Strange issue while trying to read from a file with fgets()

Question

I am trying to read from a file in C using fgets() however I have run into the following problem:

Although I can open the file successfully using fopen():

if ( file=fopen(filename, "r") == NULL )
{
    printf("Couldn't open specified file. Please try again.");
    exit(1);
}

I can't read anything from it. I am using the following loop, although nothing is printed and the execution terminates successfully.

while ( (fgets(inputLine, 1023, file)) != NULL)
{
    printf("Hello world");
}

This is independent of the actual filename, filesize or file contents. Nothing seems to work and nothing is shown up as an error in the debugger. A sample file I have tried is the following directly copied and pasted:

test.txt
#include <stdio.h>
int main ()
{
       printf("Hello World");
}

Do you have any guess as to why this is happening?

NOTE: I have taken the loop code from this S'O question so I guess it's right.

Answer 1

This is incorrect:

if ( file=fopen(filename, "r") == NULL )

Try:

if ( (file=fopen(filename, "r")) == NULL )

They way you have written it is equivalent to file = 0 (assuming the file is succesfully opened. If not, it is the same as file = 1). This is not what you want.