Sathishmohan Selvaraj wrote:

> (1) Is it necessary that i always need a build command to create a file?

no

> Any other possibilities.

yes :-)

> (2) Ways in which i can create a file from a cobol program?
>
> (3) Enlight me on the difference between spool files, temporary files
> and permanent files and how each are created.

ah...a bit of mpe 101 :-)

one of the wonderful things about mpe is -- a file is a file is a file.  the
statement sounds simple -- but it's implication are vast.  so what's a:

- temporary file?  just a file, like any other file -- except that it's
'temporary' (yes, we can all say duh now :-).  when <whatever> (this could
be your session, your neighbor's session or a job) logs off, the file will
go away.  this feature is a wonderful thing.  consider an online,
interactive program that 100's of folks in your company use all at the same
time.  part of what this program does is pull data out of a database and
writes it to a file (for further manipulation).  how do you name this
file??  if it's a permanent file, the first person running the program will
create it....but what happens to the second (or third or....) person?  they
can't build the file because it's already there.  what to do?  what to do?
make sure the file is *temporary*!  temporary files are user-local,
user-private.  as a developer, you can safely allow users to create 100's
(1000's....) of temporary files -- with the exact same name! -- and never
have to worry about any collisions.  (yes, i know you could have some
algorithm front-ending the file's creation to generate a unique file
name....)

- a spool file?  it's still a file....but it's one that's associated with a
printer.  granted it's a 'special' file....but it's still a file.  spool
files, by default, end up in the account 'hpspool' in the 'out' group.
there are things you can do to a spool file that will control when (if ever)
it will print.  also, spool files are permanent files.

- permanent file?  it's a file that's not temporary (groan :-)  it's
'visible' to listfile (listf, to some folks) and has to be 'purge'd to get
rid of it.

i could go on and on....but perhaps the best thing would be to point you to
the fine manual:
<http://docs.hp.com/mpeix/onlinedocs/B3813-90012/B3813-90012.html>

i've always thought that file equations are one of the most powerful and
elegant features of mpe.  there are *so many* things you can do with file
equations....  study this and become elightened :-)  (and then come back and
ask more questions.  we like it :-)           - d

--
Donna Garverick     Sr. System Programmer
925-210-6631        [log in to unmask]

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