cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wchar/putwc.c -o wchar/putwc -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
wchar/putwc.c: In function ‘main’:
wchar/putwc.c:13:14: error: implicit declaration of function ‘putwc’; did you mean ‘putc’? [-Wimplicit-function-declaration]
   13 |         if ( putwc(c, fp) == WEOF )
      |              ^~~~~
      |              putc
wchar/putwc.c:13:27: warning: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Wsign-compare]
   13 |         if ( putwc(c, fp) == WEOF )
      |                           ^~