Re: [ gnuplot-Patches-992149 ] String variables revisited

[Ethan M. <merritt@u.washington.edu>]

I'm moving this to the mailing list, because I hate the format
of Email sent via the SourceForge patch site.

On Friday 16 July 2004 02:22 am, Harald Harders wrote:
> Ethan Merritt wrote in the summary for patchset #992149
>
> internal.c internal.h
> =================
> 1) Define a new internal function f_sprintf(). This is
> visible to the user as a new built-in function
> sprintf("fmt",...), which is the first, and so far the
> only, function in gnuplot that accepts string variables
> as arguments.

> I think this patch looks like a good thing, but I really
> don't like the name `sprintf'. It really sounds like a c
> programmer had no good idea how to call it.

I was not clear enough.  This *is* the C language
sprintf routine [*].  The gnuplot code just collects the 
variables and the format and passes them along to
the C library. The documentation will refer users to
"man sprintf" or to any C language manual. 

> set xlabel string(" %d %d %d", 1,2,3)
> 
> The sprintf (or string) command should really understand all
> gnuplot formats (%t, %T, %l, %L, etc.).

For me, part of the rationale for this work is that the gnuplot
formats are limiting.  If there is some particular format that
you cannot produce using a C language printf() variant, then
we can provide a separate routine for that.  Or there could
be a second formatting function that specifically uses only
the non-C gnuplot format conversion specifiers.

    mystring = string("Format using %T %L etc", var1, var2)
    set title sprint("C Format with embedded %s", mystring)


[*] Actually, it's snprintf() because otherwise there is little
hope of preventing all buffer overflows.  As I recall, there is
an issue with some platforms not providing snprint().  My
inclination is to say that string variables are not supported
on such platforms.

-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195