Debug Assertion Failed VS2010

Question

I'm making a very simple program to read in from a text file and print the contents. When the file finishes compiling I keep getting this debug assertion failed message!

I've never seen it before and can't seem to find any solutions.

(It won't let me post an image because my rep isn't high enough!)

The code

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

int main()
{
 FILE *file = fopen("C:\\Users\Kyne\\Desktop\\AdvProgrammingAssignment\\employees.txt", "r");
 char c;

do
{
    c = fgetc(file);
    printf("%c", c);
}
while(c != EOF);

fclose(file);
return 0;

printf("\n\n\n");
system("pause");
}

when does it cause debug assertion? Also try stepping through your code with debugger — Creris, Apr 20 '15 at 15:09
C:\\Users\Kyne\\Desktop\\ There is a missing backslash after Users — Ganesh R., Apr 20 '15 at 15:11

score 1 · Accepted Answer · answered Apr 20 '15 at 15:21

Step through your code using the debugger to find the line that is causing the debug assertion, and check to see if the file is opened.

In the line

FILE *file = fopen("C:\\Users\Kyne\\Desktop\\AdvProgrammingAssignment\\employees.txt", "r");

it looks like you missed a '\' before 'Kyne' so it should be

FILE *file = fopen("C:\\Users\\Kyne\\Desktop\\AdvProgrammingAssignment\\employees.txt", "r");

There are other issues like calling return 0; before the end of the main block.

score 0 · Answer 2 · answered Apr 20 '15 at 15:11

I don't see any checks if file was opened properly. Also, I would check for EOF mark before first read - use while and feof() instead. Finally, these lines:

printf("\n\n\n");
system("pause");

will never get called, as you do return 0 after fclose() - move it [return 0] to the end.

Try this:

int main()
{
    FILE *file = fopen("C:\\Users\\Kyne\\Desktop\\AdvProgrammingAssignment\\employees.txt", "r");

    if(!file)
    {
        printf("File could not be opened!\n");
        return -1;
    }

    while(!feof(file))
    {
        char c = fgetc(file);
        printf("%c", c);
    }

    fclose(file);

    printf("\n\n\n");
    system("pause");

    return 0;
}

Most likely, your error originated in using FILE* set to NULL - you have one slash missing after \\Users, so file probably was never opened and fopen() was constantly returning NULL.

Debug Assertion Failed VS2010

2 Answers2