Need help in updating a dataset USING REXX

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Hi All.

I am reading a dataset line by line, pulling the record in a variable "record" and checking record for various conditions.
If record passes all conditions I am to write "record" the whole line into a new dataset...

So if i just use this variable to write data using EXECIO command it says invalid EXEXIO function.. do i always have to use STEM ?

Actualy i already wrote a bigg code which only uses variables and repeatedly reads the same file and used Say command to sedn outut to terminal.. and now trying to put the data into a pds .. putting in STEM i am scared might pull an unknown string

following is my code.

dbzTHEdinosauer · Posted: Thu Apr 29, 2010 10:16 pm

funny,
you used a PULL RECORD after the 1 record read with EXECIO
why don't you try a PUSH RECORD before the 1 record write with EXECIO

which would mean of course that this:

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Hello DBZ

ABove code that I pasted was only a sample thing I was trying. After pulling the record , i am to process the record , if it satisfies COND-1 , i am to read the next record and if next record satisfies COND-2 ... i am to write both these records into the OUT dataset.

So do you suggest I first do a pull twice as required and do push twice and then execio diskW operation

Something Like , taking length > somthing as a sample COND-1/-2

"EXECIO 1 DISKR INDD"
PULL RECORD
IF LENGTH (RECORD > 10)
DO
"EXECIO 1 DISKR INDD"
PULL RECORD
IF LENGTH (RECORD > 20)
PUSH RECORD
PUSH RECORD
"EXECIO 1 DISKW OUTDD (RECORD"
ELSE
NOP
END
ELSE
NOP

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Also so just using a variable like I had initially used in EXECIO command doesn't work ?

The data has to be in memory STACK or some kind of STEM ?

daveporcelan · Posted: Thu Apr 29, 2010 10:30 pm

The answers to these questions will help us help you:

dbzTHEdinosauer · Posted: Thu Apr 29, 2010 10:34 pm

Please,

RECORD is a variable. only one. so, if you do a

read
PULL RECORD /* populate with first read */
read
PULL RECORD /* populate with second read */

which means you have lost the first record.

if you insist on not using stem operations,
suggest that you at least use two variables,
like FIRST_RECORD and SECOND_RECORD
at least you will know which is which and
will not lose one.

if you would spend some time reading about the data stack,
you would find that you could
PUSH var2
PUSH var1

since the PUSH is LIFO.

also, suggest you look at the syntax diagram for EXECIO

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Hello DBZ
yeah too silly of me on the point u mentioned.. overlaying values.. damm

hello Dave

I have to be able to use this dataset repetetivey so in that sense i just want to append data to it always so used MOD.. inserting a *** for every fresh iteratio maybe

Number of records I scan in each file should be around 10000 and i am to scan 1700 such files... Selected records in each file should be b/w 0 -50 lines of code. and yes the pds members I would be scanning would have blank records too

I started reading REXX like 4 days back and I am do finish my code max by tomm .. REXX was my own choice else I would have ended up seacrhing each module manually .. so I guess i am too short of time to rewrite the code using STEM..

What I like to do is to move my 'good' data into an output stem valiable, then write all of them at the end with a single EXECIO. ---- thats a good choice .. How can i do that plS ?

daveporcelan · Posted: Thu Apr 29, 2010 11:03 pm

Your structure appears very complicated to me.

If it were me, based on your sample code, I would do it like this.

daveporcelan · Posted: Thu Apr 29, 2010 11:15 pm

sunn_io,

My guess is that what I provided, will not work based on your latest requirement.

It would be best if you provided your ACTUAL requirement, not a 'sample'.

A subset of 'real' data would also help.

What if the first record doesn't pass the test? Is the next record another first record, or is a second record to be discarded?

What if the first record passes the test and the second fails? Are they both to be discarded?

Do you see why showing data and real requirements would help?

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Hi Dave,

I guess trying would be a must, I'll try once more cause I think i have an idea now..
and post it back.

Thanks

daveporcelan · Posted: Fri Apr 30, 2010 12:03 am

good to hear.... let us know how it goes.....

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Hi Dave..

I followed the following algo and it works well. Essentially after satisfying my condition, moved data into an STEM and used the STEM at last to put data into a PDS file.
Just for the record, if my 1st record satisfies COND-1 and record 2 doesn't satisfies COND-2 , processing should continue from record 3 and record 1 and 2 be ignored.
Thank you.

