Передать путь в качестве параметра командной строки - C (СИ)

int main(int argc, char* argv[])
{
    char main[1000], second[1000] = "", file_name[100];
    int choose, i=1, cor=1, b, a=0, c=0,par;
    FILE* file;
    choose = 0;
    *file_name = argv[1];
    if (file_name != NULL)
    {
        *file_name = argv[1];
        file = fopen( file_name, "r" );
        if (file != NULL) 
           {
           fgets (main, 300 , file);
           fclose( file );
                   if (strlen(main) < 1) 
                    printf("Hello\n");
                   else
                    {
                    perform (i, cor, b, a, main, second);
                    file = fopen( file_name, "w" );
                    printf ("second : %s\n", main);
                    printf ("second : %s\n", second); 
                    fputs(second, file);
                    }
           }
           else
               printf ("Incorrect input\n");
           }