EZPATCH: disk patch utility

Description

Allows any character of any file to be modified. Works in either hexadecimal or character mode.

Categories

Conversion
System Operation

Related files

EZPATCH: Object file for program.

DISPLAY: The display option links to the Wang DISPLAY utility, using BLOCK mode.

User Instructions

Disk file modification ("patch") utility for any type of file. Changes can be entered in hex or character formats.

The first EZPATCH screen prompts for the file name and location, whether updates are to be allowed, and whether to list the changes (if allowed). After entering this data, the user is presented with a display that simultaneously shows nine lines of 16 characters each from the file, along with their hexadecimal equivalents. The user can roll the display up or down from this position, or position to exact locations in the file by entering the BLOCK and POSITION in decimal numbers) or the BASEADDR and OFFSET (hexadecimal numbers).

Data in the file can be edited at any time by positioning the data to be modified in the center line and pressing PF(03). Changes can be entered either in the hexadecimal columns on the left or the character lines to the right. When the changes have been made, exit edit mode by pressing (RETURN) or press PF(16) to exit without saving the changes.

After all changes are made, press PF(16) to exit to the EOJ screen. From the EOJ screen, you may edit another file (PF(01)) or exit EZPATCH.

WARNING: like all patch utilities, EZPATCH allows changes to a file that may render it useless for all purposes. Always be sure that you have adequate backup before attempting to patch any file.

Programmer Instructions

While file patching is inherently an interactive process, occasions do arise where specific areas in a file might be routinely changed. For these purposes, EZPATCH offers GETPARM screens for almost all functions.

If a procedure is used for control of EZPATCH, the File Data screen is changed radically (see example). The first use of the DATA screen must specify the position in the file. Subsequent DATA screens may use the PF keys as they are used manually. Exiting from the DATA screen (PF(16)) also ends the program, rather than allowing another file to be processed through the EOJ screen.

INPUT       Press (RETURN) to continue, PF(16) to exit the
            program.

  FILE      (blank)     The location of the file to be
  LIBRARY   [inlib]     processed.
  VOLUME    [invol]

  UPDATE    YES         Set to NO to use for display only (no
                        modification).

  LIST      NO          Set to YES to get a listing of the
                        lines modified during the session.

  LINES     055         Lines per page of listing (if
                        selected).

DATA        Optional; appears under program or procedure
            control only.

            First use (set position).  One of the following
            two methods must be used to set the position of
            the file.  Enter data and press (RETURN) to
            continue or PF(16) to exit program.

  BLOCK     (blank)     Decimal position of characters in the
  POSITION  (blank)     file.

  BASEADDR  (blank)     Hexadecimal location of characters in
  OFFSET    (blank)     the file.

DATA        Optional; appears under program or procedure
            control only.

            DISPLAY mode.  The data lines are visible but
            cannot be modified.  All PF keys are enabled.
            Press PF(03) to enter MODIFY mode, PF(04) to see
            previous page, PF(05) to see the next page,
            PF(06) to move down one line, PF(07) to move up
            one line, PF(14) to enter DISPLAY (BLOCK mode),
            or PF(16) to exit program.

DATA        Optional; appears under program or procedure
            control only.

            MODIFY mode.  The DATA field is open for
            modification.  Most other PF keys are disabled.
            Press PF(16) to return to DISPLAY mode without
            saving changes.

  DATA      (varies)    A 32-character hexadecimal
                        representation of the data on that
                        line.  Changes may only be made using
                        hexadecimal characters.  If blanks
                        are entered they are interpreted as
                        "no change."

Example of use

EZPATCH can be used to repair files damaged by system crashes, make changes to object files without recompiling, and many other uses. One use might be to patch the defaults in system utilities (DISPLAY, EDITOR, etc.) to more closely follow your preferences. Caution: always retain extra copies of any file to be patched.

Comments

With the ability to patch any type of file with either hexadecimal or character entries, EZPATCH is easily the most powerful utility of its type. Be sure that only qualified users are allowed access to it.