Compilare: user.c: In function ‘main’: user.c:45:9: warning: passing argument 1 of ‘scanf’ from incompatible pointer type [-Wincompatible-pointer-types] scanf(input, "%i", &a); ^ In file included from /usr/include/features.h:367:0, from /usr/include/stdio.h:27, from user.c:1: /usr/include/stdio.h:446:12: note: expected ‘const char * restrict’ but argument is of type ‘FILE * {aka struct _IO_FILE *}’ extern int __REDIRECT (scanf, (const char *__restrict __format, ...), ^ user.c:46:9: warning: passing argument 1 of ‘scanf’ from incompatible pointer type [-Wincompatible-pointer-types] scanf(input, "%i", &b); ^ In file included from /usr/include/features.h:367:0, from /usr/include/stdio.h:27, from user.c:1: /usr/include/stdio.h:446:12: note: expected ‘const char * restrict’ but argument is of type ‘FILE * {aka struct _IO_FILE *}’ extern int __REDIRECT (scanf, (const char *__restrict __format, ...), ^ user.c:41:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(input, "%i", &T); ^ user.c:45:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf(input, "%i", &a); ^ user.c:46:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf(input, "%i", &b); ^