cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wchar/fwscanf.c -o wchar/fwscanf -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
wchar/fwscanf.c: In function ‘main’:
wchar/fwscanf.c:12:14: error: implicit declaration of function ‘fputws’; did you mean ‘fputs’? [-Wimplicit-function-declaration]
   12 |         if ( fputws(L"hello world 42", fp) == -1 )
      |              ^~~~~~
      |              fputs
wchar/fwscanf.c:20:19: error: implicit declaration of function ‘fwscanf’; did you mean ‘fscanf’? [-Wimplicit-function-declaration]
   20 |         int ret = fwscanf(fp, L"hello %5ls %d", world, &value);
      |                   ^~~~~~~
      |                   fscanf