Linux系统编译Libevent库

1 编写编译脚本

vim build.sh

#!/bin/bash

# 检查是否退出
set -e

# 下载编译代码
libevent_version=libevent-2.1.12-stable
wget -O ${libevent_version}.tar.gz https://github.com/libevent/libevent/releases/download/release-2.1.12-stable/libevent-2.1.12-stable.tar.gz
tar zxvf ${libevent_version}.tar.gz

# 新建编译目录
build_dir=${libevent_version}/build
if [ ! -d "$build_dir" ]; then
  echo "Create ${build_dir}..."
  mkdir -p ${build_dir}
fi

cd ${build_dir}

# 编译算法库
echo "Building Event ..."

cmake -D CMAKE_INSTALL_PREFIX=./install ..

make -j$(nproc)

# 安装算法库
make install

2 编写测试程序

2.1 移动编译库到指定路径

mv libevent-2.1.12-stable/build/install/lib ../../lib/libevent/

mv libevent-2.1.12-stable/build/install/include ../../lib/libevent/

cd ../../

2.2 修改Cmake的配置文件

vim lib/libevent/lib/cmake/libevent/LibeventTargets-shared.cmake

# The installation prefix configured by this project.
# set(_IMPORT_PREFIX "path/to/libevent-2.1.12-stable/build/install")
# Compute the installation prefix relative to this file.
get_filename_component(_IMPORT_PREFIX "${CMAKE_CURRENT_LIST_FILE}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
if(_IMPORT_PREFIX STREQUAL "/")
  set(_IMPORT_PREFIX "")
endif()

vim lib/libevent/lib/cmake/libevent/LibeventTargets-static.cmake

# The installation prefix configured by this project.
# set(_IMPORT_PREFIX "path/to/libevent-2.1.12-stable/build/install")
# Compute the installation prefix relative to this file.
get_filename_component(_IMPORT_PREFIX "${CMAKE_CURRENT_LIST_FILE}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
if(_IMPORT_PREFIX STREQUAL "/")
  set(_IMPORT_PREFIX "")
endif()

2.3 编写Cmake的编译文件

vim CMakeLists.txt

# 设置编译最小版本
cmake_minimum_required(VERSION 3.6.0)

# 设置目标工程名称
project(test)

# 设置编译工具参数
set(CMAKE_C_STANDARD 11)
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_BUILD_TYPE Release)

# 设置输出程序路径
set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/output)

# 添加第三方链接库
set(Libevent_DIR ${PROJECT_SOURCE_DIR}/lib/libevent/lib/cmake/libevent)
find_package(Libevent REQUIRED)
include_directories(${LIBEVENT_INCLUDE_DIRS})

message(STATUS "Libevent library status:")
message(STATUS "    version: ${LIBEVENT_VERSION}")
message(STATUS "    libraries: ${LIBEVENT_LIBRARIES}")
message(STATUS "    include path: ${LIBEVENT_INCLUDE_DIRS}")

# 生成可执行的程序
add_executable(${CMAKE_PROJECT_NAME} main.cpp)

# 程序相关的链接库
target_link_libraries(${CMAKE_PROJECT_NAME} ${LIBEVENT_LIBRARIES})

2.4 编写main.cpp测试程序

vim main.cpp

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <event2/event.h>

// 输入回调函数
void stdin_read_cb(evutil_socket_t fd, short events, void *arg)
{
    char buf[256];

    int len = read(fd, buf, sizeof(buf) - 1);
    if (len == -1)
    {
        perror("read error");
        return;
    }
    else if (len == 0)
    {
        printf("EOF\n");
        struct event_base *base = (struct event_base *)arg;
        event_base_loopbreak(base);
        return;
    }

    buf[len] = '\0';
    printf("Read from stdin: %s", buf);
}

// 定时回调函数
void timeout_cb(evutil_socket_t fd, short events, void *arg)
{
    printf("Timeout!\n");
}

int main(int argc, char **argv)
{
    // 创建事件对象
    struct event_base *base = event_base_new();
    if (!base)
    {
        fprintf(stderr, "Could not initialize libevent!\n");
        return 1;
    }

    // 创建监听事件
    struct event *stdin_event = event_new(base, fileno(stdin), EV_READ | EV_PERSIST, stdin_read_cb, (void *)base);
    if (!stdin_event)
    {
        fprintf(stderr, "Could not create stdin event!\n");
        event_base_free(base);

        return 1;
    }
    event_add(stdin_event, NULL);

    // 创建定时事件
    struct event *timeout_event = evtimer_new(base, timeout_cb, NULL);
    if (!timeout_event)
    {
        fprintf(stderr, "Could not create timeout event!\n");
        event_free(stdin_event);
        event_base_free(base);

        return 1;
    }

    // 设置五秒超时
    struct timeval timeout = {5, 0};
    evtimer_add(timeout_event, &timeout);

    // 进入事件循环
    event_base_dispatch(base);

    // 清理事件对象
    event_free(stdin_event);
    event_free(timeout_event);
    event_base_free(base);

    return 0;
}

2.5 编译运行测试程序

# 编译测试程序
rm -rf build && mkdir build && cd build && cmake .. && make

# 运行测试程序
./output/test

参考网址

  1. libevent
  2. Building and installing Libevent
posted @ 2024-06-26 20:08  盛夏夜  阅读(22)  评论(0)  编辑  收藏  举报