Thread: Removing *Unchanged* Output File (ofstream) :: C++

Hi.

I am working on an interesting and simple problem. A program I am working on initializes an ofstream object. It does calculations (arbitrary) and writes to the output file. The problem is sometimes it writes new data and sometimes it does not. I am currently using a bool to make sure if it does not write new data, then it should remove the output file when it finishes. There is one false assumption. I am assuming the output file is always empty. That is not true because the output file is openned with "ios::app," which is appending mode. The program sometimes remove files that are not empty.

I tried using the empty() function, but it does not work for an ofstream object. I would like to know the best way to check to make sure an ofstream object is *empty* return from the a end of class or before the program closes.

Thanks,
Kuphryn

Hmm try this code to check if an ofstream object is empty

ofstream output;
// do stuff here

filebuf * FileBuffer = output.rdbuf();
if ( FileBuffer->sgetc() == EOF )
{
//the first char is EOF so the file is empty
}
else
{
//file is not empty
}
FileBuffer = NULL;
if you delete the file make sure do set filebuffer to null


I dont have a compiler to test that out right now, but i think it should work

Okay. Thanks.

I implemented the seekp() and tellp() method. It works flawlessly.

Kuphryn