You installed GMT-5.4.5 and the text editing software (Mi), created a working folder (GMT_exe), and saved the topographic map data (etopo1) in GMT_exe, right?
* ETOPO1_Bed_g_gmt4.grd (933.5 MB): Please check the file name, file size, and save location.
Start Mi, create a new file, and save it with a different name (test.sh). Please also type in the extension “.sh” to indicate that it is a shell script file. Let's save it to /Users/user/GMT_exe/GMT_shell/.

Select "LF (Mac/UNIX)" from the tab at the top of the Mi screen.
(Mac/UNIX should be selected in Mi's initial settings)
Type the following in the first line of the test.sh file opened on Mi and save it.
(Just copy and paste the text)
gmt pscoast -R120/150/20/50 -JM12 -Bxa10f1g5 -Bya5f1g5 -Di -W1 -G150 -V > ./GMT_exe/test.eps
