c - Is it necessary to pass the file pointer to main? -

i quite new c programming , have make program asks user enter file name open , open file , print values sorted.

will need pass file pointer main, or can open file in 1 function , can work file throughout other functions?

int getfile () {     char file_name[100];      file* fp;                int rc;                   printf("enter file name: ");     rc = scanf("%s", file_name);     if (rc != 1)         printf ("error");      fp = fopen(file_name, "r");      return 0;  }     

do have pass file pointer here main?

just pass file name argument main function, maybe want. might use int main(int argc, char* argv[]), example:

int main(int argc, char* argv[]) {     file*  fp;     if (argc == 1)         printf("usage : a.out filename\n");     else     {         if (fp = fopen(*++argv, "r") != null)         {             /*your code here*/         }     }     return 0; }