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Hi All..
I had formatted the code in this window.. starting next line after leaving 2 spaces , after an IF or Do statement .. but after postig .. ALL IZZ SAME..
Poor me !

dick scherrer · Posted: Fri Apr 30, 2010 2:41 am

Hello,

Suggest you practice with the "Code" tag - it will do what you want

Notice your last reply that contains code. . .

Marso · Posted: Fri Apr 30, 2010 2:43 am

Here are a few remarks (based on 1st post):

Code:

member = IN
FILENAME="'"||'PRD.ME.('||MEMBER||')'||"'"

Keep your code simple. This will give the same result (i assume the extra point is just a typo):

Code:

FILENAME = "'PRD.ME("IN")'"
Code:

OUTNAME = "'PRD.ME.OUT'"

If you want "to put the data into a pds", then you should have a member name.
Code:

ADDRESS TSO
"ALLOC DA("FILENAME") F(INDD) SHR REUSE"
ADDRESS TSO
"ALLOC DA("OUTNAME") F(OUTDD) MOD REUSE"

The first ADDRESS TSO tells rexx "from now on, all commands unknown to rexx will be passed to TSO".
The second ADDRESS TSO is redundant and useless (and most likely the first one is useless too, because that's the default).
If OUTNAME is a PDS then you cannot have a MOD disposition.

Code:

DO WHILE DONE = 'NO'
"EXECIO 1 DISKR INDD"
IF RC = 0 THEN /* RECORD WAS READ */
... (your code here)
ELSE
DONE = 'YES' /* IF RC \= 0 CLOSE PROCESSING */

This is very complicated. If variable DONE is not assigned (and you didn't show us when and how you assign it) then you will do nothing.
Again, Keep It Simple. This will give the same result (but faster):

Code:

Do Forever
"EXECIO 1 DISKR INDD"
If RC <> 0 Then Leave
... (your code here)
End

No need for a DONE flag. No need for ELSE sentence.
You just have a unconditional loop, and once you've finished to read the file then you stop looping.

Code:

"EXECIO 1 DISKW OUTDD (RECORD"

Does this means you are learning rexx all by yourself without opening the rexx reference book???
Code:

ELSE
NOP

Useless. Just remove that please.
Code:

"EXECIO 0 DISKW OUTDD (FINIS"

If you take th time to close the output file, then do the same for the input file too:

Code:

"EXECIO 0 DISKR INDD (FINIS"
Quote:

putting in STEM i am scared might pull an unknown string

If you use STEM then you don't use the stack (unless you are pulling my leg). Using STEM is easier than using the stack, specially if you try to use it (the stack) both for reading and writing.

Quote:

What I like to do is to move my 'good' data into an output stem variable, then write all of them at the end with a single EXECIO. ---- thats a good choice .. How can i do that plS ?

you're lucky today, I'm in a good mood for some rexx! Here it comes:

Code:

/* Before the loop */
outlines. = '' /* empty output buffer */
outcount = 0 /* currently 0 lines in output buffer */

/* inside the loop, if the "record" is "good" */
outcount = outcount + 1
outlines.outcount = RECORD

/* once the loop is finished */
"EXECIO "outcount" DISKW OUTDD (STEM outlines. FINIS"

Seriously, it's your lucky day today. Do you know how much I usually charge for a session like this ?

superk · Posted: Fri Apr 30, 2010 2:52 am

What concerns me if I swear I've seen this almost exact same code before. I remember asking that member if he could tell me where he got that code from, which of course he never did. I hope this isn't coming from some publication or a text book.

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Hey Marso

Well, I must thank you for taking out time to correctly point out my mistakes. Appreciate it..

I take the charge part in light mode especially cause i got no personal message with an account number in it ..

And All this while I was using PDS and dataset words interchangeably. I am updating a dataset after reading a PDS member.

Thank you again.

I was bit in a hurry so manual printouts + the forum is what my domain is for now.. Next week, I'll dwell more into the manual.

Cheers
Sunny

sunny_io · New User Joined: 11 Jul 2007 Posts: 68 Location: noida

Hi superk

The code I pasted, is my own sweat .. no wonder it will smell salty

its also basic in approach as i feel. I used ELSE and NOP for every IF just like the manual says to do.. most publications avoid that in my view.

Regards
Sunny