（一）作用
  简单点说，有些页面元素是靠 js 动态加载的，那么我们在使用爬虫时，无法直接取到这些动态加载的 DOM 元素。而使用 SeimiAgent 工具以后，它会在我们取 DOM 元素之前，预先将 js 动态加载的部分先加载出来，这样我们就可以向取普通 DOM 元素一样进行处理。

（二）安装

1、先去 SeimiAgent 官网下载最新的工具包

2、centos 上操作

yum -y install gcc gcc-c++ make flex bison gperf ruby openssl-devel freetype-devel fontconfig-devel libicu-devel sqlite-devel libpng-devel libjpeg-devel

3、开启 8000 端口防火墙（供远程访问）
下面演示是基于 centos7 系统，不同于 centos6.5

//开启端口
firewall-cmd --zone=public --add-port=80/tcp --permanent

//重启防火墙
firewall-cmd --reload

4、

[root@localhost opt]# tar -zxvf seimiagent_linux_v1.3.1_x86_64.tar.gz 
seimiagent_v1.3.1/
seimiagent_v1.3.1/bin/
seimiagent_v1.3.1/bin/seimiagent
seimiagent_v1.3.1/README.md
seimiagent_v1.3.1/zh.md
seimiagent_v1.3.1/LICENSE.md
[root@localhost opt]# ls
seimiagent_linux_v1.3.1_x86_64.tar.gz  seimiagent_v1.3.1
[root@localhost opt]# cd seimiagent_v1.3.1/
[root@localhost seimiagent_v1.3.1]# ls
bin  LICENSE.md  README.md  zh.md
[root@localhost seimiagent_v1.3.1]# cd bin
[root@localhost bin]# ls
seimiagent
[root@localhost bin]# ./seimiagent -p 8000
./seimiagent: error while loading shared libraries: libfontconfig.so.1: cannot open shared object file: No such file or directory
[root@localhost bin]# yum install libfontconfig.so.1
Loaded plugins: fastestmirror
Determining fastest mirrors
 * base: mirrors.cqu.edu.cn
 * extras: mirrors.cqu.edu.cn
 * updates: mirrors.njupt.edu.cn
base                                                                                                                                                 | 3.6 kB  00:00:00     
extras                                                                                                                                               | 3.4 kB  00:00:00     
updates                                                                                                                                              | 3.4 kB  00:00:00     
extras/7/x86_64/primary_db     FAILED                                                                                                     ]  0.0 B/s |    0 B  --:--:-- ETA 
http://mirrors.cqu.edu.cn/CentOS/7.6.1810/extras/x86_64/repodata/43c71026fcdefd8e9770eeb304ad82573ce6c0364172a9e07ef088ead33394e6-primary.sqlite.bz2: [Errno 14] curl#56 - "Recv failure: Connection reset by peer"
Trying other mirror.
(1/4): base/7/x86_64/group_gz                                                                                                                        | 166 kB  00:00:00     
(2/4): updates/7/x86_64/primary_db                                                                                                                   | 3.3 MB  00:00:04     
(3/4): base/7/x86_64/primary_db                                                                                                                      | 6.0 MB  00:00:04     
(4/4): extras/7/x86_64/primary_db                        
[root@localhost bin]# ./seimiagent -p 8000
./seimiagent: error while loading shared libraries: libfontconfig.so.1: cannot open shared objec
[root@localhost lib]# cp  /usr/lib/libfontconfig.so.1 /usr/local/lib/libfontconfig.so.1

[root@localhost lib]# vim /etc/ld.so.conf.d/usr-libs.conf
/usr/local/lib

[root@localhost lib]# ldconfig
[root@localhost bin]# ./seimiagent -p 8000

下载 libfontconfig 安装包
http://rpmfind.net/linux/rpm2html/search.php?query=libfontconfig.so.1()(64bit)

[root@localhost opt]# ls
fontconfig-2.13.0-4.3.el7.x86_64.rpm  seimiagent_linux_v1.3.1_x86_64.tar.gz  seimiagent_v1.3.1
[root@localhost opt]# rpm -ivh fontconfig-2.13.0-4.3.el7.x86_64.rpm 
Preparing...                          ################################# [100%]
Updating / installing...
   1:fontconfig-2.13.0-4.3.el7        ################################# [100%]
[root@localhost opt]# cd seimiagent_v1.3.1/bin/
[root@localhost bin]# ./seimiagent 
[seimi] SeimiAgent started,listening on : 8000
[root@localhost bin]# nohup ./seimiagent &
[1] 4344
[root@localhost bin]# lsof -i:8000
COMMAND    PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
seimiagen 4344 root    4u  IPv4  42399      0t0  TCP *:irdmi (LISTEN)