#include <stdio.h>;
#include <stdlib.h>;

char *floatToString(double fZ,const int slen,const int alen);

main(int argc,char *argv[])
{
      fprintf(stdout,"[%s]\n",floatToString(atof(argv[1]), atoi(argv[2]), atoi(argv[3])));

      return;
}

char *floatToString(double fZ,const int slen,const int alen)
{
      char tmpstr[256];

      memset(tmpstr,'\0',256);
      sprintf(tmpstr,"%*.*lf",slen,alen,fZ); //-- 這里控制精度
      return(tmpstr);
}