COMPSWT, FSCB Macros COMPSWT Use the COMPSWT macro instruction to turn the compiler switch (COKPSWT) flag on or off. The COMPSWT flag is in the byte of the nucleus
constant area (NUCON). The format of the COMPSWT macro instruction is: r I [label] COMPSWT I L- label ON FSCB
________________ . _______ -J is an optional statement label.
turns the COMPSWT flag on. When this flag is on, any program
called by a LINK, LOAD, XCTL, or ATTACH macro instruction must
be a nonrelocatable module in a file with a filetype of MODULE; it is loaded via the CMS command.
turns the COMPSWT flag off. When this flag is off, any program
called by a LINK, XCTL, or ATTACH macro instruction must
be a relocatable object module residing in a file with a
filetype of TEXT or TXTLIB; it is loaded via the CMS INCLUDE command. Use the FSCB macro instruction to create a file system control block (FSCB) for a CMS input or output disk file. The format of the FSCB macro instruction is: r I [label]
! L- label
fileid
RECFM=format FSCB [fileid] [,BECFM=format] [,BUFFER=buffer] f,BSIZE=size] [,RECNO=number] [,NJREC=numrec] , _____________________________________________________ -J is an optional statement label.
specifies the CMS file identifier, which must be enclosed
in single quotation marks and separated by blanks
('filename filetype filemode'). If is omitted, is assumed.
indicates whether the records are fixed-(F) or variable­ (V) length format. The default is F. BUFFER=buffer specifies the address of an IIO buffer, from which
records are to be read or written. BSIZE=size RECNO=number
specifies the number of bytes to be read or written for
each read or write request.
specifies che record number of the next record to be
accessed, relative to the beginning of the file, record
1. default is 0, which indicates that records are to
be accessed sequentially. 30U eMS Command and Macro Reference
FSCB, FSCBD Macros NOREC=numrec specifies the
read operation.
number of records to
The default is 1.
be read in the next
1. The options RECFM, BUFFER, BSIZE, RECNO, and NOREC must all be
specified as self-defining terms.
2. You can use the same FSCB to reference several different files; you
can override the fileid, or any of the options, on the FSOPEN, or FSREAO macro instructions when you reference a file via
its FSCB. However, if the FSOPEN macro instruction is used to ready an existing file, the BSIZE and fields in the FSCB are
reset to reflect actual file characteristics.
3. You can use multiple FSCBs to reference the same file, for example,
if you wanted one FSCB for writing and a different FSCB for reading
the file. Keep in mind, however, that the file characteristics are
inherent to the file and not to the FSCB. If you establish a read
or write pointer using the RECNO option in one FSCB, that pointer
remains unchanged unless you specify the RECNO option again on the
same or any other FSCB for that file. FSCBD Use the FSCBD macro instruction to generate a DSECT for the file system
control block (FSCB). The format of the FSCBD macro instruction is: r ,
i [label] L- FSCBD label is an optional statement label. The first statement in the FSCBD macro expansion is labeled FSCBD. 1. You can use the labels established in the FSCB DSECT to modify the
fields in an FSCB for a particular file. An FSCB is created
explicitly by the FSCB macro instruction, and implicitly by the FSREAO, and FSOPEN macro instructions.
2. The FSCBD macro expands as follows: FSCBD FSCBCOMM FSCBFN FSCBFr-1 FSCBITNO FSCBBUFF FSCBSIZE FSCBFV FSCBNOIT FSCBNOFD FSCBD OSECT OS CL8 DS CL8 DS CL8 DS CL2 DS H DS A OS F OS CL2 DS H DS A Command
Filename
Filetype
Filemode
Rela ti ve record (item) number
Address of read/write buffer
Length of buffer
Record format (F or V) Number of records to be read/written
Number of bytes actually read
section 6. CMS Macro Instructions 305
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