Overview:
This module enables the student to
understand ‘F’ Specifications and READ and WRITE opcodes.
Outline:
Topics covered,
- Details of ‘F’
Specifications
- Use of two physical files.
- How to read from physical file.
- How to write in Physical file.
- How to call RPG program in CL.
Objective:
By the end of this module, the student should be
able to Understand:
- Knowing
F Specification.
- How to code RPG program by defining PF file.
- How
to run RPG program in CL program.
File Description Specifications
F Specification line is broken into following
parts.
|
Positions
|
Name
|
Entry
|
|
1-2
|
Page
|
Page number
|
|
3-5
|
Line
|
Line number
|
|
6
|
Form type
|
F
|
|
7-14
|
File name
|
Valid file name
|
|
15
|
File type
|
I
O
U
C
|
|
16
|
File designation
|
Blank
P
S
R
T
F
|
|
17
|
End of file
|
E
Blank
|
|
18
|
Sequence
|
A or Blank
D
|
|
19
|
File format
|
F
E
|
|
20-23
|
|
Blank
|
|
24-27
|
Record length
|
1-9999
|
|
28
|
Limits processing
|
L
Blank
|
|
29-30
|
Length of key field or record address
field
|
1-99
Blank
|
|
31
|
Record address type
|
Blank
A
P
|
|
32
|
Type of file organization
|
Blank
I
T
|
|
33-34
|
Overflow indicators
|
Blank
OA-OG, V
|
|
35-38
|
Key field starting location
|
Blank
1-9999
|
|
39
|
Extension code
|
Blank
E
L
|
|
40-46
|
Device
|
PRINTER
DISK
WORSTN
SPECIAL
SEQ
|
|
47-52
|
|
Blank
|
|
53
|
Continuation lines
|
Blank
K
|
|
54-59
|
Name of routine
|
Name of user-supplied routine
|
|
60-65
|
|
Blank
|
|
66
|
File addition/unordered
|
Blank
A
|
|
67-70
|
|
Blank
|
|
71-72
|
File condition
|
Blank
U1-U8
|
|
73-74
|
|
Blank
|
|
75-80
|
Comments
|
Optional
|
File description specifications describe all the files that your
program uses. The information of each file includes:
·
Filename: Name of the file
·
File Type:
ü
Input (I) : Type I to indicate an input file.
ü Output (O) :
Type O to indicate an output file.
ü Update (U) : Type
U to indicate an update file.
ü
Combine(C) : Type C
to indicate a combined (input/output) file.
·
File Designation:
ü
Blank (b) :Leave
the field blank to indicate an output
file.
ü
Fully Procedural (F) :Type
F to indicate a Full procedural file.
ü Primary File (P)
:Type P to indicate a primary file
ü
Record Address file (R) :Type R
to indicate a Record Address File.
ü Secondary File (S) :Type S to indicate a secondary
file.
ü Array or Table File (T) : Type T to indicate an array or table file.
·
File Format:
ü
Externally described (E) : Type E to indicate an externally described
file.
ü
Program described (F) : Type F
to indicate a program-described file.
·
Record Length: Length of record for program described file (maximum
9999)
·
Record Address Type:
ü
Sequential Processing (b)
ü
Program described File key field charecter. (A)
ü
Program described File key field packed decimal (P)
ü
Externally described file (K) indicates keyed file.
·
Device file:
o
WORKSTN : The file is a workstation file.
o
SPECIAL : The file is a special file.
o
PRINTER : The file is a PRINTER file.
o
DISK : The file is a DISK file.
o
SEQ : The file is a sequentially organized
file.
1) Create ‘STUD1’ physical file having 2
fields as shown below.
Columns . . . : 1
71 Edit PB01U01D/MYDDS
SEU==>
STUD1
FMT
PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++
*************** Beginning of data *************************************
0001.00 A R STDR
0002.00 A ROLL 3S 0 COLHDG('ROLL NUMBER')
0003.00 A SNAME 5A COLHDG('STUDENT NAME')
0007.00 A K ROLL
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
(C)
COPYRIGHT IBM CORP. 1981, 2002.
