On Windows, the fwrite function 0x0a is changed to 0x0d 0x0a.

When I use fwrite to write data to a file today (in Windows XP). When 0x0a is written, a 0x0d is always added before it. Later, I found that the cause of this problem is that when fwrite writes a file in text mode and encounters 0x0a, it will automatically add 0x0d to the front to generate a carriage return line break, because the default line break for Windows platforms is: 0x0d 0x0a. The solution is to open the file in binary mode and then write the file.

ProblematicCode:

Fopen (filename, "A + ");

Code to solve the problem:

fopen (filename, "A + B");