Re: Where to find out more about C's functions like cvtch and cvthc

[Keith Carpenter <carpcon@xxxxxxx>]

If it's documentation you want try the old site...
http://publib.boulder.ibm.com/pubs/html/as400/online/homeeng1.htm

These functions are documenteed in this book...
ILE C/C++ MI Library Reference: SC09-2418
http://publib.boulder.ibm.com/pubs/pdfs/as400/V3R7PDF/qbjadr00.pdf


Barbara's use of short & long helps to avoid IBM's confusing usage of 
hex & char.  To some of us, Hex means a hexidecimal representation (ie. 
0-9,A-F) but with these commands Hex means binary and Char means hex 
characters.   Bin & Hex would have been a better choice.


Keith



Dave Murvin wrote:
> I have been looking through the archives for information on converting 
> characters to hex.  I found several sample prototypes such as the 
> following from Barbara Morris:
>
>     D cvthex1To2       Pr                  Extproc('cvthc')
>      D  longReceiver                   *   Value
>      D  shortSource                    *   Value
>      D  receiverBytes                10i 0 Value
>
>      D cvthex2To1       Pr                  Extproc('cvtch')
>      D  shortReceiver                  *   Value
>      D  longSource                     *   Value
>      D  sourceBytes                  10i 0 Value
>
> What I have not been able to find is where these procedures are 
> documented so I can figure out how to use this type of procedure (and 
> other C function procedures) myself.  When I search the Info Center for 
> the Convert Character to Hex procedure, what I get is the following, 
> which does not look like the prototypes to me.
>
>
> Convert Character to Hex (CVTCH)
>
>
> Op Code (Hex) Operand 1 Operand 2
>
> 1082 Receiver Source
>
> Operand 1: Character variable scalar.
>
> Operand 2: Character variable scalar.
>
> Description:   Each character (8-bit value) of the string value in the 
> source operand is converted to a hex digit (4-bit value) and placed in 
> the receiver operand. The source operand characters must relate to valid 
> hex digits or a conversion  (hex 0C01) exception is signaled.
> Characters Hex Digits
> Hex F0-hex F9 Hex 0-hex 9
> Hex C1-hex C6 Hex A-hex F
> The operation begins with the two operands left-adjusted and proceeds 
> left to right until all the hex digits of the receiver operand have been 
> filled. If the source operand is too small, it is logically padded on 
> the right with zero characters (hex F0). If the source operand is too 
> large, a length conformance  (hex 0C08) exception or an invalid operand 
> length  (hex 2A0A) exception is signaled.
>
> Substring operand references that allow for a null substring reference 
> (a length value of zero) may be specified for operands 1 and 2. The 
> effect of specifying a null substring reference for the source is that 
> the bytes of the receiver are each set with a value of hex 00. The 
> effect of specifying a null substring reference for the receiver is that 
> no result is set.
>
> Is there a manual on this?  If so, can someone let me know where to find 
> it?  I have looked at the ILE C/C++ run time library manual and these 
> functions do not appear to be there.
>
> Thanks for the help.
>
>
> Dave Murvin
> DRM Enterprises, Inc.