2) Create RPG program having name ‘RPG1’
& specify or declare file as shown below
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
H
.....H........1..CDYI....S..............1.F............................
IPF
*************** Beginning of data *************************************
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
NOTE : ‘IPF’ stands for Input prompt for FILE.
PRESS ENTER
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
H
.....H........1..CDYI....S..............1.F............................
*************** Beginning of data *************************************
'''''''
****************** End of data ****************************************
Prompt type . . . F
Sequence number . . .
'''''''
File File End of File
Filename
Type Designation File
Sequence Format
Record
Mode of Length of Record
Length
Processing Key Field Address Type
File Overflow Key Field Extn
Organization Indicator Start Loc Code
Device
File File
Continuation Exit
Entry Addition Condition
F3=Exit
F4=Prompt F5=Refresh F11=Previous record
F12=Cancel F23=Select prompt F24=More keys
For defining file user has to enter ‘FILE
NAME’, ‘FILE TYPE’, ‘FILE DESIGNATION’, ‘FILE FORMAT’,’REOCORD ADDRESS TYPE’,
and ‘DEVICE’ as shown below. As we declaring physical file so we have to
define ‘Record Address Type’ and ‘Device’. For PF we declare device of physical
file as a DISK device.
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
F
.....FFilenameIPEAF....RlenLK1AIOvKlocEDevice+......KExit++Entry+A....U
*************** Beginning of data *************************************
''''''' FSTUD1
IF E K DISK
****************** End of data ****************************************
Prompt type . . . F
Sequence number . . .
'''''''
File File End of File
Filename
Type Designation File
Sequence Format
STUD1 I F E
Record
Mode of Length of Record
Length
Processing Key Field Address Type
K
File Overflow Key Field Extn
Organization Indicator Start Loc Code
Device
DISK
File File
Continuation Exit
Entry Addition Condition
F3=Exit
F4=Prompt F5=Refresh F11=Previous record
F12=Cancel F23=Select prompt F24=More keys
After inserting the field according to
above sequence press enter 2 times to get the following screen.
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
F
.....FFilenameIPEAF....RlenLK1AIOvKlocEDevice+......KExit++Entry+A....U
*************** Beginning of data *************************************
0001.00 FSTUD1
IF E K DISK
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
Now we are going to read the content of
‘STUD1’ with ‘READ’ keyword and make it display on the screen using DSPLY
keyword.
To proceed further make use of ‘C’
specification.
Read (Read a record)
Read operation retrieves record
sequentially from a full procedural file . Record format or file name is written in the factor2 of the file that is
to be read. Indicators define in the EQ (EOF) factor get on if record is not found.
Indicators define in the LO (ER) factor get on if READ operation was not
completed successful.
Factor 1
|
|
Factor 2
|
File name / record format
(Mandatory)
|
Result Field
|
Data Structure (only for
program describe file)
|
HI
|
|
LO
|
ER (Optional)
|
EQ
|
EOF
|
So read the file as shown below.
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
FX .....FFilenameIPEAF........L..I........Device+......KExit++Entry+A....U
*************** Beginning of data *************************************
0001.00 FSTUD1
IF E K DISK
0003.03 * READ FILE
0003.05 C READ STDR 10
****************** End of data ****************************************
Prompt type . . . C
Sequence number . . .
0003.05
Level N01N02N03
Factor 1 Operation Factor 2 Result
|
READ STDR
Decimal
Length
Positions H/N/P HI
LO EQ Comment
10
F3=Exit
F4=Prompt F5=Refresh F11=Previous record
F12=Cancel F23=Select prompt F24=More keys
Hit enter which gives you a blank prompt of
‘C’ spec to do a new entry make entry as shown below.(‘ROLL’ and ‘SNAME’ are
our fields from ‘STUD1’ physical file).
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
FX .....FFilenameIPEAF........L..I........Device+......KExit++Entry+A....U
*************** Beginning of data *************************************
0001.00 FSTUD1
IF E K DISK
0003.03 * READ FILE
0003.05 C READ STDR 10
0004.00 C ROLL DSPLY
0004.01 C SNAME DSPLY
0005.00 C SETON LR
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
(C)
COPYRIGHT IBM CORP. 1981, 2002.
