/in/ex4.c: In function 'main':
/in/ex4.c:7:13: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'long int *' [-Wformat=]
     scanf("%d",&a);
             ^
/in/ex4.c:8:42: warning: passing argument 4 of 'strftime' makes pointer from integer without a cast [-Wint-conversion]
     strftime(buff,26,"%Y-%m-%d %H:%M:%S",a);
                                          ^
In file included from /in/ex4.c:2:0:
/usr/include/time.h:205:15: note: expected 'const struct tm * restrict' but argument is of type 'long int'
 extern size_t strftime (char *__restrict __s, size_t __maxsize,
               ^~~~~~~~