of GC2C-1819-2 As Updated April 1, 1981 by TNL GN25-0826
The file, SAMPLE AUXLIST may look like the following: FIKLOOP The files: SAMPLE TEST1 SAMPLE BYPASS all UPDATE control statements (INSERT, DELETE, and so on) that
are to be apolied to the file SAMOLE ASSEMBLE. As with control file
processing, the updates are applied from the bottom of the AUI file, so
that the updates in SAMPLE BYPASS are applied first, then the updates in SAMPLE FIXLOOP, and so on. For an illustration of a set of update
files, see Figure 23. Since the updatinq scheme uses only filetypes to uniquely identify
update files, it is possible to use the same control file to update
different source input files. For example, usinq the control file REPORT :NTFL shown in Figure 23, you issue the command:
update fica pliopt a report cntrl (ctl
The command begins searchinq for updates to apply to FI:A PLIOPT, based on the entries in REPORT CNTRL: it searches for FICA AUXFIX, which
may contain entries pointinq to update files; then it searches for FICA UPDTREP1, and so on.
As as all updates and auxiliary files associated with a source
file have the same filename as the source file, the updates are uniquely
identifiable, so the same control file can be used to update various
source VM/370 takes advantage of this capability in its own procedures. By maintaining strict naminq conventions, updates
to CP and modules are easily controlled and identified.
A control file may point to many AUX files in addition to many UPDT files. You can modify a control file you want to control which
updates are applied to a program, or you may have several control files,
and the name of the control file you want to use on the UPDATE command line. There is a lot of flexibility in the UPDATE command
processing; you can implement procedures and conventions for your
individlal applications.
PREFERRED LEVEL UPDATING: There may exist more than one version of an update;-each-applicable--to different versions of the same module. For
example, you may need one version of an update for an unmodified base
source nodule, and another version of that update if that module has
been modified bv a proqram product. The AUX file that will be used to
update a particular module must then be selected based on Whether or not
a program product modifies that module. The AUX files listing the
updates applicable to modules modified by a program product are called
"preferred AUX files" because they must be used if they exist rather
than the mutually exclusive updates applicable to unmodified modules. Using this preferred AUX file concept, every module in a component can
be assembled using the one CNTRL file applicable to a user's
confiquration.
A sinqle file entry in a CNTRL file can specify than one
filetype. The first filetype indicates a file that UPDATE uses only on
one condition: the files that the second and subsequent filetypes
indicate do not exist. If they do exist, this AUX file entry is ignored
and no updatinq is done. The files that the second and subsequent 260 VM/370 User's Guide

filetypes indicate are perferred because, if they exist, UPDATE does net
use the file that the first filetype indicates. Usually, the preferred
files appear later in the CNTRL file in a format that causes them to be
used for updating. UPDATE scans each eNTRL file entry until a preferred filetype is
found, until there are no more filetypes on the entry, or until a
comment is found. (A character string that is less than four or more than eight characters is assumed to be a comment.) REPORT UPDTPROC REPORT AUXLlST REPORT CNTRL
TEXT MACS UP2 UPDTPROC LIST AUXLlST
UP1 UPDTREP1
TEXT AUXFIX update report assemble a (etl REPORT FIXIN REPORT FIXOUT W
/I. ..
./R .. .
./D .. . UPDATING 'REPORT ASSEMBLE A1' WITH 'REPORT RTNA A1'. UPDATING WITH 'REPORT RTNB A1'. UPDATING WITH 'REPORT UPDTREP1 A1'. UPDATING WITH 'REPORT FIXOUT A1'. UPDATING WITH 'REPORT FIXIN A1'. UPDATING WITH 'REPORT UPDTPROC A1'.
R;
Figure 23. An Update with a Control File REPORT RTNA (: W
I!. ..
./R .. .
./D .. . REPORT AUXFIX REPORT RTNB
section 13. Programming for the C8S Environment 261