COBOL Manual for TNS/E Programs (H06.08+, J06.03+)

file-name
is the COBOL file-name (the file-name in a file description entry).
ASSIGN clause
associates file-name with system-file-name or define-name-literal. Only the
first system-file-name or define-name-literal has meaning. The compiler ignores
subsequent names and literals and issues a warning.
system-file-name
is either the name of a disk file or the special file name #DYNAMIC or #TEMP. Quotation
marks must enclose system-file-name unless it is a COBOL word or begins with a dollar
sign ($), a backward slash (\), or a number sign (#). For more information about operating
system file names, see the Guardian Procedure Calls Reference Manual.
define-name-literal
is a nonnumeric literal. It represents the name of a DEFINE of class MAP that is associated
with a disk file. Quotation marks must enclose define-name-literal. For information
on DEFINE names, see DEFINEs (page 593).
RESERVE clause
enables or prevents sequential block buffering on input and buffered cache on output, or
enables or prevents HP COBOL Fast I-O for both input and output, for a disk file, depending
on the value of number. The access mode of the file must be SEQUENTIAL.
number
is a numeric literal, an unsigned integer.
number must be in the range 1 through 32, and its value is interpreted:
EffectValue of number
No buffering or HP COBOL Fast I-O.1
Sequential block buffering on input and buffered cache on output if
the assigned file qualifies.
2
HP COBOL Fast I-O if the assigned file qualifies; if not, sequential block
buffering for input and buffered cache for output if the assigned file
qualifies; otherwise normal I-O.
3 or greater
number is the number of blocks to buffer.
CAUTION: Do not use sequential block buffering for a file opened for shared access. If you do,
a process could read outdated data while another process alters the file. For information on shared
access, see OPEN (page 375).
128 Environment Division