This is an inefficient format, so be warned: you are going to get a datafile.
The NOAA NCEP-DOE Reanalysis-2 Daily gaussian_grid surface Daily Mean of Downward Longwave Radiation Flux at Surface data are available as a columnar table, i.e. as multiple columns of data, intended primarily to be read. However, if you have other intentions for this table, or simply do not like the default choices, you may want to choose from the columnar tables with options.