Question1:
How can you copy only 100 records in a file
which contains millions of records?
(Ans)
By
using CPYF command we can give the record copying position starting and ending
of the records. If we want to copy the records between 1000 and 1100 in the
million records we can give 1000 in the start position and 1100 in the end
position.
In
the another way by using CHGPF commands we can restrict the number of records
to be there in a file by giving number of records as 100 and increments as
0. In this case we can copy only the
first 100 records and not possible to copy from one position to another.
Question2:
How to convert a field from Uppercase to
lowercase?
(Ans)
By
using XLATE command we can convert a field from upper to loew case or vice
versa.
FDSPF001 CF
E WORKSTN
Dlower S 26A inz('abcdefghijklmnopqrstuvwxyz')
Dupper1 S 26A inz('ABCDEFGHIJKLMNOPQRSTUVWXYZ')
C *in03 doweq *off
C exfmt casecon
C 03 leave
C if *in09=*on
C upper1:lower XLATE
lowcase upper
C endif
C enddo
C seton lr
Here
lowcase and upper are the two fields in the screen and the user is entering
characters in lowcase in upper case and convert that to upper case and move it
to field upper when user press f9 key.
Question 3:
How to copy a file from as/400 system to a
local pc.
(Ans)
Do
the following to copy
ftp as/400 machine ip address
In wipro case ftp
10.200.9.80
It will ask for user name and password. Enter
your as/400 user id and password. It
will then say the user has logged in successfully.
If you want to copy a rpgle program called
load2 residing in shyamrlib library and source physical file name is shyamrile
then we have to change the current library into shyamrlib .Just type cd
shyamrlib and it will change the library. And then get shyamrile.load2 will
copy the file into c:\ in local pc. If
you want to copy from a PC to as/400 library then do the following
To do: Copy from c:\shyam\load2 to shyamrile\load2 in shyamrlib
Steps:
cd shyamrlib
put c:\shyam\load2 shyamrile.load2
will copy the file in shyam in c directory into shyamrile in
shyamrlib.
Question 4:
How will your read a 100th record in a group of
records in a file?
(Ans)
Declare
the file without K in record address type in file definition.
z-add
the position you want to retrieve. Suppose you want to retrieve 125th
records
then
z-add 125 to rrn
Do
chain based on rrn.
fworkfile1
if e disk
c z-add 2174 rrn1 4 0
c rrn1 chain workfile1 40
c seton lr
Here
we are reading the 2174th record.
Question 5:
Explain the usage of procedure in a life project
(Ans)
Here
is a procedure which will accept the character in lower case and return the
value in upper case. In java the user may enter either in lower or upper cases
and we have to convert into uppercase else the chain will fail. So we create a
procedure in our program which do this and call the procedure in our program.
Ex:
This
is the program which is calling the procedure.
DPROC1 PR
DX 10A
DA S 10A
C EVAL A='shyamsunda'
C CALLP PROC1(
C A)
c A dsply
c seton lr
The
procedure
HNOMAIN
DPROC1 PR 10A
D 10A
PPROC1 B EXPORT
DPROC1 PI 10A
DX 10A
Dlower S 26A inz('abcdefghijklmnopqrstuvwxyz’)
Dupper1 S 26A inz('ABCDEFGHIJKLMNOPQRSTUVWXYZ’)
C
lower:upper1 XLATE X X
C
RETURN X
PPROC1 E
Question 6:
How to query a record for getting the rrn value?
(Ans)
Select rrn(zphamsp) from zphamsp where code=’AE’
Here
zphamsp is the program name.
Question 7:
Is it possible to send arrays ,data structures
as a parameter to another program?
(Ans)
Yes
it is possible and we have to call in the same way a parameter is passed in the
program.
Ex:
darr1 s 2p 0 dim(10)
darr2 s 2p 0 INZ(1)
c callB 'ARR2PGM'
C PARM ARR1
C 1 DO 10
C ARR1(ARR2) DSPLY
C ADD 1 ARR2
C ENDDO
c SETON LR
called
program
DARR1 S 2P 0 DIM(10)
DI S 2P 0 INZ(1)
C *ENTRY
PLIST
C PARM ARR1
C 1 DO 10
C EVAL ARR1(I)=I
C ADD 1 I
C ENDDO
C SETON LR
Here
the array is passed as a parameter and the values after callb is 1 to 10
Question 8:
What is the difference in between CALL, CALLB,
CALLP
(Ans)
Call
is a dynamic call where the control will be transferred when the program Is
executed where as Callb and Callp are static calls.
