Unable to open a file with fopen()

Question

I've been trying to open a file and output text, but I keep getting errors. So I thought I would start at the very beginning and just try opening the file. This is my code:

#include <stdio.h>
#include <stdlib.h>
#define CORRECT_PARAMETERS 3

int main(void)
{
    FILE *file;
    file = fopen("TestFile1.txt", "r");
    if (file == NULL) {
        printf("Error");
    }
    fclose(file);
}

When I run the file, "Error" gets printed to the console and that's it. The TestFile1.txt is in the same location as my .exe. How do I fix this?

Answer 1

How are you running the file? Is it from the command line or from an IDE? The directory that your executable is in is not necessarily your working directory.

Try using the full path name in the fopen and see if that fixes it. If so, then the problem is as described.

For example:

file = fopen("c:\\MyDirectory\\TestFile1.txt", "r");
file = fopen("/full/path/to/TestFile1.txt", "r");

Or open up a command window and navigate to the directory where your executable is, then run it manually.

As an aside, you can insert a simple (for Windows or Linux/UNIX/BSD/etc respectively):

system ("cd")
system("pwd")

before the fopen to show which directory you're actually in.

Answer 2

Your executable's working directory is probably set to something other than the directory where it is saved. Check your IDE settings.