Compilare: user.c: In function ‘main’: user.c:20:5: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if((*(s+i)<'a' || *(s+i)>'z') && (*(s+i)<'A' || *(s+i)>'Z')) ^ user.c:18:7: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread(s,sizeof(char),l,f); ^