To facilitate the job of the users and developers, all the programs in Gnuastro share some basic command-line options for the options that are common to many of the programs. The full list is classified as Input/Output options, Processing options, and Operating mode options. In some programs, some of the options are irrelevant, but still recognized (you will not get an unrecognized option error, but the value is not used). Unless otherwise mentioned, these options are identical between all programs.
GNU Astronomy Utilities 0.20 manual, April 2023.