Re: string function: definition of a function

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

On Tuesday 03 February 2009 14:39:43 Petr Mikulik wrote:
> > Gnuplot's strstrt() function is just a wrapper for the C library routine strstr().
> > In C you could do:
> > 
> >     char *piece = "/some/long/path/name";
> >     char *end;
> > 
> >     while (end = strstr( piece, "/" ))
> >     do    {piece = end+1;}
> > 
> > Unfortunately, gnuplot doesn't support while/do so I think you are out of luck.
> 
> We can add new function strstrtrev("piece", "/") that would return the last 
> occurence of the substring.
> 
> Would it be useful to have function for handling file names
> 	strfileparts('/home/me/bla.dat',n)
> which would return path (for n=1), name (n=2) and extension (n=3)?

These sound very specialized.  Why do we need such file-oriented string
operations, that even the standard C library does not support?

I think I'd rather go ahead and add support for a 'while' statement.
It would be limited to a single line, just as the current 'if' statement,
but it should be possible to do. 

> That would be quite handy especially in the "plot for" loop.

Could you give an example showing why this would be useful?

-- 
Ethan A Merritt