Browse Prior Art Database

Customized Code Page Mappings Through User-Defined Code Pages

IP.com Disclosure Number: IPCOM000100617D
Original Publication Date: 1990-May-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 3 page(s) / 107K

Publishing Venue

IBM

Related People

Nguyen, HH: AUTHOR [+2]

Abstract

Disclosed is a method for a user to specify the exact code page translations/mappings that are to be performed by a workstation equipped with a code page translation utility/program.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Customized Code Page Mappings Through User-Defined Code Pages

       Disclosed is a method for a user to specify the exact
code page translations/mappings that are to be performed by a
workstation equipped with a code page translation utility/program.

      User-defined code pages are the means by which this invention
provides user-definable code page mappings in a workstation equipped
with a code page translation utility/program.

      Code Page Translation Utility: A specific code page mapping is
requested when the code page translation utility is passed two code
page parameters, one being the source code page of the object (e.g.,
file or string) to be translated and the other being the target. The
code pages that can be passed to the code page translation utility
come in two varieties, those defined by the utility (utility defined)
and those defined by the user (user defined). Utility-defined code
pages generally are derived from standards (IBM or others).  The base
set of code page mappings provided by the utility are those which can
be created by passing any two of the utility-defined code pages.
User-defined code page mappings are those which are created by
passing a user-defined code page for either one or both of the code
page parameters.

      Code Pages and Code Page Mappings: A code page consists of 256
code point/character pairs. A code point is a number between 0 and
255 which, when paired with a character, represents the numeric value
assigned to that character.  When a character is common between two
code pages, the code points associated with the character are said to
map to each other.  A map of a single character between two code
pages is then defined as a pair of code points, the first
representing the code point of the character in the first (or source)
code page and the other representing the code point in the second (or
target) code page.  In the simplest sense, a mapping between two code
pages is defined as the union of all the single character mappings
that exist between the two code pages.  It is easy to see how giving
the user the ability to define his own code page(s) also gives him
the ability to define any code page mapping that is desired.

      Note that the above definition of code page mappings does not
consider the case of a character in one code page not existing in the
other code page.  This special case can be handled by the translation
utility in any way and will have no effect on the disclosed method
for user-defined mappings.  This is true since the user can always
avoid this situation by defining a code page(...