Where does Visual Studio look for C++ header files?

I checked out a copy of a C++ application from SourceForge (HoboCopy, if you're curious) and tried to compile it.

Visual Studio tells me that it can't find a particular header file. I found the file in the source tree, but where do I need to put it, so that it will be found when compiling?

Are there special directories?

Visual Studio looks for headers in this order:

• In the current source directory.
• In the Additional Include Directories in the project properties (Project -> [project name] Properties, under C/C++ | General).
• In the Visual Studio C++ Include directories under Tools → Options → Projects and Solutions → VC++ Directories.
• In new versions of Visual Studio (2015+) the above option is deprecated and a list of default include directories is available at Project Properties → Configuration → VC++ Directories

In your case, add the directory that the header is to the project properties (Project Properties → Configuration → C/C++ → General → Additional Include Directories).

Actually, on my windows 10 with visual studio 2017 community, the path of the C++ header are:

1. C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.15.26726\include

2. C:\Program Files (x86)\Windows Kits\10\Include\10.0.17134.0\ucrt

The 1^st contains standard C++ headers such as <iostream>, <algorithm>. The 2^nd contains old C headers such as <stdio.h>, <string.h>. The version number can be different based on your software.

If the project came with a Visual Studio project file, then that should already be configured to find the headers for you. If not, you'll have to add the include file directory to the project settings by right-clicking the project and selecting Properties, clicking on "C/C++", and adding the directory containing the include files to the "Additional Include Directories" edit box.

There seems to be a bug in Visual Studio 2015 community. For a 64-bit project, the include folder isn't found unless it's in the win32 bit configuration Additional Include Folders list.

There exists a newer question what is hitting the problem better asking How do include paths work in Visual Studio?

There is getting revealed the way to do it in the newer versions of VisualStudio

• in the current project only (as the question is set here too) as well as
• for every new project as default

The second is the what the answer of Steve Wilkinson above explains, what is, as he supposed himself, not the what Microsoft would recommend.

To say it the shortway here: do it, but do it in the User-Directory at

> C:\Users\UserName\AppData\Local\Microsoft\MSBuild\v4.0

in the XML-file

> Microsoft.Cpp.Win32.user.props

and/or > Microsoft.Cpp.x64.user.props

and not in the C:\program files - directory, where the unmodified Factory-File of Microsoft is expected to reside.

Then you do it the way as VisualStudio is doing it too and everything is regular.

For more info why to do it alike, see my answer there.

Tried to add this as a comment to Rob Prouse's posting, but the lack of formatting made it unintelligible.

In Visual Studio 2010, the "Tools | Options | Projects and Solutions | VC++ Directories" dialog reports that "VC++ Directories editing in Tools > Options has been deprecated", proposing that you use the rather counter-intuitive Property Manager.

If you really, really want to update the default $(IncludePath), you have to hack the appropriate entry in one of the XML files:

> \Program Files > (x86)\MSBuild\Microsoft.Cpp\v4.0\Platforms\Win32\PlatformToolsets\v100\Microsoft.Cpp.Win32.v100.props

or

> \Program Files > (x86)\MSBuild\Microsoft.Cpp\v4.0\Platforms\x64\PlatformToolsets\v100\Microsoft.Cpp.X64.v100.props

(Probably not Microsoft-recommended.)

It looks for files in the directory mentioned in options" cwd, you can include all sub directory under a path as shown below.

• it will create a single output file.
• it will compile all files together in the directory specified in cwd

project Structure:

moduelTest

-header_files
    - util.h
-source_files
    - util.c
    - main.c