Above ‘DSPLY’ shows only first record of PF
file. So to define all records from ‘STUD1’ we have to use ‘DO Loop’ as shown
below.
So we will make use of ‘Indicator’ which is
define with read operation. So to define indicator we use ‘IN**’ (** means the
indicator which we define i.e. *IN10).
There are 2 types of DO loop
- DO-While Loop (DOW** – ENDDO) : This loop checks the condition
before execution.
- DO-Until Loop (DOU** – ENDDO) : This loop checks the condition
after execution.
We use to define DO** loop in opcodes. (**
means ‘Relational Operator’ )
EQ : EQual
To
LE : Less than Equal to
GT : Greater
Than
GE : Greater
than Equal to
NE : Not Equal
So define ‘DO – Loop’ as shown below.
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==> RPG1
FMT
FX .....FFilenameIPEAF........L..I........Device+......KExit++Entry+A....U
*************** Beginning of data *************************************
0001.00 FSTUD1
IF E K DISK
0003.03 * READ FILE
0003.05 C READ STDR 10
0005.00 C *IN10 DOWEQ*OFF
Prompt type . . . C
Sequence number . . .
0005.00
Level
N01N02N03 Factor 1 Operation Factor 2 Result
*IN10 DOWEQ *OFF
Decimal
Length
Positions H/N/P HI
LO EQ Comment
F3=Exit
F4=Prompt F5=Refresh F11=Previous record
F12=Cancel
F23=Select prompt F24=More keys
Now use ‘DSPLY’ keyword to display record
and complete the program as shown below.
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
FX .....FFilenameIPEAF........L..I........Device+......KExit++Entry+A....U
*************** Beginning of data *************************************
0001.00 FSTUD1
IF E K DISK
0003.03 *READ FILE
0003.05 C READ STDR 10
0005.00 C *IN10 DOWEQ*OFF
0006.00 C ROLL DSPLY
0007.00 C SNAME DSPLY
0007.04 C READ STDR 10
0007.05 * Write into File
0007.06 C WRITERSTD
0008.00 C ENDDO
0009.00 C SETON LR
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
Above program shows you the whole record
from physical file.
Now in next step we have to copy or move
content of one PF ‘STUD1’ to ‘STUD2’ so that you have to create a new physical
file ‘STUD2’ as shown below,
- Create ‘STUD2’ physical file having 2 fields as shown below.
Columns . . . : 1
71 Edit PB01U01D/MYDDS
SEU==>
STUD2
FMT
PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++
*************** Beginning of data *************************************
0001.00 A
R RSTD
0002.00 A ROLLNO 3S 0 COLHDG('ROLL NUMBER')
0003.00 A NAME 5A COLHDG('STUDENT NAME')
0007.00 A
K ROLLNO
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
(C) COPYRIGHT IBM CORP.
1981, 2002.
- In second step define ‘STUD2’ in file(F) spec as shown below
and press enter, put information of file as shown below. And read that
file in C-Specification.
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
FX .....FFilenameIPEAF........L..I........Device+......KExit++Entry+A....U
*************** Beginning of data *************************************
0001.00 FSTUD1
IF E K DISK
0002.00 FSTUD2
UF E K DISK A
0003.03 *READ FILE
0003.05 C READ STDR 10
0004.00 C READ RSTD 10
0005.00 C *IN10 DOWEQ*OFF
0006.00 C ROLL DSPLY
0007.00 C SNAME DSPLY
0007.04 C READ STDR 10
0007.05 * Write into File
0007.06 C WRITERSTD
0008.00 C ENDDO
0009.00 C SETON LR
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
NOTE :We are updating ‘STUD2’ so that we
define FILE TYPE as ‘U’ and FILE
ADDITION ‘A’ which helps us to add records in ‘STUD2’ . File name
must be less than or equal to 6 character only.
To move the content of ‘STUD1’ to ‘STUD2’
use Opcodes ‘MOVE’ and ‘Z-ADD’ for Character and Numeric field
respectively. And use them in program as
shown below.