A
module is a non executable program and it contains one or more procedures. If
you have modules without procedure then it means that it is having only one default
procedure and in case we can use CALLB. But if a module is having more than one
procedure then we can give explicitly the procedure name to be called in case
of CALLP
Out
of these three Callp is the most efficient one.
Question 9:
What is the new name for as/400?
(Ans)
Iseries
400 is the new name given to as/400 by IBM now.
Question 10:
How to see the source of copy books included in
a program while compiling or debugging?
(Ans)
While
Compiling the program give *list instead of *source which will expand all the
copy books.
Question 11:
How to retrieve the value from data area and
how to change the value of a data area?
(Ans)
ds s 10a
dg s 10a inz('i hate u')
c *dtaara define
data1 s
c *lock in s
c eval s=g
c out s
c s dsply
c seton lr
I
created a data area by using the command crtdtaara and give the length as 10a
and value as I love you
Statement
*dtaara define data1 s
*lock in s will copy
the content into a temporary variable s and now we are changing the value of s
as I hate you and now by using out command the value of the data structure will
be changed
Question 12:
How you will avoid multiple users updating the
same record?
(Ans)
While
displaying the records in the screen we will be getting the timestamp Along
with the actual data. Store this in output data structure and while updating
check weather the previous time stamp is the same timestamp before updating. If
the record is updated by another user then the time stamp will be changed and
if it does not matches then throw the error message ‘Record is already updated
by another user’ else update the records with current time stamp
Program1
Store
the time stamp and this time stamp will come as a input to the second program
Program
2
Here
wstmst1 contains the input time stamp and check this matches with the
database.If matches Update else send error message
C K1CDFL CHAIN ZPCDFLR 80
C MOVEL WSTMST1 WSTMST
C IF CDMOTS=WSTMST
C TIME CDMOTS
C UPDATE ZPCDFLR
C ELSE
C EVAL ERROR=1
c LEAVE
C ENDIF
C ENDDO
Question 13:
What will %size and %elem keywords will do?
(Ans)
%size
will display the size of the variable where as %elem will display the array
dimension.
darr1 s 3s 0 dim(1000)
c eval c=%size(arr1)
c eval d=%elem(arr1)
c c dsply
c d dsply
c seton lr
In
the above program c will be 3 and d will be 1000
Question 14:
What will you format a number by using as/400?
(Ans)
By
using Editw Keyword
For
example if you want to print 1234567890.12 as $1,234,567,890 dollars and 12
cents then the edit word must contains ‘$ ,
, , &dollars&and& ¢s.’
Here
& will be used to add a space and a blank space represents the variable. So
for printing and 12 cents we will give as &and& 12¢s. Where & represents blanks
space in edit word and actual blank space is the variable 12.
dsalary s 12p 2 inz(1234567890.12)
dedit c '$ , ,
, &dollars&and& ¢s’
damount s 40a
c eval amount=%editw(salary:edit)
c amount dsply
c seton lr
Question 15:
How you can schedule a job to run periodically?
(Ans)
We
have to create a job scheduler for running a job periodically. Here we can make
a job to run once or periodically at a given date and time. . We can create a
job scheduler by using addjobscde command.
We
can list all the job scheduler running by using the command wrkjobscde and we
can delete a job scheduler by using rmvjobscde or we can reschedule the job by
using chgjobscde.
Question 16:
How you can bind a C module with a RPG Program?
(Ans)
Create
a C module of type c
void
logit (char *t)
{
printf("'%s'\n",t);
}
And
bind this program by calling it as a module in RPG program
D
txt S 40A INZ('Hello, world !')
D
logit PR EXTPROC('logit')
dtxt * value OPTIONS(*STRING)
c CALLP logit(%TRIMR(txt))
c return
Create
program for this rpg by binding with the c module and call this program.
Question 17:
How to debug a batch job?
(Ans)
Hold
the batch job to be debuged by using wrkactjob command and having option 3. Set
the pointer in the batch program to be debuged by using strdbg and then call
the strsrvjob command and start the service program which will enter into the
debug mode. After entering into debug mode release the job that is hold before.
