'Bus Error' using fread

This is a discussion on 'Bus Error' using fread within the C++ Programming forums, part of the General Programming Boards category; Hi, I have been struggling with this one for many hours now. Code compiles fine but when I run it ...

  1. #1
    Registered User no0b's Avatar
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    Jan 2009
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    'Bus Error' using fread

    Hi,

    I have been struggling with this one for many hours now. Code compiles fine but when I run it I get a 'bus error'. No more details are given by the program. I have narrowed it down to when I call fread.
    Code:
    #include <math.h>
    #include <iostream>
    #include <stdio.h>
    #include <string.h>
    #include <vector>
    #define _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES 
    using namespace std;
    
    char *wave;
    char *data;
    char *riff;
    unsigned long int length;
    unsigned int fs, numchannel, bytes, byterate, chunksize, vectsize;
    short nframes, fstart, fend, comp, bits;
    int toggle = 0;
    int *l, *r;
    
    ...........
    int main(){
    
    
    //open .wav file and verify header works fine problem occurs below
    
    ...
            int *r;
            int *l;
    	int left;
    	int right;
    	for(int i = 0; i <=50; i++){
    		
    		if(toggle%2 == 0){
    			fread(l, 4, 1, audio);
    			left = *l;
    			channelL.push_back(left);
    			cout <<channelL.at(left)<<endl;
    			
    		}
    		if (toggle%2 == 1){
    			fread(r, bytes, 1, audio);
    			right = *r;
    			channelR.push_back(right);
    			cout <<channelR.at(right)<<endl;
    			
    		}
    		toggle = toggle++;
    	}
    }
    It works fine if I just replace left and right with k and j and increment the counters. The problem is when I call fread. I am sure it is something so obvious.

  2. #2
    "I Win!" by U. Lose vart's Avatar
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    Rishon LeZion, Israel
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    variable l is not initialized pointer,so it points nowhere. And you still hope to sucessfully write to this unknown location? you extend your luck too greately with this hope.
    To be or not to be == true

  3. #3
    Registered User no0b's Avatar
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    Jan 2009
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    Thanks. I guess I didn't fully understand how to use pointers

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