Compilare: user.c: In function ‘main’: user.c:189:5: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread (buff, 1, MASK, fin); ^~~~~~~~~~~~~~~~~~~~~~~~~~ user.c: In function ‘reader’: user.c:117:13: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread (buff, 1, MASK, fin); ^~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:127:13: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread (buff, 1, MASK, fin); ^~~~~~~~~~~~~~~~~~~~~~~~~~