Question 18:
Explain briefly about Non join Logical File.
(Ans)
Logical
files can be derived from 1 to 32 physical files and so a logical file can have
a maximum of 32 Record formats.
If
a logical file is derived from single physical file without joining then it is
single record format logical file.
Single
record format logical file:
Refaccpth
is applicable for Non join logical file only and meaning is refer the access
path from the physical or the logical file in the file level entry.
PFILE
is applicable only for non join logical file in record level entry.
R RECPF2 PFILE(PF02)
K EMPNAME
Here
the employee files key will be changed from empno to empname.
Output
of this query is
No NAME ADDRESS1 ADDRESS2 CITY
STATE ZIPCODE
1
SHYAM 29,ARUNA NAGAR PUTHUR
TRICHY TN 17
2
RAMBABU 29,ARUNA NAGAR
PUTHUR TRICHY TN
17
3
SASI 53,KULALAR STREET CUMBUM TN
54
********
End of report ********
Here
runqry will select all the records in pf02.
R RECPF2 PFILE(PF02)
EMPNAME 15A
CITY 10A
K EMPNAME
Here
the attribute size of city is changed from 30 to 10 and also the key value is
changed.
The
output of this query is
EMPNAME CITY
SHYAM TRICHY
RAMBABU TRICHY
SASI CUMBUM
R RECPF2 PFILE(PF02)
EMPNAME 15A
CITY 10A
EMPNO 5S 0
K EMPNAME
O EMPNO CMP(GT 2)
The
output of this is
EMPNAME CITY empno
SHYAM TRICHY 1
RAMBABU TRICHY 2
Here
the employee number 3 is omited since it is greater than 2.
Multiple
record non join logical file will select records from 2 or more physical files
by referring to only one logical file
1)
Each record format is always associated with one or more physical file.
2)
The same PF can be used in more than one record format.
Question 19:
Explain Inner join or natural join and left
outer join.
(Ans)
Natural
join
In
case of natural join only the matching records in between the joining file will
be selected.
If
the pf of 2 files is like this
PF01
PF02
R JP1REC
R JP2REC
EMPNO 5S 0
EMPNO 5S 0
EMPNAME 20A
EMPSAL 15P 0
K EMPNO
K EMPNO
The
records in the 2 files are as follows
Empno Empname
Empno Empsal
1 shyam
1 1000000
2 sundar 2 2000000
3 rambabu
4 1000000
Then
in case of natural or inner join the records selected are
Empno Empname Empsal
1 shyam 1000000
2 sundar 2000000
where
as in Left outer join all the records from primary file and the matching
records from the secondary file will be selected.
The
output is
Empno Empname Empsal
1 shyam 1000000
2 sundar 2000000
3 rambabu 0
Note
that the salary will be defaulted to default values and the employee number 4
is not selected since this is the secondary file.
R JL1REC JFILE(JP01 JP02)
J JOIN(1
2)
JFLD(EMPNO EMPNO)
EMPNO JREF(JP01)
EMPNAME
EMPSAL
K EMPNO
Where
as in inner join we have to specify jdftval in file level entry
JDFTVAL
R JL2REC JFILE(JP02 JP01)
J JOIN(1 2)
JFLD(EMPNO EMPNO)
EMPNO JREF(JP02)
EMPNAME
EMPSAL
K EMPNO
JFILE:
It is similar to indicate that this is a Join logical file and it must have
more than 2 physical files
Join
: It indicates what are the files to be joined in this case. We can represent
the position of the files. There must be one primary file and can have more
than 1 secondary files.
JFLD
which fields we are going to join
JREF
represent the primary file reference field.
JDFTVAL
represents that it as a left outer join.
If
we are joining more than one Physical files then we can represent it as
follows.
If
the first two files are the same JP01 and JP02 and the third file to be joined
is JP05
Which
is having these fields
R JP1REC Empno address
Empno 5s 0 1 Trichy
Address
20a
2 Cumbum
K empno
Then
the result is
1 shyam 1000000 trichy
2 sundar 2000000 cumbum
which
fetches the matching record in all the three files.
JDFTVAL
R JL5REC JFILE(JP01 JP02 JP05)
J JOIN(JP01 JP02)
JFLD(EMPNO EMPNO)
J JOIN(JP02 JP05)
JFLD(EMPNO EMPNO)
EMPNO JREF(JP01)
EMPNAME 20A
EMPSAL 15P 0
ADDRESS
K EMPNO
Question 20
What will FOR opcode will do?
