FILEDEF is your terminal (terminal 1/0 must not be blocked). PRINTER is the spooled printer. PUNCH is the spooled punch. is the spooled card reader (card reader 1/0 must not be
blocked) • DISK specifies that the virtual 1/0 device is a disk. shown in
the format, you can choose one of two forms for specifying the DISK operand. Both forms are described in "Using the FILEDEF DISK Operand." DUMMY indicates that no real 1/0 takes place for a data set. n ] is a magnetic tape. The symbolic number of the tape drive, n,
can be 1, 2, 3, or 4, representing virtual units 181, 182,
183, and 184, respectively. If n is not specified, FILEDEF
uses the existing TAPn device for the specified ddname. TAPn defaults to if there is no existing definition for the
specified ddname, or if the existing device was not TAPn. removes any existing definition for the specified ddname.
Clearing a ddname before defining it ensures that a file
definition does not exist and that any options previously
defined with the ddname no longer have effect.
r Whenever an invalid option is specified for a particular
device type, an error message is issued. Figure 8 shows valid
options for each device type. I , options PUNCH, DISK , PRINTER , TERMINAL TAPn BLOC.K, BLKSIZE t X X CHANGE, NOCHANGE t X X CONCAT DEN 1 DISP MOD X KEYLEN LIMCT LOWCASE, UPCASE 1 LRECL X X X MEMBER OPTCD PERM X X X RECFM X X 1 TRTCH X3 tTENT 7'!'RACK, X lNo options may be necessary but all disk options are accepted.
2This option is only for BDAM files.
3This option is for 7-track tapes only. DUKMYl 1 1 1 X X 12 12 1 1 12 X X 12 L- J
Each Device Type of the Figure q. Valid File Characteristics for
FILEDEF Command 90 IBM VM/370 CMS Command and Macro Reference

PER"I NOCHANGE a
FILEDEF
retains the current definition until it either is
explicitly cleared or is changed with a new FILEDEF
command with the CHANGE option. If PERM is not
specified, the definition is cleared when a FILEDEF
*
CLEAR command is executed .. merges the file definitions whenever a file definition
already exists for a ddname and a new FILEDEF command
specifving the same ddname is issued; the options
associated with the two definitions are merged. Options from the original definition remain in effect unless
duplicated in the new definition. New options are added
to the option list.
retains the current file definition, if one exists, for
the specified ddname.
is the record format of the file, where "a" can be one of
the following:
F
FB V VB U FS,FBS VS,VBS A M fixed length
fixed blocked
1
va riable length
variable blocked
1 undefined. fixed length, standard blocks
variable length, spanned records ASA print control characters2
machine print control codes
2
LRECL nnnnn is the logical record length (nnnnn) of the file, in bytes.. LRECL should not exceed 32160 bytes because of as
restrictions. BLOCK nnnnn
BLKSIZE nnnnn
is the logical block size (nnnnn) of the file, in bytes. BLOCK should not exceed 32160 bytes because of as
restrictions. If both BLOCK and BLKSIZE options are
specified, the value of nnnnn for is used and BLKSIZE is ignored.
If a CMS file is fixed and has 80-byte records, you
should specify RECFM FB BLOCK 800 LRECL 80. Performance
can be improved for CMS fixed files if the block size is
a multiple of 800. KEYLEN nnn is the size (nnn) of the key (in bytes) • value accepted is 256.
The maximum XTENT nnnnn is the
file.
number of records (nnnnn) in the extent for the
The default is 50. The maximum value is 65535. LIMe:: nnn is the maximum number of extra tracks or blocks (nnn) to
be searched. The maximum value is 256. IFB and VB should not be used with TERMINAL or READER devices. 2A and "I may be used with any of the valid RECFM settings (for example, FA, FBA, VA, VBA, etc.) M should not be used with TERMINAL devices. Section 2. Commands 91