/in/ex1.c: In function 'main':
/in/ex1.c:14:9: error: implicit declaration of function 'strlwr'; did you mean 'strlen'? [-Werror=implicit-function-declaration]
         strlwr(argv[n]);
         ^~~~~~
         strlen
/in/ex1.c:12:9: error: unused variable 'count' [-Werror=unused-variable]
     int count[20]={0};
         ^~~~~
cc1: all warnings being treated as errors