This application failed to start because it could not find or load the Qt platform plugin “linuxfb“

[email protected]:~# ./untitled

This application failed to start because it could not find or load the Qt platform plugin "linuxfb".

原因是程序找不多linuxfb这个插件，配置下插件的查找路径就可以了

解决办法

export QTDIR=/usr
export QT_QPA_FONTDIR=$QTDIR/lib/fonts
export QT_QPA_PLATFORM_PLUGIN_PATH=$QTDIR/plugins/
export LD_LIBRARY_PATH=$QTDIR/lib:$LD_LIBRARY_PATH
export QT_QPA_PLATFORM=linuxfb:fb=/dev/fb0:size=800x600:mmSize=800x600:offset=0x0:tty=/dev/tty1
           

QT_QPA_PLATFORM_PLUGIN_PATH设置为Qt plugins的真实路径

不过，最好的办法是将qt库安装到正确目录。 这个目录是编译qt时指定或默认的安装目录。执行qmake -v命令，会显示qt应该安装在什么位置，把一套qt放过去，像我这里把上面的QTDIR设置成/usr/local/qt-5.4.2就好了。

[email protected]:~/work/openssl-1.0.2e$ /usr/local/qt-5.4.2/bin/qmake  -v
QMake version 3.0
Using Qt version 5.4.2 in /usr/local/qt-5.4.2/lib
           

参考：http://www.zhimengzhe.com/linux/288929.html

https://stackoverflow.com/questions/15259900/qt-creator-2-6-2-and-qt-4-8-4-qt-version-is-not-properly-installed