运行时检查失败＃2-变量'seqA'周围的堆栈已损坏

Question

i have windows 8 with vs2010, when i run this part of program this error shown: Run-Time Check Failure #2 - Stack around the variable 'seqA' was corrupted. ..............................................................................

#include <iostream.h>
#include <stdio.h>
#include <string>
#include<stdlib.h>
#include <fstream>
using namespace std;

    int main(){
int lenA = 0;
int lenB = 0;
FILE * fileA, * fileB;
char holder;
char seqA[10], seqB[10];

/*open first file*/
fileA=fopen("c:\\str1.fa", "r");

/*check to see if it opened okay*/
if(fileA == NULL) {
    perror ("Error opening 'str1.fa'\n");
    exit(EXIT_FAILURE);
}


/*open second file*/
fileB = fopen("c:\\str2.fa", "r");

/*check to see if it opened okay*/
if(fileB == NULL) {
    perror ("Error opening 'str1.fa'\n");
    exit(EXIT_FAILURE);
}

/*measure file1 length*/
while(fgetc(fileA) != EOF) {
    holder = fgetc(fileA);
    seqA[lenA]=holder;
    lenA++;
}
lenA--;

fclose(fileA);

holder='0';

/*measure file2 length*/
while(fgetc(fileB) != EOF) {
    holder = fgetc(fileB);
    seqB[lenB]=holder;
    lenB++;
}
lenB--;

fclose(fileB);  

link picture of this error.

Answer 1

This: seqB[lenA]=holder; lenA++; seqB[lenA]=holder; lenA++; will overflow unless your file is very short (10 characters or less (and likewise with seqB and lenB .

Answer 2

You initialized seqA and SeqB to 10 chars. I think the file is bigger than that and you are corrupting the stack by writing outside the sequence array. Allocate more memory to the sequence.

Answer 3

Your method for reading file isn't safe. You have a variable which is a char [10] but what happend if your file have more than 10 character? You'll write in the memory using seqA[10] = holder; (for exemple) and by the way you'll overwrite the stack. I think that is the problem. A solution is to break after 10 character readed or use a dynamically allocated array and reallocate it when his size is reached.