Jason wrote :

>> Whoaaa Tad!
>>  Time to start the Obfuscated CI Contest!

Hi Jason,

I didnt really intend to start any contest, and perhaps I should have
elaborated the point of my post, which was purely educational
rather than obfuscational.
Since this type of thread often ends up being educational to the
less experienced members of the list, I thought I should contribute.

While the logic of your routine is Ok, the efficiency in terms of CPU
is rather low, conservatively I'd say about 20:1 compared with the
version I offered and a lot more if the two input files were variable
length type.

This of course is not important for a one-off, or for a low volume job
such as this, and maybe of no importance most of the time,
but these bits of code have a habit of being 'cloned' and
adapted for slightly different tasks, and then find their way into parts
of jobs on production systems, becoming part of 'slow' jobs etc,
and have their own way of eventually generating havoc with
system performance.

And even worse, a 'newbie' to the HP3000 may adopt the technique,
and end up with a bad impression of the performance capability of
our favourite machine and operating system.

A quick analysis shows that EACH iteration of the loop inflicts
7 file opens, 7 closes, 4 reads, and 3 writes.
(If the input files were variable length, then the number of reads performed
by the print commands  would be  about n(n+1)  where n is the number of
records in file1 , and this adds up to over 60000 reads when the number
of records is 25. This is because print must sequentially read from record 1
in order to locate a given record number as passed by the start= parameter)

For example the first print statement, will open file1, open $newpass,
locate record on file1, write to $newpass, close file1, and close $newpass.
By comparison, the CNV125CF version will open file1 & 2  & 3 once only,
close once only, and only issue 1 read and 1 write per input record.

I think the CI is an extremely powerful and useful tool considering the
small number of functions that it offers, and the relatively low learning-curve
it requires. As with any tool like this, there are good ways of using it and
even better ways, and it doesnt cost a lot of effort to adopt better ways
where possible.

Cheers,

Tad.

btw,  you should be aware of a common pitfall when using print on a task like
this.
When you print a record to $newpass, you are creating a variable length  record
whose length may be truncated by the number of trailing blanks. So when you
input from $oldpass, the receiving string variables (rec1 & rec2) may not have
the length you expect, and their concatenation wont be what you want either.

>purge newfile
>purge newfile,temp
>file newfile;rec=-125,,f,ascii;disc=250
>setvar i, 1
>while i<=250
>  print file1;start=!i;end=!i >$newpass
>   input rec1 <$oldpass
>   print file2;start=!i;end=!i >$newpass
>   input rec2 <$oldpass
>   echo ![rec1]![rec2] >>*newfile
>   setvar i, i+1
>endwhile
>save *newfile


> Another CI version ,
> (slightly quicker runtime, though limited by memory
> available for CI variables).
>
> file FILEC;rec=-125,10,f,ascii
> xeq CNV125CF FILEB < FILEA > *FILEC
>
> Command file CNV125CF :-
>
> parm fileb=FILEB
> print !hpfile;start=-4 > tempcf
> xeq tempcf.!hpgroup < !fileb
> setvar n finfo(hpstdin,"eof")
> while setvar(n,n-1)>=0
>    echo ![input()+rec!n]
> endwhile
> return
> setvar n finfo(hpstdin,"eof")
> while setvar(n,n-1)>=0
>    setvar rec!n  input()
> endwhile





[log in to unmask] on 16/06/99 12:24:19

Please respond to [log in to unmask]

To:   [log in to unmask]
cc:    (bcc: Tad BOCHAN/Securities_Services/FR/PARIBAS)
Subject:  Re: File manipulation





Cheers,
Jason.

P.S. I like the way all those little bits of Korn/C Shell are gradually
creeping into the CI! Hopefully we'll get some nice piping soon.

[log in to unmask] wrote:
>
<snip>
>
> Another CI version ,
> (slightly quicker runtime, though limited by memory
> available for CI variables).
>
> file FILEC;rec=-125,10,f,ascii
> xeq CNV125CF FILEB < FILEA > *FILEC
>
> Command file CNV125CF :-
>
> parm fileb=FILEB
> print !hpfile;start=-4 > tempcf
> xeq tempcf.!hpgroup < !fileb
> setvar n finfo(hpstdin,"eof")
> while setvar(n,n-1)>=0
>    echo ![input()+rec!n]
> endwhile
> return
> setvar n finfo(hpstdin,"eof")
> while setvar(n,n-1)>=0
>    setvar rec!n  input()
> endwhile
>
<snip>
>
--
----------------------------------------------------
Please note: I will be leaving HP on 25/06/1999

As a result, all work requests should be directed to
the Help Desk and not directly to my email address.

Personal email can be sent to me at [log in to unmask]
----------------------------------------------------








-----------------------------------------------------------------------------
This message is confidential; its contents do not constitute a
commitment by Paribas except where provided for in a written agreement
between you and Paribas. Any unauthorised disclosure, use or
dissemination, either whole or partial, is prohibited. If you are not
the intended recipient of the message, please notify the sender
immediately.

Ce message est confidentiel ; son contenu ne représente en aucun cas un
engagement de la part de Paribas sous réserve de tout accord conclu par
écrit entre vous et Paribas. Toute publication, utilisation ou
diffusion, même partielle, doit être autorisée préalablement. Si vous
n'êtes pas destinataire de ce message, merci d'en avertir immédiatement
l'expéditeur.