Finds the Freesurfer from system environment or getOption("freesurfer.path")
for location of Freesurfer functions
Usage
get_fs(bin_app = c("bin", "mni/bin", ""))
Value
NULL if Freesurfer in path, or bash code for setting up Freesurfer DIR
Arguments
bin_app
Should bin be added to the freesurfer path?
All executables are assumed to be in FREESURFER_HOME/bin/. If not, and
bin_app = "", they will be assumed to be in FREESURFER_HOME/.