(Ans)
dn s 5s 0 inz(10)
di s 5s 0
* for(i=0;i<n;i++)
c for i=1 to n
c i dsply
c endfor
*
for(i=n;i<1;i--)
c for i=n downto 1
c i dsply
c endfor
*
for(i=5;i<40;i=i+10)
c for i=5 by n to 40
c i dsply
c endfor
c
c for i=5
to 40 by n
c i dsply
c endfor
c
*
for(i=5;i<40;i=i+10)
c seton lr
Question 21
What are the various stages for a job after it
is submitted?
(Ans)
Jobqueue,
Active job and OUTQ are the three stages after the job has been submitted.
Question 22
What are the difference between non join
logical files and join logical files
(Ans)
|
Non Join Logical Files
|
Join Logical Files
|
|
We
can able to insert or delete or update records using non join logical files.
|
Insertion,
updating or deletion of records is not possible in join logical files
|
|
DFU can be used to display Non join logical
files
|
DFU
is not available
|
|
1-32
record format can be specified
|
Only
one record format can be specified
|
|
Commitment
control is used
|
Commitment
control is possible
|
Question 23
Explain Self join in detail
(Ans)
In
a employee physical file there are 3 fields named empno,empname and mgrid.
Manager
is also an employee and he has an employee id in the same table with some other
as manager. We want to query the records with the fields empno,empname and
manager name. So based on the manager id we have to select the corresponding
employee id and select the employee name and move that as the manager name.
DDS of Physical File
DDS of Physical File
SEU==>
PFTEST
FMT PF
.....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++
*************** Beginning of data
*************************************
0001.00 A
R EMP
0002.00 A EMPID 5
0
0003.00 A EMPNAME 20
0004.00 A MGRID 5
0
****************** End of data
****************************************
Data
in Physical File
EMPID EMPNAME MGRID
000001
10,001 Sebi Joseph C. 50,001
000002
10,002 Purushottam 50,002
000003
10,003 Sameer Dighe 50,003
000004
10,004 Sharada Menon 50,004
000005
10,005 Saju Paul C. 50,005
000006
50,001 Shivaram Pasuvan 90,001
000007
50,002 Praveen K. Gaurav 90,002
000008
50,003 Lionel King 90,003
000009
50,004 Sam Mathew Varghese 90,004
000010
50,005 Anil Jandyam 90,005
******
******** End of report ********
FMT LF .....A..........T.Name++++++.Len++TDpB......Functions++++++++++++++++++
*************** Beginning of data
*************************************
0001.00 A
R EMP JFILE(PFTEST PFTEST)
0002.00 A
J JOIN(1 2)
0003.00 A JFLD(MGRID EMPID)
0004.00 A EMPID JREF(1)
0005.00 A EMPNAME JREF(1)
0006.00 A MANAGER RENAME(EMPNAME) JREF(2)
0007.00 COLHDG('MANAGER')
****************** End of data ****************************************
Output
of Join Logical File
Line
....+....1....+....2....+....3....+....4....+....5.
EMPID
EMPNAME MANAGER
000001
10,001 Sebi Joseph C. Shivaram Pasuvan
000002
10,002 Purushottam Praveen K. Gaurav
000003
10,003 Sameer Dighe Lionel King
000004
10,004 Sharada Menon Sam Mathew Varghese
000005
10,005 Saju Paul C. Anil Jandyam
******
******** End of report ********
Question 24:
What is a field reference file?
(Ans)
This
is a physical file which does not have any data and contains only the field
descriptions and these fields are referred in other pf by using ref and reffld.
This
is the third type of file along with PF and LF.
Question 25
What will runsqlstm will do?
(Ans)
If
we want to execute set of sql statements (only insert, update and delete and no
select is allowed) then we can write all the sql statement to be included with
the source type as sql. Then use strsqlstm to execute the program
RUNSQLSTM
SRCFILE(SHYAMRLIB/TESTSHYAM) SRCMBR(SQL1) COMMIT(*NONE)
Question 26
What is the advantage of Opnqryf over SQLRPG?
