未定义的引用gdImageString

Question

我想编译一个名为Contrafold的程序，我需要两个库（libgd和libpng），问题是链接库，但它通过我一个未定义的引用错误，我不知道为什么....我的代码编译为后续：

g++ -O3 -DNDEBUG -W -pipe -Wundef -Winline --param large-function-growth=100000 -Wall EncapsulatedPostScript.o PlotRNA.o SStruct.o Utilities.o -o plot_rna -lm -L/path-to-library/libgd.a -L/path-to-library/libpng16.a 

，并且错误是：

PlotRNA.cpp:(.text+0x189e): undefined reference to `gdImageString' 
PlotRNA.cpp:(.text+0x1a34): undefined reference to `gdImageFilledArc' 
PlotRNA.cpp:(.text+0x1a79): undefined reference to `gdImageSetAntiAliased' 
PlotRNA.cpp:(.text+0x1ad6): undefined reference to `gdImageChar' 
PlotRNA.cpp:(.text+0x1c76): undefined reference to `gdImageLine' 
PlotRNA.cpp:(.text+0x1fce): undefined reference to `gdImageString' 
PlotRNA.cpp:(.text+0x2036): undefined reference to `gdImageCreateTrueColor' 
PlotRNA.cpp:(.text+0x2079): undefined reference to `gdImageColorAllocate' 
PlotRNA.cpp:(.text+0x2093): undefined reference to `gdImageColorAllocate' 
PlotRNA.cpp:(.text+0x213a): undefined reference to `gdImageColorAllocate' 
PlotRNA.cpp:(.text+0x217d): undefined reference to `gdImageFilledRectangle' 
PlotRNA.cpp:(.text+0x2182): undefined reference to `gdFontGetMediumBold' 
PlotRNA.cpp:(.text+0x218f): undefined reference to `gdFontGetSmall' 
PlotRNA.cpp:(.text+0x223b): undefined reference to `gdImagePng' 
PlotRNA.cpp:(.text+0x2250): undefined reference to `gdImageDestroy' 

任何选项？

Answer 1

也许你忘了添加含GD *函数库链接：-lgd