Re: printf and locale

[Daniel J Sebald]

On 02/23/2013 01:48 PM, Rik wrote:
> 2/23/13
>
> All,
>
> There's a new bug report on the tracker where the locale of the user is
> causing gnuplot to choke (https://savannah.gnu.org/bugs/index.php?38372).
> The problem is on the development branch where printf has been patched to
> respond to locale and is now emitting lines like "linewidth 0,500000"
> instead of "linewidth 0.500000" which gnuplot expects.  There is already a
> bug report about the locale patch causing an error in 'make check' if the
> fr_FR locale is not installed.  I wonder if we haven't moved too quickly to
> add locale support without considering all of the necessary changes.  It
> seems to me that we either need to seriously examine the code base for all
> possibe locale-aware constructs, or back off until we have enough time and
> manpower to tackle this project.

It's a tricky problem.  To convert 0,50000 back to 0.50000 is difficult 
after the fact because it requires context; so that's not a good way to 
go.  That means

1) At the point of translating the float machine representation into 
ASCII there needs to be a test of the locale flag and conditional tests 
on what the output destination is.

or

2) Just before displaying to the screen a routine could scan the output 
line and convert and decimal points to commas.

#1 is bad in the sense that it runs against the paradigm of generating 
output which can be redirected.  #2 is sort of clumsy or may not cover 
all basis (i.e., is the command line/pager output the only place where 
decimal-point should be translated to a comma-point?).

Dan