c - 如何在C中调用动态库？

Question

操作系统:Ubuntu 14.04 (值得信赖的塔尔)

编写两个 .c 文件，分别命名为 dtest1.c 和 dtest2.c。

文件dtest1.c

int p = 2;

void print()
{
    printf("this is the first DLL test!\n");
}

文件dtest2.c

int p = 3;

void print()
{
    printf("this is the second DLL test!\n");
}

然后，编译它们得到两个名为dtest1.so和dtest2.so的文件:

gcc -O -fpic -shared -o dtest1.so dtest1.c
gcc -O -fpic -shared -o dtest2.so dtest2.c

编写一个名为dtest3.c的.c文件。

文件dtest3.c

#include "dtest1.so"

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

到目前为止，一切都很好。没有任何错误(只有警告)。

然后:

gcc -o dtest3 dtest3.c dtest1.so

错误:

In file included from dtest3.c:1:0:
dtest1.so:17:1: warning: null character(s) ignored [enabled by default]
dtest1.so:17:2: error: stray ‘\260’ in program
   ......
   ......    /*omit too many similar information */
dtest1.so:18:2: error: stray ‘\212’ in program
dtest1.so:18:2: error: stray ‘\1’ in program
In file included from dtest3.c:1:0:
dtest1.so:18:956: warning: null character(s) ignored [enabled by default]
In file included from dtest3.c:1:0:
dtest1.so:18:2: error: stray ‘\244’ in program
dtest1.so:18:2: error: stray ‘\1’ in program
In file included from dtest3.c:1:0:
dtest1.so:18:980: warning: null character(s) ignored [enabled by default]
dtest1.so:18:982: warning: null character(s) preserved in literal [enabled by default]
dtest1.so:18:982: warning: missing terminating " character [enabled by default]
In file included from dtest3.c:1:0:
dtest1.so:18:2: error: missing terminating " character

这有什么问题吗？

Answer 1

库是编译后的代码，而不是(文本)源代码。 #include 只是插入给定文件的内容，因此它应该是源代码。您必须通过将库作为参数传递给链接器来链接库。

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