Fstream file size

Second we are writing some contents to the file. In the same way we can read the file content with help of the getline function in while loop. We have already package like ifstream and ofstream but they can either read and write the file, but what we do in case if we want to perform read and write the file? In the examples we are showing how we are creating an empty file and writing some contents on the file and then again reading the same file with printing all the contents of the file.

It has the ability to perform dual work like it can create a file and at the same time it allows you to write the contents on the file.

From this tutorial we saw the basic concept of the fstream and we saw about the syntax of it. We also focused on the working and some of the important advantages of using the concept of the fstream. We saw some of the important examples also. You may also have a look at the following articles to learn more —. Submit Next Question. By signing up, you agree to our Terms of Use and Privacy Policy. Forgot Password?

Why don't the commitee just make a function for that which everybody could use? Isn't it just that simple? Are there any hidden caveats? But why? It provides the building blocks then it's up to you to do whatever you want with them. It would be a complete waste of time to create a function to serve just this one specific use case.

Besides, a simple "getter" could easily mislead people into not realising that a file seek is involved, which may have ramifications for them in all sorts of cases. It's better to have people do this explicitly. LightnessRacesinOrbit: while I do understand what you mean, I still do not agree. Many other functions are also that primitive to serve their specific usecase, like get the length of a string. This is a pretty common operation to get the size of things to make a function for it.

I believe you do it as well in your code - provide a function to know the size of your own classes, if size has a meaning for them. There are also plenty of function that do a potentially long operation under the hood, like vector resizing for example.

LightnessRacesinOrbit, on most systems getting the file size by subtracting offests returned by tell's operations is a slower operation than just directly getting the size of the file which is stored somewhere in the inode or similar structure in the filesystem itself. So, whilst the fallback algorithm could be the one that uses seek's and tell's, an optimized implementation could work around that and provide a faster approach. How's that a bad thing?

Show 14 more comments. Community Bot 1 1 1 silver badge. Jobin Jobin 5, 5 5 gold badges 21 21 silver badges 24 24 bronze badges. I guess I'll continue to use stat. Like this: long begin, end; ifstream myfile "example. Tim Cooper k 36 36 gold badges silver badges bronze badges. Philip Philip 2 2 silver badges 8 8 bronze badges. You may want to use the more appropriate std::streampos instead of long as the latter may not support as large a range as the former - and streampos is more than just an integer.

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