Thread: Seg fault

Code:

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

#define TWOI 2
#define CLASS_SIZE 20
#define NAME_SIZE 20
#define ONEI 1
#define SALARY_SIZE 2
#define TEXT_BUFFER 81
#define ZEROI 0

struct employee
{
  char *firstName;
  char *lastName;
  int id;
  char *class;
  double salary[SALARY_SIZE];
  struct employee *nextEmployee;
};

void hire(FILE **, char [], struct employee **);
void printList(struct employee *);

Thats my constants file

Code:

#include "hw3AndyFoxConstants.c"

int main()
{
 printf("hello");
 struct employee *firstEmployee = NULL;
 FILE *infile;
 char lineOfText[NAME_SIZE] = {""};
 
 infile  = fopen("hw3AndyFoxInput.dat", "r");
 fgets(lineOfText, NAME_SIZE, infile);
 while(!feof(infile))
 {
   if(lineOfText[ZEROI] == '*')
   {
     switch(lineOfText[TWOI])
     {
      case 'H':
	    hire(&infile, lineOfText, &firstEmployee);
	    printList(firstEmployee);
        break;
      case 'I':
       // initial();
        break;
      case 'P':
        //promote();
	    break;
	  case 'T':
        //transfer();
        break;
	  case 'E':
	    //endOfData();
        break;
      default:
        printf("Invalid input\n");
 	    break;
      }
    }
  }
return(ZEROI);
}

This is part of my main program.
I keep getting a seg fault over and over, the program wont even print the "hello" statement I put at the top of the main function. I have figured that if i comment out all the commands having to do with the input file it will print the hello. The program is working with a singularly linked list.

I've been trying many things for the past day, and from what I can tell is that it is not even reaching the main function. The printf("hello"); is not printing, which is the first thing in the main function. In XCODE on my mac, I get a "exited due to signal 10 (SIGBUS). On my schools linux server, I can compile the program with gcc but when I type a.out to run it nothing happens I just get a blank line and no command prompt and it stays this way until I press cntrl c.

Ah, I tried the method in your link, my file is not opening correctly. Now I'm just not sure where to put my input file in xcode.

Code:

infile  = fopen("c:\\hw3AndyFoxInput.dat", "r");

Then just put it on your C drive.

Originally Posted by Fox101

I've been trying many things for the past day, and from what I can tell is that it is not even reaching the main function. The printf("hello"); is not printing, which is the first thing in the main function.

That is probably only happening because you forgot to put '\n' at the end of the string. The program crashed before it could flush the output buffer, so you never saw the message. It doesn't mean it's crashing before main().

Also, what exactly is the purpose of the ZEROI, ONEI, and TWOI macros? What is the point? Were you planning on changing the value of two?

We are not allowed to use hard coded numbers. Our prof wants every number to be defined in the constants file.

*The program now runs through main now on the unix server, just cant figure out where to put the input file on xcode.*

Originally Posted by Fox101

*The program now runs through main now on the unix server, just cant figure out where to put the input file on xcode.*

But: you're specifiying no path whatsoever when you open the file, therefore your input file has to be right where you are. If there's a "project path" or something in XCode, go there; otherwise it's in the same directory as everything else.

Originally Posted by Fox101

We are not allowed to use hard coded numbers. Our prof wants every number to be defined in the constants file.

You're missing the point. Why is it called "TWOI"? The purpose of defining such constants is so you can easily change their values in the future. So imagine you change this constant to 3. Now you have:

Code:

#define TWOI 3

So the constant says "TWO" yet its value is 3. I hope you can see why that's silly. The problem is the name. The name should indicate what the value is for, not what its specific value is. Otherwise it defeats the point of even doing this.

EDIT: Also, the numbers "0" and "1" occur very commonly. There is nothing wrong with literally saying "0" or "1" when you need it, despite what your professor says.

Yeh, I know what you mean, however he subtracts points if I use 0 or 1 heh.

Originally Posted by tabstop

But: you're specifiying no path whatsoever when you open the file, therefore your input file has to be right where you are. If there's a "project path" or something in XCode, go there; otherwise it's in the same directory as everything else.

Its in the scource area with my constants and main.c file.

Is that where your executable is? If so, you're probably golden; and if you're not, try running it on the command line.

Originally Posted by Fox101

Yeh, I know what you mean, however he subtracts points if I use 0 or 1 heh.

I think what brewbuck is saying is that you should give the #define a more meaningful name.

What do you use 2 for? For example, if it was the maximum number of apples capable of fitting in a barrel or something, I would call it MAX_APPLES, not TWOI.