/usr/share/gmt/custom/invtriangle.def is in gmt-common 5.3.1+dfsg-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 | # $Id: invtriangle.def 12822 2014-01-31 23:39:56Z remko $
#
# Definition file for inverted triangle symbol. Use in psxy
# as -Skinvtriangle/size. Unlike -Si, this allows for
# using patterns as fill
#
-0.433012701892 0.25 M
0.433012701892 0.25 D
0 -0.5 D
|