTITAV EQU 1'40'-- ----Item availatle FSTRECAV BQU X'Ol' Previous record null FSTNOIT EQU X'OO' Null record FSTIL DS FSTDBC DS FSTYR DS FSTL BQU !!IEg!!212£! FSTFWDP EQU FSTBKWD EQU 1F
1H
1H *-FSTSECT Parameters 800------- S04 Maximum item length SOO-tyte data block count Year Size of FST in bytes (X'2S') Forward pointer to next hyperblock in storage
Backward pointer to previous hyperblock in
storage 190 IBM VM/370 Data Areas and Control Block Logic
FVSECT FVSECT is used mainly by file management and I/O routines. FVS contains save areas, work
areas, and commonly used constants. A typical use of FVS is when a reentrant I/O routine
requires a work area or save area, since the routine cannot modify itself. FVSECT is
invoked by the FVS macro. 01 I I DISK$SEG 38! REGSAV3 1-------------------------------------------------------- 781 RWFSTRG 1-------------------------------------------------------- COl ADTFVS 1------------------------------------------------------- C81 I 100 108 148 150 F65535 VFREE REGSAVO A*1 REGSAV1 FW4 F10C Section 2. CMS tata Areas and Contrel Blocks 191
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