OK, so here is the deal.

In my language I have some commands, say

XYZ 3 5
GGB 8 9
HDH 8783 33

And in my Lex file

XYZ { return XYZ; }
GGB { return GGB; }
HDH { return HDH; }
[0-9]+ { yylval.ival = atoi(yytext); return NUMBER; }
\n  { return EOL; }

In my yacc file

start : commands
    ;

commands : command
         | command EOL commands
    ;

    command : xyz
            | ggb
            | hdh
    ;

    xyz : XYZ NUMBER NUMBER { /* Do something with the numbers */ }
       ;

    etc. etc. etc. etc.

My question is, how can I get the entire text

XYZ 3 5
GGB 8 9
HDH 8783 33

Into commands while still returning the NUMBERs?

Also when my Lex returns a STRING [0-9a-zA-Z]+, and I want to do verification on it's length, should I do it like

rule: STRING STRING { if (strlen($1) < 5 ) /* Do some shit else error */ }

or actually have a token in my Lex that returns different tokens depending on length?