Fstream copy file

I have a question: does the copy method account for the current writing position of the stringstream? If I use tellp 8 , then use copy will it still work, or will it write from the beginning of the stringstream? EDIT: I tried it out formyself and it seems to work great. Thank you! Still, I like pinkfloydx's solution made into a complete example by Andre better.

Ben Voigt: So do I. I actually didn't know you could do that so easily. My testing shows a slight difference.

On a 50k file, copied 10 times each with both methods, his averaged 1. Show 1 more comment. Roy Shilkrot Roy Shilkrot 1, 22 22 silver badges 16 16 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. NET etc. Share More sharing options Followers 0. Blackout Posted December 7, Posted December 7, Can someone tell me how to copy a binary file using fstream.

In the below example first we are getting or creating a file, we can give any name to file which we are creating here. 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. The tellg member function can get the position number of the character the pointer is pointing to.

When the file is just opened, tellg will return 0 for the first character. After some reading, tellg would return a number like 27 in the example above.

The following code displays two position numbers and their corresponding characters, using the tellg function:. The above seekg function is overloaded for the input stream as:. So, if the internal pointer is pointing to the character at position 27 by counting the beginning from 0, then.

Takes and maintains the pointer at the beginning of the file; to point to the first character of the file, with an offset of 0. Note that the single space is counted as one character. The following code illustrates the use of the function, at the current position, with a negative and positive offset:.

In the classical approach, characters are read one by one and changed one by one. All the characters of the file are read into a char array. The array is modified using the character positions that correspond to the positions in the file. After that, the array content is sent back to the file to replace the old content. The modification is typically done while the file is being read.

To replace a character, simply replace it in the array. To delete a character, bring down all the characters ahead in one place. To insert a character, shift all the characters ahead by one place and insert. In order to accomplish this, the size of the array should be estimated to be at least the number of all the final characters.

In order to carry out the following task, back up the file, doc1. In the following code sample, when a character is read, it is checked, before it is edited. The stream object then has to be opened for input or output or both. To append text to the file, the stream has to be opened for appending.