gmtdefaults - To list current GMT defaults gmtdefaults -D | L gmtdefaults lists the GMT parameter defaults if the option -D is used. To change some of the settings, use any texteditor to edit the file .gmtdefaults in your home or current directory. ... D Print the system GMT defaults to standard output. ... If you have typographical errors in your .gmtdefaults file(s), a warning message will be issued, and the GMT defaults for the affected parameters will be used. gmt , gmtset . ...