Here is the message displayed:
Setting up environment for FreeSurfer/FS-FAST (and FSL)
FREESURFER_HOME /Applications/freesurfer
FSFAST_HOME /Applications/freesurfer/fsfast
FSF_OUTPUT_FORMAT nii.gz
SUBJECTS_DIR /Applications/freesurfer/subjects
MNI_DIR /Applications/freesurfer/mni
Jordans-MacBook-Air-2:~ jordanfowler$ > cp $FREESURFER_HOME/subjects/sample-001.mgz .
-bash: /Applications/freesurfer/subjects/sample-001.mgz: Permission denied