[GRASS-dev] Re: [GRASS-SVN] r46717 - grass/branches/releasebranch_6_4/scripts/v.build.all

[Glynn Clements]

Hamish wrote:

> > >     CMD="v.build map=${VECT}@${MAPSET}"
> > > -    g.message "$CMD"
> > > +    g.message message="$CMD"
> > >     $CMD
> > >  done
> MNeteler:
> > ... is this a needed change?
> ...
> > Most are without this parameter...
> 
> Needed in this case because the string contains a '=', which
> confuses the parser.

That should really be fixed in the parser. Even in 6.x, an option name
cannot contain a space.

In 6.x, the test for whether an argument is an option finds the first
'=' in the string and checks that the immediately preceding character
is alphanumeric.

	static int is_option(const char *string)
	{
	    const char *p = strchr(string, '=');
	
	    if (!p)
		return 0;
	    if (p == string)
		return 0;
	    p--;
	    if (!strchr("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789", *p))
		return 0;
	
	    return 1;
	}

In 7.0, the test uses strspn() to find the length of the prefix
consisting entirely of (lower-case) alphanumeric characters and
underscores, then checks that the following character is an '=' and
that the prefix doesn't begin or end with an underscore:

	static int is_option(const char *string)
	{
	    int n = strspn(string, "abcdefghijklmnopqrstuvwxyz0123456789_");
	
	    return n > 0 && string[n] == '=' && string[0] != '_' && string[n-1] != '_';
	}

It would be simple to back-port the 7.0 version to 6.x. Compatibility
requires adding the upper-case characters, which are allowed in option
names in 6.x (e.g. r.terraflow's STREAM_DIR= option). Technically, the
check for a leading underscore should be removed, but I'm not sure
that actually matters.

-- 
Glynn Clements <glynn at gclements.plus.com>