# Configuring Qt

Installing Qt

Qt works pretty much out of the box for compiling and linking purposes. If you don't want to install it in the default directory (/usr/lib/Trolltech/Qt-xxx), use the following configure command (for example, for Qt 4.1.4):

```./configure -prefix /usr/lib/qt-4.1.4/
```

Environment Variables

For some Qt programs to work properly (designer, for example) you must have exported QTDIR and LD_LIBRARY_PATH like so:

```export QTDIR=/usr/lib/qt-4.1.4

export LD_LIBRARY_PATH=\$QTDIR/lib
```

```export PATH=\$QTDIR/bin:\$PATH
```

You may also want to specify your qmake make-spec so you don't need to use -spec. On windows, this is usually something like

```QMAKESPEC=c:\qt\4.3.1\mkspecs\win32-msvc2005
```

Note that the value must be an absolute path, not just the "win32-msvc2005" part.

Visual Studio Support

In order to make Qt support MS Visual Studio .NET 2005, an unofficial patch is required. Download the patch from sourceforge.net. Install Qt as follows:

• Unpack the qt open source sources qt-win-opensource-src-4.2.2.zip to C:\Qt\4.2.2.
• Unpack acs-4.2.2-patch1.zip into C:\Qt\4.2.2\.
• From within the Visual Studio Command Prompt, not from cmd.exe (Tools->Visual Studio 2005 Command Prompt from inside Visual Studio), call:
```       installpatch42.bat
qconfigure msvc2005
nmake
```
• If required, to start over, type
`nmake distclean`
and then re-run
`qconfigure.bat`
. (Note: you must not call configure.exe; rather use qconfigure.)