(Ans)
|
opnqryf
|
sqlrpg
|
|
Opnqryf
will come along with os/400 system and no need to have any additional package
needed to execute it.
|
We
need to have sqlrpg installed in as/400 system which involves additional cost
to the programmers
|
|
Opnqryf
is faster as compared to sqlrpg
|
It
is slower
|
|
Opnqryf
Is nothing but a dynamic logical files which will be created and the records
are queried and finally the logical files are deleted and OPNQRYF provides
that facility
|
SQLRPG
is imbedding sql statements directly within SQL Statement
|
Question 27
What is the equivalent command to setll *loval
in CL
(Ans)
POSDBF with file position as *start will set the file to the
beginning or using ovrdbf and specify the keyfield value by rrn value or by
giving *start.
Question 28
What is the difference between OPM, EPM and RPGILE?
(Ans)
|
OPM
|
EPM
|
RPGLE
|
|
Open
Program Model is the old RPG/400 system, which will not allow a program type
to call another program type.
|
Extended
program model will support PASCAL, FORTRAN and other programming concepts.
|
It
supports mixed program support in which you can combine any program with
another type of program
|
|
|
Version
is V1R2
|
Version
is V2R3
|
Question 29
What is the difference between Bind by value and Bind by
reference?
(Ans)
|
Bind
by value
|
Bind
by Reference
|
|
Here
all the modules to be bounded are physically copied into the main program
object.
|
In
this case we are binding the programs by using service programs which
contains a reference to the modules that has been called and the modules are
not physically copied into the program objects
|
|
The
program will be executed even when you delete all the modules that have been
called.
|
The
program will not executed when the bind modules are deleted.
|
|
Bind
by value is faster than bind by reference
|
It
is not as faster as bind by value
|
Question 30
How to create a service
program and what are the steps involved in this?
(Ans)
While
creating service program we can create a binder program where we can refer the
modules or procedures or even data types to be used by the program, which is
using service program. If we are having 100 procedures in a module and if you
want to specify only some procedures to be bind in the service program we can
create the binder program.
STRPGMEXP SIGNATURE('BND')
EXPORT SYMBOL('PGM1')
ENDPGMEXP
Here
there are 2 programs PGM1 and pgm
PGM1 PGM
DA S 2P 0 INZ(8)
CALLB ‘PGM1’
DB S 2P 0 INZ(8) SETON LR
DC S 2P 0
C EVAL C=A+B
C
SETON LR
Then
we create the binder program, which will give authority to only one module
named PGM1
Then
create the service program with binding program incorporated. If no binder
program is incorporated then all the modules will be taken as default
CRTSRVPGM
SRVPGM(QTEMP/SRVPGM) MODULE(QTEMP/XXXX) SRCFILE(IDCPGRRSP/SHYAMR
ILE)
SRCMBR(BND)
DSPSRVPGM
Will helps us to display the details about the service program that has been
created.
We
can also create a bind directory for a service program where we can bind all
the modules together and if we do like this then there is no need to bind all
the programs and we can compile the program straightly by using crtbndrpg even
it has more than 1 module.
CRTBNDDIR
BNDDIR(QTEMP/BNDDIR)
2)
ADDBNDDIRE BNDDIR(QTEMP/BNDDIR)
OBJ((*LIBL/SRVPGM *SRVPGM))
The type of service program that is created is *srvpgm.
Question 31
What is an activation
group?
(Ans)
Activation
group is the boundary set for similar programs. Activation group is also a
storage space in memory.
Consider
for example the following scenario
2)
CLP has a ovrdbf command and calls a
rpg program
3)
RPG program performs a read
operation and the pointer is now in the second program and now call the program
3
4)
RPG program that also do a read
operation which will read the second record since the pointer is in the second
position and then return to 2nd program
In the above situation when the control transfers from 3rd
program to the 2nd program then it will read the 3rd
record since the 2nd record is already read in program 3. But we
need to read the 2nd record according to the logic but this is not
possible in any OPM programs. But in ILE there is a solution for this problem
by giving a common activation group for 1st and 2nd
program and have a separate activation group for the 3rd program while
creating the program itself and this will avoid all the problem we faced
before.
In
some situation we want to share between 2 programs then we can give the
activation group in *job level in
which the changes in one program will be affected in another program.
Types of
activation group levels:
*new : In this
case every time you call the program an new activation group will be created
which this case will not be used mostly.
