Apache Avro C安装 [英] Apache Avro C Installation

问题描述

我正在开发一个项目，并且正在使用Apache Avro.我已经下载了Apache Avro for C，并且按照提供的说明进行了安装，以便将其安装在系统上(Ubuntu Linux v14.04).安装后，我在/include 目录下有一些头文件，在/lib 目录下有一些库.所有这些都是从Apache Avro安装的.

I am working on a project and I am using Apache Avro. I have downloaded Apache Avro for C and I followed the instructions provided in order to install it on my system (Ubuntu Linux v14.04). After the installation, I have some header files under the /include directory and some libraries under /lib directory. All of those are the ones that were installed from Apache Avro.

至此，我已经创建了如下的C源文件:

At this point, I have created my C source files which are as follows:

1)socket_client.h:

1) socket_client.h :

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include "avro.h"
#include <errno.h>
#include <stdint.h>

#ifndef SOCKET_CLIENT_H_
#define SOCKET_CLIENT_H_

void init_schema(void);

int client_execution_connect(char* ip_addr, int port, char* type);

#endif /* SOCKET_CLIENT_H_ */

2)socket_client.c:

2) socket_client.c :

#include <stdio.h>
#include "socket_client.h"

avro_schema_t bigpeer_schema;
void init_schema(void)
{
    if( avro_schema_from_json_literal(BIG_PEER_SCHEMA, &bigpeer_schema) )
    {
        printf("Unable to parse big_peer schema");
        exit(EXIT_FAILURE);
    }
}
int client_execution_connect(char* ip_addr, int port, char* type)
{
    ...
}

和一个测试主文件.另外，我创建了以下makefile来编译我的代码:

and a test main file. Also, I have created the following makefile to compile my code:

CC=gcc
CFLAGS=-c -Wall
LDFLAGS=
SOURCES=test_main.c socket_client.c
OBJECTS=$(SOURCES:.c=.o)
EXECUTABLE=avro_test
INC_PATH=/include/avro/

INC=-I/include
LIB=-L/lib

all: $(SOURCES) $(EXECUTABLE)

$(EXECUTABLE): $(OBJECTS)
    $(CC) $(LDFLAGS) $(LIB) $(OBJECTS) -o $@

.c.o:
    $(CC) $(INC) $(CFLAGS) $< -o $@

clean:
    rm -rf *.o avro_test

但是，当我尝试进行申请时，会得到以下信息:

But, when I try to make my application, I get the following:

nick@rethimno:~/Downloads/AvroClient$ make
gcc -I/include -c -Wall test_main.c -o test_main.o
test_main.c: In function ‘main’:
test_main.c:22:6: warning: unused variable ‘port’ [-Wunused-variable]
  int port = atoi(argv[2]);
      ^
test_main.c:15:8: warning: unused variable ‘type’ [-Wunused-variable]
   char* type = "db_node";
        ^
gcc -I/include -c -Wall socket_client.c -o socket_client.o
gcc  -L/lib test_main.o socket_client.o -o avro_test
socket_client.o: In function `init_schema':
socket_client.c:(.text+0x14): undefined reference to `avro_schema_from_json_length'
collect2: error: ld returned 1 exit status
make: *** [avro_test] Error 1

我做错了什么?我不确定Apache Avro的库是否正确加载.

What am I doing wrong? I am not quite certain if the libraries of Apache Avro are loaded properly.

谢谢你，尼克

推荐答案

您包括了Avro标头，但没有将最终的可执行文件链接到Avro库.假设您在 lib 目录(其中 *.so 是共享目录)中具有 libavro.so 或 libavro.a 库，而 *.a 是静态库)，则需要更改Makefile的这一行:

You are including the Avro headers, but you aren't linking your final executable against the Avro libraries. Assuming you have libavro.so or libavro.a in the lib directory (where *.so is a shared library, and *.a is a static library), you will want to change this line of your Makefile:

LDFLAGS = -lavro

请注意，如果库二进制文件被称为 libavro.so 或 libavro.a 以外的名称，则需要更改 -lavro 值进行匹配.另请注意，某些软件包可能包含多个您需要链接的共享库.我对Apache Avro不够熟悉，无法说出是这种情况.您通常只需要查看并查看 lib 目录中的内容.

Note that, if the library binary is called something other than libavro.so or libavro.a, you'll need to change the -lavro value to match. Also note that certain packages can contain more than one shared library you will need to link against. I am not familiar enough with Apache Avro to say whether or not this is the case; you will mostly just need to look and see what is inside your lib directory.

您可以在 GCC文档中了解有关链接到库的更多信息.

You can more information about linking to libraries in the GCC documentation.

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