问题描述
我想用C ++编写一个Apache模块.我尝试了一个非常准系统的模块来开始:
I'd like to write an Apache module in C++. I tried a very barebones module to start:
#include "httpd.h"
#include "http_core.h"
#include "http_protocol.h"
#include "http_request.h"
static void register_hooks(apr_pool_t *pool);
static int example_handler(request_rec *r);
extern "C" module example_module;
module AP_MODULE_DECLARE_DATA example_module = {
STANDARD20_MODULE_STUFF, NULL, NULL, NULL, NULL, NULL, register_hooks
};
static void register_hooks(apr_pool_t *pool) {
ap_hook_handler(example_handler, NULL, NULL, APR_HOOK_LAST);
}
static int example_handler(request_rec *r) {
if (!r->handler || strcmp(r->handler, "example"))
return (DECLINED);
ap_set_content_type(r, "text/plain");
ap_rputs("Hello, world!", r);
return OK;
}
使用apxs
进行编译似乎可以正常工作,使用:
Compiling with apxs
seems to work just fine, using:
apxs -i -n example_module -c mod_example.cpp
但是,当我尝试启动httpd时,出现错误.我插入了一些新行以使其更清晰.
However, when I try to start httpd, I get an error. I've inserted some newlines to make it more legible.
httpd: Syntax error on line 56 of /etc/httpd/conf/httpd.conf:
Syntax error on line 1 of /etc/httpd/conf.modules.d/20-mod_example.conf:
Can't locate API module structure `example_module' in file /etc/httpd/modules/mod_example.so:
/etc/httpd/modules/mod_example.so: undefined symbol: example_module
实际上,我可以用objdump -t
确认在mod_example.so
中没有名为example_module
的符号.我觉得这特别令人困惑,因为如果我手动编译
Indeed, I can confirm with objdump -t
that there is no symbol named example_module
in mod_example.so
. I find this especially confusing because if I manually compile with
gcc -shared -fPIC -DPIC -o mod_example.so `pkg-config --cflags apr-1` -I/usr/include/httpd mod_example.cpp
(模仿我在apxs
内部看到的libtool
命令),然后objdump -t
确实在mod_example.so
中显示了example_module
符号.
(which mimics the command I see libtool
running from inside apxs
), then objdump -t
does indeed show an example_module
symbol in mod_example.so
.
有什么作用?为什么example_module
没有出现在我的.so
中?我该怎么解决?
What gives? Why doesn't example_module
appear in my .so
? What can I do to fix it?
推荐答案
解决此问题的一种方法是将cpp文件编译为目标文件,然后将该目标文件传递给apxs工具.例如:
One approach to solve this problem would be to compile the cpp file to object file and then pass that object file to the apxs tool. For example:
g++ `pkg-config --cflags apr-1` -fPIC -DPIC -c mod_example.cpp
apxs -i -n example_module `pkg-config --libs apr-1` -c mod_example.o
这篇关于如何用C ++编写Apache模块?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!