Re: Local Versus Global Command Options

On 2025-02-14, Arne Vajhøj <arne@vajhoej.dk> wrote:

>
You can define a bit in CLD. Including specifying that
something is a number and something else is from an
enumeration list.
>
$ type fun3.cld
define verb fun3
     image "sys$disk:[]fun3"
     parameter p1, value(type=$file, list, required)
qualifier q, value(type=threeitems, list, required), placement=local
define type threeitems
     keyword a, value(type=$number, required)
     keyword b, value(type=$quoted_string, required)
     keyword c, value(type=myenum, required)
define type myenum
     keyword x
     keyword y
     keyword z
$ type fun3.pas
[inherit('sys$library:pascal$cli_routines')]
program fun3(input,output);
>
type
    pstr = varying [255] of char;
>
var
    fnm, a, b, c : pstr;
>
begin
    while odd(cli$get_value('P1', fnm.body, fnm.length)) do begin
       write(fnm);
       if odd(cli$present('Q')) then begin
          cli$get_value('Q.A', a.body, a.length);
          write(' A=', a);
          cli$get_value('Q.B', b.body, b.length);
          write(' B=', b);
          cli$get_value('Q.C', c.body, c.length);
          write(' C=', c);
       end;
       writeln;
    end;
end.
$ pas fun3
$ lin fun3
$ set comm fun3
$ fun3 x.dat/q=(a:1,b:"This is x",c:x), y.dat/q=(a:2,b:"This is y",c:y),
z.dat/q=(a:3,b:"This is z",c:z)
x.dat A=1 B="This is x" C=X
y.dat A=2 B="This is y" C=Y
z.dat A=3 B="This is z" C=Z
$ on error then continue
$ fun3 x.dat/q=(a:x,b:"This is x",c:x), y.dat/q=(a:2,b:"This is y",c:y),
z.dat/q=(a:3,b:"This is z",c:z)
%DCL-W-NUMBER, invalid numeric value - supply an integer
  \X\
$ fun3 x.dat/q=(a:1,b:"This is x",c:xdat), y.dat/q=(a:2,b:"This is
y",c:y), z.dat/q=(a:3,b:"This is z",c:z)
%DCL-W-IVKEYW, unrecognized keyword - check validity and spelling
  \XDAT\
>

But it is no longer ffmpeg syntax, but convoluted DCL syntax. It also
doesn't help you with the main problem I mentioned, which is parsing
and validating the filter syntax. To give you an idea of the scale of
the problem, here is the mplayer man page (which I know a lot better
than the ffmpeg filters):

https://linux.die.net/man/1/mplayer

That is a _very_ long man page, so search for "-vf-add" and you should
be in a section marked "Video Filters". In that section are the list of
available filters, starting with the crop one I mentioned earlier.

How would you turn the list of filters, each with their own syntax, into
something that can be validated by DCL ? As a reminder, it is critical
that the filters are available to the program in the order they were
specified on the command line.

Simon.

--
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.