text: /*
   * The authors of this software are Rob Pike and Ken Thompson.
   *              Copyright (c) 2002 by Lucent Technologies.
   * Permission to use, copy, modify, and distribute this software for any
   * purpose without fee is hereby granted, provided that this entire notice
   * is included in all copies of any software which is or includes a copy
   * or modification of this software and in all copies of the supporting
   * documentation for such software.
   * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
   * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
   * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
   * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
   */
  #include <stdarg.h>
  #include <string.h>
  #include "utf.h"
  #include "fmt.h"
  #include "fmtdef.h"
  
  /* format the output into f->to and return the number of characters fmted  */
  
  int
  dorfmt(Fmt *f, const Rune *fmt)
  {
  	Rune *rt, *rs;
  	int r;
  	char *t, *s;
  	int nfmt;
  
  	nfmt = f->nfmt;
  	for(;;){
  		if(f->runes){
  			rt = f->to;
  			rs = f->stop;
  			while((r = *fmt++) && r != '%'){
  				FMTRCHAR(f, rt, rs, r);
  			}
  			f->nfmt += rt - (Rune *)f->to;
  			f->to = rt;
  			if(!r)
  				return f->nfmt - nfmt;
  			f->stop = rs;
  		}else{
  			t = f->to;
  			s = f->stop;
  			while((r = *fmt++) && r != '%'){
  				FMTRUNE(f, t, f->stop, r);
  			}
  			f->nfmt += t - (char *)f->to;
  			f->to = t;
  			if(!r)
  				return f->nfmt - nfmt;
  			f->stop = s;
  		}
  
  		fmt = __fmtdispatch(f, fmt, 1);
  		if(fmt == nil)
  			return -1;
  	}
  	return 0;		/* not reached */
  }
  