Compilare: user.cpp: In function ‘int main()’: user.cpp:73:9: warning: unused variable ‘x1’ [-Wunused-variable] int x1, x2, x3, x4, x5; ^ user.cpp:73:13: warning: unused variable ‘x2’ [-Wunused-variable] int x1, x2, x3, x4, x5; ^ user.cpp:73:17: warning: unused variable ‘x3’ [-Wunused-variable] int x1, x2, x3, x4, x5; ^ user.cpp:73:21: warning: unused variable ‘x4’ [-Wunused-variable] int x1, x2, x3, x4, x5; ^ user.cpp:73:25: warning: unused variable ‘x5’ [-Wunused-variable] int x1, x2, x3, x4, x5; ^ user.cpp: In function ‘char nextch()’: user.cpp:12:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fi); ^