Compilare: user.c: In function ‘main’: user.c:9:31: warning: unused variable ‘last’ [-Wunused-variable] int index, size, previous, last, number, line_length; ^ user.c:9:21: warning: unused variable ‘previous’ [-Wunused-variable] int index, size, previous, last, number, line_length; ^ user.c:24:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(input, "%d\n", &size); ^ user.c:27:10: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result [-Wunused-result] fgets(line, sizeof(line), input); ^