*caller: If we
don’t know the type of the program that is calling then we can specify *caller
where the activation group will be the same of the program that is calling.
Named activation group:
We can give our own named for different activation group
Question 32
What are the statements
that are affected by activation group?
(Ans)
1) OVRDBF
2) OPNQRYF
3) STRCMTCTL
4) DLTOVR
5) OPNDBF
Question 33
What are the
statements, which is not used in CLLE that is used in CLP?
(Ans)
2)
RCLRSC
which is replaced by RCLACTGRP
3)
TFRCTL
Question 34
Write a brief note on
procedures used in RPGLE
(Ans)
1)
Defining the Prototype: Prototype will specify the following things
2)
Parameter type
3)
Sequence of the parameter
4)
Return variable and its type
5)
It tells the name of the procedure
and also the type of the call.
It
will avoid all the run time problems like parameter mismatch by specifying the
prototype like this
2)
Prototype interface:
It
is like the *entry parameter where we will specify the parameters that are
received in this program.
3)
IMPORT and EXPORT
If you want to specify the procedures to be
used by the external programs then we can specify EXPORT in your procedure. If
you don’t want then leave it blank. It is similar like giving private or public
in JAVA.
4)
Global and local variables
If
you declare a variable in main procedure then it will be accessible in all its
sub procedure and this is global declaration and if you specify the declaration
in the sub procedures then it will not be accessed in other procedures or in
the main procedure.
5) RETURN
If we specify return in the sub procedure then it means that
we are returning something to the calling program. We can return a maximum of
only one variable to the calling program.
6)
Recursion
A
procedure calling to it self is known as recursion
7)
Pass by value/Pass by reference
In
case of pass by reference we are passing the address of the parameters and not
the actual value and so the changes in the called procedure will affect the
value in the calling programs. In OPM programs we are using only call by
reference and in RPGLE we have the option to pass the parameter by value by
giving the keyword VALUE
8)
CALLP/Expression
We
can call the procedure by using CALLP command if it is not having any return
type and by an expression if it returns any value
Example
EVAL
C=PROC1(A:B)
Example
program doing recursion using procedure.
Called
procedure:
H NOMAIN
DRECUR PR 3S 0
DA 2S 0
*
DB S 3S 0 INZ(1)
PRECUR B EXPORT
D
RECUR PI 3S 0
D
A 2S
0
C IF A<>1
C EVAL B =
B*A
C EVAL A = A-1
C CALLP RECUR(A)
C ENDIF
C
RETURN B
PRECUR E
*
Calling program
DVAL S 2S 0 INZ(5)
DFACT S 3S 0 INZ(1)
DRECUR PR 3S 0
DA 2S 0
C
C EVAL FACT = RECUR(VAL)
C FACT DSPLY
C SETON LR
Question 35
What is program entry
procedure (PEP) and User entry
procedure (UEP)
(Ans)
If
we are binding many modules together to form a program then we have to specify
which module has to take control first when it has been called and that module
is called as PEP for that program.
User
entry procedure is the first statement that takes the control when a program
has been called. For example in C programs main( ) will be executed first when
it has been called and like wise in RPG the statement coded in C spec will take
the control first.
Question 36
Explain about FMTDTA in
detail.
(Ans)
Here
there is a pf of the following attributes
R REC1
EMPNO 5S 0
EMPNAME 20A
ADDRESS 25A
DOB 8S 0
And
this physical file is having the following records
Empno
name address dob
1
shyam trichy 11,021,999
2
tom pune 11,122,002
3
ccc jjhhj 11,021,999
We
want to sort the file based on address in ascending order then we have to code
the format data in the following way.
IPRH and IPRF are used to add the attributes of
format data.
HFILE
025A X pf02
FNC00260050 address
FDC00010058
Here
we want to sort the physical file based on the address and the length of the
field to be sorted is 25. If we want to sort based on more than 1 field
(address,dob) then give the length as 33(25+8)
HFILE
025A X pf02
The
address position starts from 26th position to 50 and we have more
fields declare all the fields by taking IPRF Spec
FNC00260050 address
After
coding all the fields to be sorted give the total length of all the fields in
the file. Here the file pf02 has a length of 58 and we declare it as follows
FDC00010058
The
type of this program is anything even a text file. After coding the sorting
manner we have to make use of format data command to create a file that
contains the sorted record.
