cpp.md

1.Link error of "ld: library not found for -lSystem" on MacOS.

export LIBRARY_PATH="$LIBRARY_PATH:/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib"

see: https://stackoverflow.com/questions/56156520/gfortran-error-ld-library-not-found-for-lsystem-when-trying-to-compile