Compilare: user.cpp: In function ‘void read(int&)’: user.cpp:26:32: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while (!(buff[counter] >= '0' && buff[counter] <= '9' || buff[counter] == '-')) ^ user.cpp:28:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, BUFLEN, stdin), counter = 0; ^ user.cpp:33:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, BUFLEN, stdin), counter = 0; ^