#include <stdlib.h>
#include <grass/gis.h>

int 
do_histogram (char *name, char *mapset)
{
    CELL *cell;
    struct Cell_head cellhd;
    struct Cell_stats statf;
    int nrows, ncols, row;
    int fd;

    if (G_get_cellhd (name, mapset, &cellhd) < 0)
        return 0;
    G_set_window (&cellhd);
    fd = G_open_cell_old (name, mapset);
    if (fd < 0)
        return 0;
    nrows = G_window_rows();
    ncols = G_window_cols();
    cell = G_allocate_cell_buf();

    G_init_cell_stats (&statf);
    for (row = 0; row < nrows; row++)
    {
        if (G_get_map_row_nomask (fd, cell, row) < 0)
            break;
        G_update_cell_stats (cell, ncols, &statf);
    }
    G_close_cell (fd);
    G_free (cell);
    if (row == nrows)
        G_write_histogram_cs (name, &statf);
    G_free_cell_stats (&statf);
    return row == nrows;
}