$ gcc -c chklc.c
$ gcc -c crypt3.c
$ gcc -c chklc_fips.c
$ gcc -o chklc_fips chklc_fips.o chklc.o crypt3.o

$ export FREESURFER_HOME=<parent path to ./bin>
$ export FS_LICENSE=<abs path to license file>

./chklc_fips
Trying license file <your entry>
email <your entry>
magic <your entry>
key  <your entry>
key2 <your entry>
gkey  <your entry>
4 line license file
crypt_gkey <your entry>
chklc() done
