scanning user space

Hey all,

Ok, now it's really getting thick.

I've decided to try and tackle userspaces to see if it will speed up my
monster IFS posting job.  i've got a pretty good idea what I'm doing, but
i'm fuzzy on scanning the space once i've loaded it.

see if this sounds ok so far.

 *   open IFS csv file
C                   eval      $FD = Open(sfPath:flag:mode)
 *   if open
C                   if        $FD <> *null
 *   get size of file using stat()
 *         (add a 100 bytes for safety)
c                   eval      statsize = %size(statds)
c                   alloc     statsize      p_statDS
c                   eval      $filesize = st_size + 100
c                   dealloc                 p_statDS
 *   create userspace (returns *off if error)

c                   if        CrtUsrSpc(USName:USLibr:$fileSize)
 *   retrieve userspace pointer
C                   eval      USPtr = RtvUsrSpcPtr(USName:USLibr)

C                   if        USPtr <> *null
 *   read from ifs file
C                   eval      rdlen=read($FD:USPtr:$fileSize)
...  process user space here.
c                   end
c                   end
c                   end


ok, now i have my user space, it's loaded with the entire IFS file and I
know how big it is.   It is a cr/lf record delimited csv.

I understand the concept of pointer math.  to scan the data for each
record, do I now have to define a string in my program based (at first
anyway) on USPtr, with a length of what I think the maximum record length
could be, and then scan that field for end of record to give me a beginning
and end of the data I want to process?  and then once processed, I just add
that length to my pointer (+1) to start my scan for the next record?

can that based string somehow be varying?

is there another way to scan the userspace in-line without basing a
variable to a pointer somewhere in the userspace?

does this make sense?  I don't have a problem writeing this thing based on
what I've described above, but it just seems, oh, not very flexible -
having to define a maximum record length and all.

keep in mind, i'm writing this for processing speed, not for convenience.

Oh, and one more thing:  does a userspace created in QTEMP work the same as
any other object in QTEMP?  (i.e. each job can have it's own copy of the
same named usrspc.)

thanks a bunch,

Rick