如何使用系统库创建静态库？

Question

I wrote a simple C++ program using ntl libraries. I try to create a static library from my program. I used these commands :

g++ -Wall -g -c base.cpp -o base.o
ar rcs libMyStaticLib.a *.o

libMyStaticLib.a was created successfully. But when I used libMyStaticLib.a in another project I get these error:

g++ -o main.out main.cpp -lMyStaticLib
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/libMyStaticLib.a(base.o): In function `NTL::Vec<NTL::GF2>::~Vec()':
/usr/local/include/NTL/vec_GF2.h:43: undefined reference to `NTL::WordVector::~WordVector()'

my main.cpp

#include <iostream>
#include </home/Qwer/test/base.h>

int main()
{
    baseInit();
    return 0;
}

I try to link ntl library while creating static library

ar rcs libMyStaticLib.a *.o -lntl 

But I get this error :

ar: two different operation options specified 

I want to try static library and use it in anoother project. How should I so this ?

Answer 1

Static libraries are nothing more that archives (that's what the ar program creates, and the .a suffix stands for) of object files. Linking with a static library is like linking with the objects files inside the archive.

That's why all other libraries that your static library depends on also must be linked:

$ g++ -o main.out main.cpp -lMyStaticLib -lntl