Re: Engineering Units

[mooney@aps.anl.gov (Tim Mooney)]

re...
> ...problem with get_units.
> ...
> What we can do for now is to define a symbol MAX_UNITS_SIZE in dbDefs.h
> and change all record support modules and ascii files to use this symbol.
> Then when we go to next major EPICS release number we can just change
> MAX_UNITS_SIZE and have everything automatically support units strings
> of 16 characters.
> 
> Comments?

I think dbGet() should guarantee CA clients a null-terminated string by
writing a null into the last available element of the units-string
space.  If we do this, we don't need to patch any existing code (but
we do lose one character of units information).

Defining MAX_UNITS_SIZE, and patching what record-support code we can
find, will not guarantee a null-terminated string.  Eventually, some CA
client will crash in response to user input, after working fine for
months.

Tim Mooney