FCOPY Reference Manual (32212-90008)

Chapter 5 99
FCOPY Functions
SUBSET
A pattern list is a set of octal or decimal numbers, each representing one byte. A pattern
list is delimited by number signs (#), and can contain no more than 35 integers. You can
continue a pattern list from one line or record to the next, but you cannot specify the
continuation between elements of an individual pattern. Each decimal integer must be
within the range 0 through 255, and each octal integer must be within the range 0 through
377.
If the specified character string or pattern list does not exist entirely within a particular
record in the fromfile, the record is not considered to be part of the defined subset.
Defining Subsets from Record Ranges
You can use record ranges to specify up to 255 subsets. FCOPY sequentially copies the
subsets in the order you list them. They must be in numerical order, and they may not
overlap.
Using the SUBSET Function Alone
You can use SUBSET alone to copy a disk file to a duplicate that uses less disk space. If you
use SUBSET to copy data from a disk file that does not fill the space allocated to it to a new
disk file, the resulting tofile is only as large as the actual contents of the fromfile. FCOPY
does not copy the unused space. For example, the command below only copies 20 records
from TEST1:
>FROM=TEST1;TO=TEST2;NEW;SUBSET
EOF FOUND IN FROMFILE AFTER RECORD 19
20 RECORDS PROCESSED * * * 0 ERRORS
If you exit FCOPY and return to MPE, you can observe the effect of the FCOPY command
by using LISTF to list the characteristics of the two files and compare them. For example:
LISTF TEST@,2
ACCOUNT= SUBSYS GROUP= EDITOR
FILENAME CODE--------------LOGICAL RECORD----------SPACE----
SIZE TYPE EOF LIMIT R/B SECTORS #X MX
TEST1 80B FA 20 1023 1 128 1 8
TEST2 80B FA 20 20 1 21 7 7
Copying User Labels Only
Use SUBSET=0,0 to copy just the user labels from a disk file. For example, the following
command copies the user labels from the disk file LABELD to the labeled magnetic tape
*TAPE.
>FROM=LABELD;TO=*TAPE;SUBSET=0,0
Magnetic Tape Subsets
FCOPY selects magnetic tape subsets by logical record number. If you need to use physical
block subsets, you can temporarily define a logical record length equal to the physical
record length. A subset may not extend over an EOF mark or a tape mark boundary on
magnetic tape.