/opt/IBM/openxlC/17.1.1/bin/ibm-clang -pthread  -Wall -Wextra -Werror=implicit-function-declaration termios/tcgetwinsize.c -o termios/tcgetwinsize -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -latomic
termios/tcgetwinsize.c:52:8: error: call to undeclared function 'tcsetwinsize'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
                if ( tcsetwinsize(pty, &ws) < 0 )
                     ^
termios/tcgetwinsize.c:57:8: error: call to undeclared function 'tcgetwinsize'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
                if ( tcgetwinsize(pty, &new_ws) < 0 )
                     ^
2 errors generated.