Because of many unresolved problems concerning stdio.h with codeblocks use VS, xcode or Qt if possible and get on with some programming. codeblocks is unsupported rubbish.
Will it have the same problem with iostream in C++?
I used to use Code Blocks before I started using Windows 10 and it worked like a charm with stdio.h. I'd already been using Visual Studio Community 2015 on Windows 10, though. I just wanted to also have Code Blocks so I could cross-platform programs. Visual Studio only has an option for Windows 10 or earlier. I do have extensions in VS for cross-platform code, but I don't know if they'll work as I intend.