function::set_user_long - Linux


function::set_user_long is a powerful command used to set the user data associated with a GDAL raster band. This allows developers to store custom information or metadata in a structured and accessible manner.


gdal_err set_user_long(Band nBand, int name, long nValue)


  • nBand: The band index for which the user data will be set.
  • name: The name of the user data item.
  • nValue: The new value to be stored.


// Set user data named "elevation" with a value of 1000
gdal_err err = set_user_long(band, "elevation", 1000);

// Check if user data named "description" exists
if (band->GetUserLong("description", nullptr) != nullptr) {
    // Do something

Common Issues

  • Name collisions: User data names should be unique within a band to avoid overwriting or ambiguity.
  • Type safety: Verify that the value being stored is of type long.


function::set_user_long can be used in conjunction with other GDAL functions to create complex geospatial applications. For example, it can be combined with function::GetRasterBand() to access raster bands, and with function::GetRasterCount() to iterate through all bands in a dataset.

Related Commands