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==> RPG1
FMT
FX .....FFilenameIPEAF........L..I........Device+......KExit++Entry+A....U
*************** Beginning of data *************************************
0001.00 FSTUD1
IF E K DISK
0001.01 FSTUD2
UF E K DISK A
0003.03 *
0003.05 C READ STDR 50
0003.06 C READ RSTD 20
0005.00 C *IN50 DOWEQ*OFF
0006.00 C ROLL DSPLY
0007.00 C SNAME DSPLY
0007.01 C Z-ADDROLL ROLLNO
0007.03 C MOVE SNAME NAME
0007.04 C READ STDR 50
0008.00 C ENDDO
0009.00 C SETON LR
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
Above program only moves the fields. To
write the field in ‘STUD2’ we used ‘WRITE’ opcodes.
WRITE (Write to file)
The write operation must designate a record
format name rather than a file name. If this ‘write’ operation is adding a
record to the file, which already contains records, then ‘A’ in position 66 of
File Specification for that file is required. Indicator defile in the LO entry
set on if the WRITE operation is not completed successfully.
Factor 1
|
|
Factor 2
|
File name / record format
(Mandatory)
|
Result Field
|
Data Structure (only for
program describe file)
|
HI
|
|
LO
|
Er
|
EQ
|
|
To write the content in PF use WRITE
opcodes with ‘STUD2’ record format ‘RSTD’ in Factor2 as shown below.
Columns . . . : 1
71 Edit PB01U01S/MYRPG
SEU==>
RPG1
FMT
FX .....FFilenameIPEAF........L..I........Device+......KExit++Entry+A....U
*************** Beginning of data *************************************
0001.00 FSTUD1
IF E K DISK
0001.01 FSTUD2
UF E K DISK A
0003.03 * READ FILE
0003.05 C READ STDR 50
0003.06 C READ RSTD 20
0005.00 C *IN50 DOWEQ*OFF
0006.00 C ROLL DSPLY
0007.00 C SNAME DSPLY
0007.01 C Z-ADDROLL ROLLNO
0007.03 C MOVE SNAME NAME
0007.04 C READ STDR 50
0007.05 * Write into File
0007.06 C WRITERSTD
0008.00 C
ENDDO
0009.00 C SETON LR
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat find F17=Repeat change F24=More keys
Now compile above program using option ‘14’
to create its object. This program transfers the content of STUD1 to STUD2.
After creation of object run the program using CL command ‘CALL
<filename>’ on command line to see the output. (i.e. CALL RPG1).
Every time when we call this program it
gets the record from one PF ‘STUD1’ and insert to another PF ‘STUD2’ at that
time same record gets added or append in STUD2 not to overwrite. So for
clearing the content of ‘STUD2’ before inserting the record again we have to
write small CL program which clears the Content of ‘STUD2’ and before writing
the data in that file.
Create the CL program having
Program Name : CL1
Source Type : CLP
Text : ‘Program for clearing Physical
File Member’
Columns . . . : 1
71 Edit PB01U01S/MYCLP
SEU==>
CL1
FMT
** ...+... 1 ...+... 2 ...+... 3 ...+...
4 ...+... 5 ...+... 6 ...+... 7
*************** Beginning of data
*************************************
0001.00 PGM:
0002.00 CLRPFM FILE(PB07U01O/STUD2)
0002.01 CALL
PGM(RPG1)
0003.00 ENDPGM:
****************** End of data ****************************************
F3=Exit
F4=Prompt F5=Refresh F9=Retrieve
F10=Cursor F11=Toggle
F16=Repeat
find F17=Repeat change F24=More keys
(C)
COPYRIGHT IBM CORP. 1981, 2002.
‘CLRPFM’ is the command, which clears the
content of ‘STUD2’ & calling of RPG1 helps to move the data of ‘STUD1’ to
‘STUD2’.
Compile the above program using option ‘14’
and call it from command line (i.e. CALL CL1). After compilation just check
‘STUD2’ using CL command RUNQRY *N STUD2.
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