Save file with C fopen

Question

I did a program in C but it does not allow to save on c:\SomeDirectory\afile.txt

I'm using this:

FILE* m_hFile = fopen("c:\\SomeDirectory\\afile.txt", "a+t");
fprintf(m_hFile, "testing");
fclose(m_hFile);

Why that? Is there a defined folder I can save in?

SomeDirectory is previously created.

I'm using Windows 7 OS.

Answer 1

It sounds like perhaps "SomeDirectory" doesn't exist. You can create folders with C++ but you'll want to check if one's already there. Just calling the open command doesn't automagically create the folder. :)

Answer 2

If fopen encounters an error, it sets the errno variable indicating what error occurred. You can test this, or even simpler, use perror to print out an error message that will tell you what went wrong:

FILE* m_hFile = fopen("c:\\SomeDirectory\\afile.txt", "a+t");
if (m_hFile == NULL) {
  perror("fopen");
}