gcc

  c-preprocessor (GNU cpp) environment-variable: $CPATH #cpp -v /usr/include   compiler (GNU cc) environment-variable: $CPATH #gcc -E -Wp,-v – /usr/include   linker (GNU ld) environment-variable: $LIBRARY_PATH #ld –verbose | grep -i ‘search_dir’ SEARCH_DIR(“/lib”); SEARCH_DIR(“/usr/lib”); SEARCH_DIR(“/usr/local/lib”)