FMTDTA INFILE((IDCPGRRSP/PF02)) OUTFILE(QTEMP/PF02)
SRCFILE(IDCPGRRSP/SHYA
MRILE)
SRCMBR(FMT)
This
will copy the records into PF02/qtemp and the records will be sorted on
address.
Output
after sorting:
EMPNO
EMPNAME ADDRESS DOB
3
ccc jjhhj 11,021,999
2
tom pune 11,122,002
1
shyam trichy 11,021,999
Question 37
What is the difference
between FMTDTA and OPNQRYF
(Ans)
|
FMTDTA
|
OPNQRYF
|
|
It
will sort the records sequentially based on the position of the record.
|
It
will sort the records based on the field values.
|
|
If
any changes in the attribute size of a pf then we have to change the program
specification also
|
If
there is any change in the attribute size it will not affect the program
specification also.
|
|
FMTDTA
is bit faster in process than opnqryf.
|
OPNQRYF
is slower as compare to FMTDTA if we are processing millions of records.
|
Question 38
How you can import and
export a data type between 2 programs
(Ans)
If
you are using an export statement when declaring a variable then the data type
can be imported in any modules that is bind either by value or by reference. So
in this case we can pass values in between modules instead of using plist and
*entry.
Program 1
DDD
S 2S 0 EXPORT
INZ(1)
C
CALLB 'EXP01'
C DD DSPLY
C
SETON LR
Program 2
ddd
s 2s 0 import
c eval
dd=6
c
seton lr
In
the above example the value of the variable DD will be passed to the next
program and it value is changed in the second program without using *entry and
plist
Question 39
How you can use
pointers in RPGLE
(Ans)
Pointer is concept of referring the
variable in the basis of address. We can make many variables or data structures
that refer the same address space by using this pointer.
dbase_address s *
ddsname1 ds based(base_address)
dfirname 10a
dlasname 10a
ddsname2 ds 30
c eval base_address=%addr(dsname2)
c eval dsname2='shyam sundar'
c
firname dsply
c
lasname dsply
c seton lr
Here
in the above example we declare the pointer base_address and we make the
datastructure dsname1 assigning to that pointer. We declare another data
structure and till now the memory is not allocated to the pointer. Then by
using the command
c eval base_address=%addr(dsname2)
we
are allocating the address space to the pointer and since the data structure
dsname1 is also referring this any change to dsname2 will affect dsname1. So
assign some values to dsname2 and we can see the values in dsname1 also. Here
the firname and lasname will print as shyam and sundar respectively.
Question 40
Discuss about option
keyword in detail
(Ans)
options(*varsize) : It is similar to declaring the variable as
varchar instead of char. So if we declare a variable with size 100 and if you
initialize with shyam then it will allocate only 5 spaces.
Options(*nopass):
This means that this parameter can be passed or even omitted
Options(*omit):
We can give both *nopass and *omit for a single variable.
Options(*string):
If we are passing string to the called program and if it is expecting the
pointer then in such case we can give this option.
Please
refer the question 16 for further clarification
Question 41
Explain EXTPGM in
detail
(Ans)
If
we want to call a procedure dynamically then we can make use of this command
d
prot1 pr extpgm('qcmdexc')
d cmdstr 1000 options(*varsize)
D CONST
d cmdlen 15s 5
D CONST
d const1 3 options(*nopass)
D CONST
D Cmds C 'DSPWSUSR'
c callp prot1(cmds:%len(cmds))
c seton lr
In
the above program example we are passing 3 variables to qcmdexc command for
listing cl command.
Question 42
Explain O Spec and use
of EXCEPT Opcode in detail
(Ans)
O-Spec
is used for printing records and except opcode is equal to writing the record format
name in case of RLU.
We
are printing all the records in the physical file pf02 whose has empno,name and
address as the fields by using O-spec and except opcode.
fpf02 if
e disk
fqsysprt
o f
132 printer
dss s 20a inz('--------------------')
c*
*loval setll rec1
c read rec1 80
c except header
c
*in80 doweq *off
c except detail
C read rec1 80
c enddo
c seton lr
*
oqsysprt
e header
o ss 20
o ss 40
oqsysprt
e detail
o empno 5
o empname 25
o address 45
****************** End of data
*************************
The
output of the spooled file is
----------------------------------------
00001shyam trichy
00002tom pune
00003ccc jjhhj
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