IBM AS/400 manual Accessing Tape Devices

Accessing Tape Devices

*..	1 ...	+...	2 ...	+	... 3 ...	+	... 4	...+...	5 ...	+...	6 ...	+...	7 ...	+...	*
FFilename++IPEASFRlen+LKlen+AIDevice+.Keywords+++++++++++++++++++++++++++++
FPRINT		O	F	132			PRINTER PRTCTL(LINE)
*..	1 ...	+...	2 ...	+	... 3 ...	+	... 4	...+...	5 ...	+...	6 ...	+...	7 ...	+...	*
DName+++++++++++ETDsFrom+++To/L+++IDc.Keywords+++++++++++++++++++++++++++++
DLINE				DS
D SpBefore					1		3
D SpAfter					4		6
D SkBefore					7		9
D SkAfter					10		12
D CurLine					13		15	0
*..	1 ...	+...	2 ...	+	... 3 ...	+	... 4	...+...	5 ...	+...	6 ...	+...	7 ...	+...	*
CL0N01Factor1+++++++Opcode(E)+Factor2+++++++Result++++++++Len++D+HiLoEq.￿															...
C					EXCEPT
C	01CurLine				COMP		10							49

C01

CAN

49

MOVE

'3'

SpAfter

*..

1 ...

+...

2

...+

... 3 ...

+

... 4 ...

+...

5 ...

+...

6 ...

+...

7 ...

+...

*

OFilename++DF..N01N02N03Excnam++++B++A++Sb+Sa+

OPRINT

E

01

O

N01N02N03Field+++++++++YB.End++PConstant/editword/DTforma￿t++

O

DATA

25

Figure

161.

Example of the PRTCTL Option

On the file description specifications,

the PRTCTL keyword is specifi

PRINT

file.

The

name

of

the associated

data

structure is

LINE.

The LINE data structure is defined on

the input specifications as h

subfields

that

are

predefined

for

the

PRTCTL data structure. The f

in positions 1 through 12 are used to

supply space and skip informa

generally

specified

in

positions

40

through

51

of

the

output specifi

PRTCTL

keyword

allows

you

to

change

these

specifications

within

the

pr

In

this

example,

the

value

in

the

SpAfter

subfield is

changed

to

3

the

CurLine (current

line

count

value)

subfield

is

equal

to

10.

(Assum

cator

01

was

set

on

as

a

record

identifying

indicator.)

Accessing Tape Devices

Use the SEQ device specifications whenever you write to a tape fi variable-length records to a tape file, use the RCDBLKFMT parameter of command CRTTAPF or OVRTAPF. When you use the RCDBLKFMT parameter,

the length of each record to be written to tape is determined by

¹	the	highest		end	position specified in the output specifications
¹	if	you	do	not	specify	an end position, the compiler calculates t
	from	the	length		of the	fields.

Read variable-length records from tape just like you would read rec sequentially organized file. Ensure the record length specified on t specification accommodates the longest record in the file.

Chapter 17. Accessing Externally Attached325 Devices