Valid Values for a field should be A-Z or 0-9

suryamtechcse · New User Joined: 28 Apr 2006 Posts: 9 Location: Chennai

Hi,

I am in need to write an assembler code:

I want to give valid values for a field called ACTATTR.

The valid values should be only A-Z or 0-9.

Robert Sample · Posted: Fri Jan 08, 2010 9:53 pm

Probably the fastest way would be to use the TRT instruction. Googling assembler trt instruction returns 175,000 hits with plenty of examples on how to use it.

suryamtechcse · New User Joined: 28 Apr 2006 Posts: 9 Location: Chennai

Hi Robert,

I am a beginner in Assembler. Could you please provide me exact code?

Thanks

Robert Sample · Posted: Fri Jan 08, 2010 10:22 pm

This is a help forum, not a DO-YOUR-JOB-FOR-YOU forum. Most of the people who monitor this forum are paid for their professional work product (such as assembler code). Unless you're willing to pay the appropriate amount for professional assistance (rates of USD 1000 per day are fairly typical), please do not ask for code. If you code it up on your own and have trouble, there's plenty of people willing to help you fix it. But unless you show some initiative by coding on your own, you're probably not going to see much support here.

You are expected to be able to research things, read manuals, and figure out things on your own.

Ronald Burr · Posted: Fri Jan 08, 2010 10:51 pm

A warning is in order here - MANY have erred in thinking that all values between 'A' and 'Z' ( inclusive ) are alphabetic. In fact, they are NOT. In EBCDIC, the letter 'A' is hex 'C1' (x'C1') and the letter 'Z' is hex 'E9' (x'E9'). But between x'C1' and x'E9' there are values ( i.e. x'CA', x'CB', x'CC', x'CD', x'CE', x'CF', x'D0', x'DA', x'DB', x'DC', x'DE', x'DF', x'E0', and x'E1' ) which are NOT alphabetic. Do NOT neglect to account for these if you test individual bytes to determine if they are "alphabetic".

Bill O'Boyle · Posted: Fri Jan 08, 2010 11:07 pm

Yes, you must heed this warning and this is why a TRT table is your best choice for validating this data.

TRT's are issued (under the covers) by COBOL on a regular basis, such as -

IF field IS NUMERIC

IF field IS ALPHABETIC-UPPER AND field IS NOT = SPACE

The above tests will check field for 0-9 and A-Z characters.

To generate the Assembler expansion of a COBOL program which issue these tests, compile the program using the compile options LIST,NOOFFSET (normal default is NOLIST, OFFSET).

Bill

Ronald Burr · Posted: Fri Jan 08, 2010 11:27 pm

One additional caution is now indicated.

It is never a good idea to test a ONE-BYTE field to see if it is NUMERIC or ALPHABETIC.

Why? Well, because if the value is x'C1' it will qualify as BOTH. That is, the value x'C1' is both a valid (signed) number ( value +1 ) AND a valid alphabetic character ( letter 'A' ).
To test a 1-byte field, either test the actual hex representation in accordance with your requirements, or move it to the last byte of a larger field that has been pre-filled with valid values (according to your requirements), and then test that larger field.

PeterHolland · Posted: Sat Jan 09, 2010 12:34 pm

Thats true Ronald, but i guess the TS is talking about characters, not the numeric values of 0-9, e.g. x'F0' - x'F9'.
But nevertheless TRT would do the job.