replace line in a file C++

Question

I\'m trying to find a way to replace a line, containing a string, in a file with a new line.

If the string is not present in the file, then append it to the file.

Answer 1

To replace the last two lines in your file:

• Use fopen() to open the file
• Get the current file position with fgetpos()
• Store always the last two file position and read line by line
• When you've reached the end of the file: The lower position is where you have to position to with fseek()
• Now you can fprintf() your new lines to the file and close it with fclose() afterwards.