cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration ftw/nftw.c -o ftw/nftw -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
ftw/nftw.c:6:10: fatal error: ftw.h: No such file or directory
    6 | #include <ftw.h>
      |          ^~~~~~~
compilation terminated.