1 /ABSOLUTE
Patches a file at absolute virtual addresses. This is the
default for Alpha and Integrity server systems. The /ABSOLUTE
function allows a user to patch any file (not just image files)
at absolute virtual addresses relative to the beginning of the
file. This feature allows replacement of existing data with new
data of the same length. If the data is smaller than that of
the original data, PATCH uses the appropriate fill character for
the mode in use. For example, if the current mode is instruction
mode, a NOP is used for fill; if it is data (numeric or ASCII)
mode, a NULL is used for fill. Any PATCH operation that results
in a data replacement longer than the length of the original
data generates an error message and terminates the command in
progress; either the PATCH or DCL prompt is then displayed,
whichever is appropriate.
Also, note that there is no default patch area, and none will be
created, because of the tendency to corrupt a file. Patch area is
meaningless in other than an image file.
If you patch a file in absolute mode, remember that there are no
symbols available to assist you in locating data locations. You
must exercise great care to ascertain that the correct locations
are modified.
Most PATCH commands will work in their normal fashion. However,
only REPLACE and DEPOSIT should be used for write operations;
other commands are acceptable for read operations. Commands that
attempt to expand the file, such as ALIGN and INSERT, should
be avoided because they will probably corrupt the file. (These
commands will be trapped by PATCH and an error message will be
issued indicating that the replacement data must not exceed the
length of the original data.)
File attributes are propagated from the original input file to
the output file. These include ALQ, TYPE, MRS, RAT, RFM, and RAC.
2 /JOURNAL
/JOURNAL[=filespec]
Indicates an alternate journal file specification. By default,
PATCH creates a journal file with a file specification that
consists of the current defaults. Use the /JOURNAL qualifier when
you want to specify an alternate file specification. If you omit
fields in the file specification, PATCH supplies the following
default values:
Filespec Field Default Value
device and directory defaults of current process
file name name of input image file
file type JNL
version 1
Subsequent PATCH sessions append information to the journal file,
rather than create a new version of this file.
The asterisk (*) and the percent sign (%) wildcard characters are
not allowed in the file specification.
3 /NEW_VERSION
/NEW_VERSION (default)
/NONEW_VERSION
Controls whether a new version of the patched file is created
or the contents of the existing file are modified in place. The
/NEW_VERSION qualifier is used in conjunction with the /ABSOLUTE
qualifier to control whether a new version of the patched file
is created or the contents of the existing file are modified
in place. /NEW_VERSION is the default. If /NONEW_VERSION is
selected, the PATCH command UPDATE will act as a checkpoint
operation, that is, all modifications made to the file are
written back to the file instead of waiting until image exit.
If /ABSOLUTE is not specified with /NONEW_VERSION, /NONEW_VERSION
is ignored, that is, a new version of the file will be created.
/NONEW_VERSION will need to be used when patching large data
files when there is not enough disk space to create a new version
of the patched file.
NOTE
If /NEW_VERSION is specified, the file will be overwritten.
No attempt on the part of the user, including pressing
Ctrl/Y, will prevent this result. Therefore, you should
have a back up copy of the file before making any attempt to
patch it.
PATCH will always issue an informational message at image
exit, indicating that the file is being overwritten.
4 /OUTPUT
/OUTPUT[=filespec]
Indicates the output image file specification. By default, PATCH
creates an output file with a file specification that consists of
the current defaults. Use the /OUTPUT qualifier when you want to
specify an alternate file specification.
If you omit fields in the file specification, PATCH supplies the
following default values:
Field Default Value
device and directory defaults of current process
file name name of input image file
file type .EXE
version one greater than the most recent copy
of the input image file
The output image file is created only when you issue the PATCH
command UPDATE at the end of the PATCH session. You can issue
multiple UPDATE commands in a single session. The first UPDATE
command creates the output image file; subsequent UPDATE commands
overwrite this file.
The asterisk (*) and the percent sign (%) wildcard characters
are not allowed in the file specification.
5 /VOLUME
/VOLUME[=n]
Requests that the output file be placed on a specified relative
volume number of a multivolume set. If you specify /VOLUME
without a number, the number defaults to the relative volume
number of the input image file.
If the /VOLUME qualifier is not specified, the file is placed in
an arbitrary position within the multivolume set.