/*-------------------------------------------------------------------
  xsubstr(x,startcol,length,padchar)
   returns string from within x starting at startcol for length characters
   padded with padchar if returned length does not match length
   If startcol = 0 then 1 is used
   If length = 0 then from startcol to end of string
   If padchar = "" then padchar becomes " "
   Mark McDonald 2008
  -------------------------------------------------------------------*/
char *xsubstr(char *x, int xsp, int xn, char*xpad){
  char *xret = "";
  char *xpadchars ="";
  int xlen;
  xlen = strlen(x);
  if(xsp > xlen){return(xret);}
  if(xsp == 0){xsp = 1;}
  if(xpad == ""){strcpy(xpad," ");}            /*Set Default if Needed*/
  if(xn > 0){
    xpadchars = strgenstr(xpad, xn);
    strcat(x,xpadchars);
  }//endif
  if(xn == 0){
   xn = xlen - xsp + 1;
  }//endif
  xret = strgetsubstr(x,xsp,xn);
return(xret);
}//xsubstr