OR OR TWO VARIABLES TOGETHER TAACLPE |
The OR command allows you to take two variables and OR them together
in an 'exclusive OR' and returns a variable with the ORed bits.
This command is of value when attempting to mask certain data or
other general use functions for an exclusive OR.
An exclusive OR is defined as:
- If both bits are on, the resulting bit is off
- If both bits are off, the resulting bit is off
- If one bit is on and the other off, the resulting bit is on
An exclusive OR function has the interesting property of allowing a
field to be masked and then unmasked by ORing back the same value
that was used to mask the field. Multiple fields can be ORed
together and the original result retrieved by repeating the same set
of OR functions. This is essentially the same technique used by the
system for the checksum function of DASD recovery.
Command parameters *CMD
------------------
INPUT1 The first variable to be ORed. It must be a
character variable of length 256. The value must be
left justified.
INPUT2 The second variable to be ORed. It must be a
character variable of length 256. The value must be
left justified.
OUTPUT The output variable which contains the result of the
OR command. It must be a character variable of
length 256.
LEN The length of the fields to be ORed. This must be a
decimal variable of LEN(3 0). There is a
performance advantage to only OR the number of
characters required.
The processing program can be called directly instead of using the
command. The parameter list is the same as that on the command.
The command is written so the processing program is not ended when it
is invoked (i.e. LR is not set on when the command completes). This
allows faster performance when the command is used multiple times in
succession. When you are finished with the command, you should
either use the FREE operation within RPG or the RCLRSC command to get
rid of the program's storage.
Restrictions
------------
None.
Prerequisites
-------------
None.
Implementation
--------------
None, the tool is ready to use.
Objects used by the tool
------------------------
Object Type Attribute Src member Src file
------ ----- --------- ---------- -----------
OR *CMD TAACLPE QATTCMD
TAACLPER *PGM RPG TAACLPER QATTRPG
Note that no CL program exists. The RPG program is the CPP.
|
Added to TAA Productivity tools April 1, 1995