Compilare: user.c: In function ‘main’: user.c:161:5: 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:118:13: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread (buff, 1, MASK, fin); ^~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:128:13: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread (buff, 1, MASK, fin); ^~~~~~~~~~~~~~~~~~~~~~~~~~