How does linuxbrew looks for gcc

For example, when looking for gcc-4.4, use --cc=gcc-4.4 or set HOMEBREW_GCC=gcc-4.4 and gcc-4.4 must be in environmental variable PATH, and its name CANNOT be gcc44 or anything else. You could do something like this

ln -s /usr/bin/gcc44 $prefix/bin/gcc-4.4
ln -s /usr/bin/g++44 $prefix/bin/g++-4.4
ln -s /usr/bin/gfortran44 $prefix/bin/gfortran-4.4