interface_build {
    {r.fill.dir} 0
    {Creates a depressionless elevation map and flow direction map.}
    {entry input {Input elevation map:} 0 raster}
    {entry elevation {Output depressionless elevation map:} 0 raster}
    {entry direction {Output flow direction map:} 0 raster}
    {checkbox type {Create GRASS format flow direction map} "" grass}
    {checkbox type {Create AGNPS format flow direction map} "" agnps}
    {checkbox type {Create ANSWERS format flow direction map} "" answers}
    {checkbox -f {Fill only single grid cell sinks and exit.} "" -f}
}