Compilare: main.c: In function 'main': main.c:20:8: warning: pointer targets in passing argument 1 of 'fgets' differ in signedness [-Wpointer-sign] fgets(text, 1000000, f); ^~~~ In file included from /usr/include/stdio.h:936:0, from main.c:2: /usr/include/x86_64-linux-gnu/bits/stdio2.h:253:1: note: expected 'char * restrict' but argument is of type 'unsigned char *' fgets (char *__restrict __s, int __n, FILE *__restrict __stream) ^~~~~ main.c:31:7: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if (len != 0) ^ main.c:20:2: warning: ignoring return value of 'fgets', declared with attribute warn_unused_result [-Wunused-result] fgets(text, 1000000, f); ^~~~~~~~~~~~~~~~~~~~~~~