z/OS to Linux migration - EBCDIC - ASCII compare notes

Products

PanAudit Plus Easytrieve Report Generator PAN/SQL Easytrieve Report Generator for Common Services

Issue/Introduction

How to get the same results on Linux like on z/OS when using CA Easytrieve for Linux?

Environment

Release : 11.6

Component : CA EASYTRIEVE REPORT GEN

Cause

Due to the different hexadecimal values of the EBCDIC and ASCII encoding schemes, there are sometimes different results when, for example, comparing fields.
For example, "a" is less than "A" in EBCDIC, but "a" is greater than "A" in ASCII.
Also numeric characters are less than alphabetic letters in ASCII but are greater than letters in EBCDIC.

Resolution

When using CA Easytrieve there is a way to get the same results on Linux (or other ASCII systems) like on z/OS (EBCDIC).
The solution is to use CMPUSINGALTSEQ(YES) at the PARM statement in your CA Easytrieve application (source), together with an appropriate alternate sequence table (ALTSEQ).
Alternatively set the CMALTSEQ option in the EZOPTBL options table to Y (an appropriate alternate sequence table (ALTSEQ) is required as well).

This is a CA Easytrieve for Linux source example:
...
*-------------------------------------------------------------------*
PARM CMPUSINGALTSEQ(YES)
*
* when using CMPUSINGALTSEQ(YES) you also need an EBCDIC
* alternate sequence table (for example "eztpaqtt_ebcdic.def")
* and run:
* cd /opt/CA/ezt/bin
* etaltseq -b <eztpaqtt_ebcdic.def
*
* furthermore set:
* ALTSEQ   EZTPAQTT
* in the EZOPTBL
*
DEFINE a-FIELD     S 1 A VALUE 'a'
DEFINE A-FIELD     S 1 A VALUE 'A'
*-------------------------------------------------------------------*
JOB INPUT NULL

IF A-FIELD > a-FIELD
     DISPLAY 'A GREATER a'
     DISPLAY 'expected on z/OS or when using CMPUSINGALTSEQ(YES)'
ELSE
     DISPLAY 'a GREATER A'
     DISPLAY 'expected on Linux with CMPUSINGALTSEQ(NO)'
END-IF

STOP
*-------------------------------------------------------------------*
...
When compiling and running the above example on Linux the result is:
...
A GREATER a
expected on z/OS or when using CMPUSINGALTSEQ(YES)
...
Without CMPUSINGALTSEQ, or with CMPUSINGALTSEQ(NO), the result is:
...
a GREATER A
expected on Linux with CMPUSINGALTSEQ(NO)
...
As outlined in the above source example, when using CMPUSINGALTSEQ(YES) you also need an EBCDIC alternate sequence table (for example "eztpaqtt_ebcdic.def") and run, for example:
...
cd /opt/CA/ezt/bin
etaltseq -b <eztpaqtt_ebcdic.def
...
Furthermore you need:
...
ALTSEQ   EZTPAQTT
...
in the EZOPTBL.

Here is an example - the content of "eztpaqtt_ebcdic.def":
...
//0 1 2 3     4 5 6 7     8 9 A B     C D E F
0x00010203 0x1A091A7F 0x1A1A1A0B 0x0C0D0E0F // 0
0x10111213 0x3C3D3226 0x18193F27 0x1C1D1E1F // 1
0x404F7F7B 0x5B6C507D 0x4D5D5C4E 0x6B604B61 // 2
0xF0F1F2F3 0xF4F5F6F7 0xF8F97A5E 0x4C7E6E6F // 3
0x7CC1C2C3 0xC4C5C6C7 0xC8C9D1D2 0xD3D4D5D6 // 4
0xD7D8D9E2 0xE3E4E5E6 0xE7E8E94A 0xE05A5F6D // 5
0x79818283 0x84858687 0x88899192 0x93949596 // 6
0x979899A2 0xA3A4A5A6 0xA7A8A9C0 0x6AD0A107 // 7
0x80818283 0x84858687 0x88898A8B 0x8C8D8E8F // 8
0x90919293 0x94959697 0x98999A9B 0x9C9D9E9F // 9
0xA0A1A2A3 0xA4A5A6A7 0xA8A9AAAB 0xACADAEAF // A
0xB0B1B2B3 0xB4B5B6B7 0xB8B9BABB 0xBCBDBEBF // B
0xC0C1C2C3 0xC4C5C6C7 0xC8C9CACB 0xCCCDCECF // C
0xD0D1D2D3 0xD4D5D6D7 0xD8D9DADB 0xDCDDDEDF // D
0xE0E1E2E3 0xE4E5E6E7 0xE8E9EAEB 0xECEDEEEF // E
0xF0F1F2F3 0xF4F5F6F7 0xF8F9FAFB 0xFCFDFEFF // F
//0 1 2 3     4 5 6 7     8 9 A B     C D E F
...
But, this is just an "eztpaqtt_ebcdic.def" example. Use at your own risk!
Maintaining and customizing the EZTPAQTT is in the responsibility of the CA Easytrieve administrator at your site.