Usage: gdaltindex [--help] [--help-general]
                  [-f <format>] [-tileindex <field_name>] [-write_absolute_path]
                  [-skip_different_projection] [-t_srs <target_srs>]
                  [-src_srs_name field_name] [-src_srs_format {AUTO|WKT|EPSG|PROJ}]
                  [-lyr_name <name>] <index_file> <gdal_file> [<gdal_file>]...

e.g.
  % gdaltindex doq_index.shp doq/*.tif

NOTES:
  o The index will be created if it doesn't already exist.
  o The default tile index field is 'location'.
  o Raster filenames will be put in the file exactly as they are specified
    on the commandline unless the option -write_absolute_path is used.
  o If -skip_different_projection is specified, only files with same projection ref
    as files already inserted in the tileindex will be inserted (unless t_srs is specified).
  o If -t_srs is specified, geometries of input files will be transformed to the desired
    target coordinate reference system.
    Note that using this option generates files that are NOT compatible with MapServer < 6.4.
  o Simple rectangular polygons are generated in the same coordinate reference system
    as the rasters, or in target reference system if the -t_srs option is used.