Multiple structs and outputting them

The code is essentially complete but I am having difficulty outputting the numerical inputs. The areas that are causing the program to fail have been commented out.

Code:

  #include <stdio.h>
  #include <string.h>

  typedef struct
       { char make[15];
         char model[15];
         int odom;
       }auto_t;

  typedef struct
       { char manmonth[10];
         int manday;
         int manyear;
         char purmonth[10];
         int purday;
         int puryear;
       }date_t;

  typedef struct
       { int tankcap;
         double tankcur;
       }tank_t;


  void scan_auto (auto_t *a_car);
  void scan_dates (date_t *a_date);
  void scan_tank (tank_t *a_tank);
  void print_auto (auto_t a_car);
  void print_dates (date_t a_date);
  void print_tank (tank_t a_tank);
 

 int main(void)
  {
   auto_t this_car;
   scan_auto(&this_car);
   date_t this_date;
   scan_dates(&this_date);
/* tank_t this_tank;
   scan_tank(&this_tank);*/
   print_auto(this_car);
   print_dates(this_date);
/* print_tank(this_tank);*/
   return 0;
  }

  void scan_auto(auto_t *a_car)
  {printf("Enter make of automobile: ");
   gets((*a_car).make);
   printf("Enter model of automobile: ");
   gets((*a_car).model);
/* printf("Enter mileage of automobile: ");
   gets((*a_car).odom);*/
   return;
  }
  void scan_dates(date_t *a_date)
  {printf("Enter the month of manufacturing: ");
   gets((*a_date).manmonth);
/* printf("Enter the day of manufacturing: ");
   gets((*a_date).manday);
   printf("Enter the year of manufacturing: ");
   gets((*a_date).manyear);*/
   printf("Enter the month of purchase: ");
   gets((*a_date).purmonth);
/* printf("Enter the day of purchase: ");
   gets((*a_date).purday);
   printf("Enter the year of purchase: ");
   gets((*a_date).puryear);*/
   return;
  }
  void print_auto(auto_t a_car)
  {printf("Entering this automobile\n");
   printf("Make is %s\n", a_car.make);
   printf("Model is %s\n", a_car.model);
/* printf("Mileage is %s\n", a_car.odom);*/
   return;
  }

  void print_dates(date_t a_date)
  {printf("Manufactured in %s\n", a_date.manmonth);
/* printf("on the %sth day of", a_date.manday);
   printf("%s", a_date.manyear);*/
   printf("Purchased in %s\n", a_date.purmonth);
/* printf("on the %sth day of", a_date.purday);
   printf("%s", a_date.puryear);*/
   return;
  }

/*void scan_tank(tank_t *a_tank)
  {printf("Enter the tank capacity: ");
   gets((*a_tank).tankcap);
   printf("Enter current fuel level in gallons: ");
   gets((*a_tank).tankcur);
   return;
  }

  void print_tank(tank_t a_tank)
  {printf("Tank capacity: %s gallons\n", a_tank.tankcap);
   printf("Current tank level: %s gallons\n", a_tank.tankcur);
   return;
  }*/

I imagine it's something simple such as scanning the data in as the wrong datatype but I couldn't figure it out.

1. Never ever use gets, use fgets instead, read the FAQ
2. You cannot use fgets (or gets) on anything but strings. A sensible way to read ints would be fgets into a buffer, followed by sscanf, or strtol to convert to an int. Read the FAQ.

References:
gets sucks FAQ
validate input FAQ

well, how do u scan a number from the user

Code:

 printf("Enter mileage of automobile: ");
   gets((*a_car).odom); // scanf("%d",&(*a_car).odom);

you have made the same mistake again in the other three function. to read integer u dont need to use gets fucntion unless the u need to read a string from the user. gets fucntion is only to be used if u are reading string from the users. to be honest gets fucntion shouldn't be used!! why ?? read the FAQ u gets a very good reason of why gets fucntion should be used. instead u can use fgets which is meant to read a string from a specified input stream here is am sample code of how to use fgets

Code:

char str[10];

fgets(str,sizeof(str),stdin);   //note: u are specifing the imput stream as stdin standard input thats the keyboard

make sure u read the FAQ and make changes in your code so that u dont read integer using get fucntion use scanf instead

ssharish2005

Yes, that's more or less your problem. gets() takes a pointer to a char... ie, a string. However, I recommend not using gets(), since it doesn't check for buffer overruns. (Where you type "foo", someone will type, "foofoofoofoo...") There's probably a few FAQ articles on this.

Also:

Code:

(*a_tank).tankcur

is equivalent to:

Code:

a_tank->tankcur

Where the latter is much neater. Look up the -> operator.

As for reading numbers, you'll need to convert the input from a string. You can use scanf() or a variant thereof, or do it yourself, perhaps using strtod (for doubles) and strtol.

ssharish2005,

Code:

scanf("%d",&(*a_car).odom);

That won't cope well at all if something other than an integer is entered. See the FAQ I posted above for better solutions.

Originally Posted by cwr

ssharish2005,

Code:

scanf("%d",&(*a_car).odom);

That won't cope well at all if something other than an integer is entered. See the FAQ I posted above for better solutions.

hope this workd fine for that

Code:

 scanf("%d",&a_car->odom);

thax for pointing me out CWR

ssharish2005

Code:

scanf("%d",&a_car->odom);

That won't cope well, either. It's the same thing. See the FAQ!

so is that should be like this

Code:

fgets(a_cars->odom,10,stdin);

provided odom is declared a char * in the structure

ssharish2005