well, its been a while since I've done this programming business, so bear with me

back in college i took a C/unix course, and retained my old book. Recently I've gotten tired of having to calculate out my weight & balance every time i go flying...its a general pain (not really, but still ). So not having anything to do one day, i decided to dust that old thing off and see what i remembered!

well...i was a bit but i got there

here's a script file of my program that I've got so far, the problem is, after making my "choice" from the menu, it (as you can see) just sits and does nothing. Now if i 'comment' out the "ac" funciton, and manually define all of my data in the main body, the whole thing works, quite beautifully actually!! but still, for some reason, its liking to not get past the "ac" function. I can't see anything, but again, its been a while, let me know what you com up with!

thanks

-flyboy.

#include<stdio.h>


void menu (int* choice);
void ac (int choice, FILE* plane,int input[], int* MAX_WEIGHT, int* MAX_CG, int arm[]);
void getdata (FILE* plane, int input []);
int calc (int MAX_WEIGHT, int MAX_CG,int input[], int arm[], int* weight, int* balance);
void print( int weight, int balance, int oepration);

int main (void)
{

 
  int choice;
  FILE* plane;
  int input [15] = {0};
  int arm [6] = {0};
  int weight, balance = 0;

  int MAX_WEIGHT, MAX_CG;//upper limits of the weight and CG per plane
  int operation;

  menu(&choice);
  
  ac(choice, plane, input, &MAX_WEIGHT, &MAX_CG, arm);  // ac or a/c is short for Aircraft. Easier separation between function and file called plane
/*  plane = fopen("C172.DAT", "r");
  input[0] = 1491;
  MAX_WEIGHT = 2550;
  MAX_CG = 47;
*/

  getdata(plane, input);
  operation = calc (MAX_WEIGHT, MAX_CG,input, arm, &weight, &balance); // return value of '1' will be inside limits, '0' will be outside limits
  print(weight, balance, operation);

  return 0;

}


//=================================menu function================================


void menu (int* choice)
{
  printf("****************WELCOME!****************");
  printf("\n");
  printf("This program enabels you to calculate\n");
  printf("your weight and balance. Please enter\n");
  printf("a number and key <retrun> to make your\n");
  printf("selection from the menu below:\n");
  printf("\n");
  printf("1| Cessna 172\n");
  printf("2| Cherokee 6\n");
  printf("3| Piper Cub\n\n\n");
  printf("Enter your choice:");
  scanf("%d", choice);

 

 return;
}


//=====================================select data=========================

void ac (int choice, FILE* plane, int input[], int* MAX_WEIGHT, int* MAX_CG, int arm[])
{
  
 switch (choice)
     {
    case 1: plane =  fopen("C172.DAT", "r");
        input[0] = 1491;
        *MAX_WEIGHT = 2550;
        *MAX_CG = 47;
          arm[0] = 39;
          arm[1] = 35;
          arm[2] = 35;
          arm[3] = 74;
          arm[4] = 97;
          arm[5] = 116;
        break;
    case 2: plane =  fopen("Piper6.DAT", "r");
        input[0] = 1980 ;
            *MAX_WEIGHT = 3674 ;
        *MAX_CG = 96;
        arm[0] = 85;
        arm[1] = 85;
        arm[2] = 95;
        arm[3] = 118;
        arm[4] = 156;
        arm[5] = 179;

         
        break;
    case 3: plane =  fopen("Cub.DAT", "r");
        input[0] = 765.7;
        *MAX_WEIGHT = 1200;
        *MAX_CG = 23.7;
         arm[0] = 17;
         arm[1] = 9;
         arm[2] = 36;
         arm[3] = -18;
         arm[4] =  49;
        break;
      }
  
return;

}
//============================================getting data===============


void getdata (FILE* plane, int input[])
{
  char charin;
  int i = 1;

  while( (charin = fgetc(plane)) != EOF)
  {
   printf("%c", charin);
   while( (charin = fgetc(plane)) != '\n'  )
   {
     printf("%c", charin);
   }
    scanf("%d", &input[i]);
    i++;
  }
 

  return;
}



//===================calc data=========================


int calc (int MAX_WEIGHT, int MAX_CG, int input[], int arm[],  int* weight, int* balance)
{
  int moment;
  *weight = 0;

  for(int i = 0; i <=5; i++)
  {
    *weight += input[i] ;
    *balance += (input[i] * arm [i]); // one easy way to calculate the moment of inertia is to multiply the wieght by the arm and add it all up
  
  }//for

  printf("%d, %d", *weight , * balance);

  if ( (*weight > MAX_WEIGHT) || ((*balance / *weight) > MAX_CG) )
   return 0;
  else
    return 1;

}
//=========================print data======================


void print( int weight, int balance, int operation)
{

  if (operation == 0)
  {printf("\nI'm sorry, but your plane is not withing the flight envelope.");
   printf("\nPlease make adjustments so it is within proper weight and balance.\n");
  }
   else
   {
     printf("\n\nYour total weight is: %d\n", weight);
     printf("Your CG is: %d\n", (balance / weight ) );
   }

   return;
}//print results
]0;flyboy@csc-linux1:~[flyboy@csc-linux1 ~]$ gcc std-std=c99 term.c
]0;flyboy@csc-linux1:~[flyboy@csc-linux1 ~]$ a.out
****************WELCOME!****************
This program enabels you to calculate
your weight and balance. Please enter
a number and key <retrun> to make your
selection from the menu below:

1| Cessna 172
2| Cherokee 6
3| Piper Cub


Enter your choice:1
1
1
1
1
^C
]0;flyboy@csc-linux1:~[flyboy@csc-linux1 ~]$ exit
exit

Script done on Thu 30 Apr 2009 11:08:53 PM CDT

You need to pass a pointer to plane instead of itself i.e.

void ac (int choice, FILE** plane,int input[], int* MAX_WEIGHT, int* MAX_CG, int arm[]);

I LOVE YOU!!!!!!!


hahaha, thanks alot, I knew it had to be something simple. I was trying to remember if the file declarations were like array's in that you don't have to do that, but after you said that i did some digging (just for giggles) and i did find that the book mentioned that.

program works like butta now, I'll post a script tomorow!