HP 3000 Manuals

FCOPY Reference Manual

SKIPEOF 

Instructs FCOPY to skip end-of-file (EOF) markers on a serial storage
device in order to position the device at the desired file before
copying.

Syntax 

         [{+}from-eofs    ][ {{+}to-eofs    }]
;SKIPEOF=[{-}             ][,{{-}           }]
         [                ][ {              }]
         [from-file-number][ {to-file-number}]
Where:

+/-                  Specifies forward (+) or reverse (-) movement.

from-eofs            Is a positive integer specifying how many files to
                     skip on the "from" device.

from-file-number     Is an integer specifying an absolute file number on
                     the "from" device.  Absolute file numbers begin with
                     1.

to-eofs              Is a positive integer specifying how many files to
                     skip on the "to" device.

to-file-number       Is an integer specifying an absolute file number on
                     the "to" device.

File Attributes 

The files that use the SKIPEOF function (either the fromfile or the
tofile, or both) must reside on unlabeled magnetic tapes, serial disks,
or cartridge tapes.  The fromfile must have read access, and the tofile 
must have write access.

Operation 

SKIPEOF lets you specify particular files on unlabeled magnetic tapes,
cartridge tapes, and serial disks.

Absolute File Numbers 

In the syntax description of the SKIPEOF function, from-file-number and
to-file-number represent absolute file numbers.  Absolute file numbers
refer to specific files on a tape or serial disk.  Tape and serial disk
files are sequentially numbered, beginning with 1.  You can use file
numbers to identify the files you want to copy.  For example, to copy
from the fourth file on a tape, specify 4 as the from-file-number,
SKIPEOF=4.

When you specify a from-file-number or a to-file-number, such as
SKIPEOF=,2, the SKIPEOF function positions the tape at the beginning of
the specified file.  The tape's position before you issue the command
does not affect the file copied.  Figure 5-6 illustrates this process.


          Figure 5-6.  Skipping Absolute File Numbers 

If you specify zero as a from-file-number or a to-file-number, FCOPY
copies from or to the first file on the tape or serial disk.

Relative File Numbers 

Both from-eofs and to-eofs represent the number of files to skip relative
to the tape's current position.  If you use a plus sign (+) to specify
forward movement, the SKIPEOF function skips forward over the specified
number of EOF marks.  Figure 5-7 shows the effect of specifying
SKIPEOF=+3.


          Figure 5-7.  SKIPEOF=+3 

If you use a minus sign (-) to specify backward movement, the SKIPEOF
function skips backward over the specified number of EOF marks plus 1,
and then skips forward one EOF mark.  This action positions the tape at
the beginning of a file, rather than at the end of the preceding file.
Figure 5-8 shows the effect of specifying SKIPEOF=-3.


          Figure 5-8.  SKIPEOF=-3 

If you specify +0 or -0 for either of these parameters, SKIPEOF positions
the tape at the beginning of the current file, as illustrated in figure
5-9.


          Figure 5-9.  SKIPEOF=+0 

Examples 

The command below instructs FCOPY to skip to the fourth file of *THISTAPE
and to the fifth file of *THATTAPE before copying data from *THISTAPE to
*THATTAPE:

     >FROM=*THISTAPE;TO=*THATTAPE;SKIPEOF=4,5 

In the example below, FCOPY copies information from the file three files
ahead of *TAPES's current position to the seventh file of *TAPE2.  If,
for example, the current position of *TAPES is at the second file mark,
FCOPY begins to copy from the sixth file.  No matter where skipping
begins on *TAPE2, FCOPY copies data to its seventh file:

     >FROM=*TAPES;TO=*TAPE2;SKIPEOF=+3,7 

The FCOPY command below skips to the fifth file of *TAPEA and positions
*TAPEB four files back from its current position.  FCOPY copies file #5
of *TAPEA to the selected file on *TAPEB:

     >FROM=*TAPEA;TO=*TAPEB;SKIPEOF=5,-4 

If you are copying several files from or to the same device, you can use
an asterisk (*) to refer to the "from" or "to" device in the previous
command.  For example, the command below copies file #2 of *TAPES, the
"from" device in the previous example, to file #8 of *TAPE2, the "to"
device in the previous example:

     >FROM=*;TO=*;SKIPEOF=2,8 

In the example below, FCOPY does not move *MYTAPE from its current
position, but positions $CTUL, a terminal cartridge tape unit (refer to
chapter 6), at the ninth file.  FCOPY then copies the file at the current
position of *MYTAPE to the ninth file of the cartridge tape:

     >FROM=*MYTAPE;TO=$CTUL;SKIPEOF=,9 

MPE/iX 5.0 Documentation