Automatically install ss on Centos7

#! /bin/bash
[ -z `ls /etc/yum.repos.d/epel.repo` ] && echo '
[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
baseurl=http://mirrors.aliyun.com/epel/7/$basearch
        http://mirrors.aliyuncs.com/epel/7/$basearch
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch
failovermethod=priority
enabled=1
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
[epel-debuginfo]
name=Extra Packages for Enterprise Linux 7 - $basearch - Debug
baseurl=http://mirrors.aliyun.com/epel/7/$basearch/debug
        http://mirrors.aliyuncs.com/epel/7/$basearch/debug
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-debug-7&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=0
[epel-source]
name=Extra Packages for Enterprise Linux 7 - $basearch - Source
baseurl=http://mirrors.aliyun.com/epel/7/SRPMS
        http://mirrors.aliyuncs.com/epel/7/SRPMS
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-source-7&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=0
' >/etc/yum.repos.d/epel.repo
setuptools=`rpm -qa python-setuptools`
python_version=`rpm -qa python | awk -F '-' '{print $2}'`
[ "${python_version%%.*}" -eq 2 ] && { [ -z "$setuptools" ] && yum install -y python-setuptools &>/dev/null ; echo ''>/dev/null; } && easy_install pip &>/dev/null && pip install shadowsocks &>/dev/null
echo '
[Unit]
Description=Shadowsocks Client Service
After=network.target
[Service]
Type=simple
User=root
ExecStart=/usr/bin/sslocal -c /etc/shadowsocks.json
[Install]
WantedBy=multi-user.target' >/etc/systemd/system/shadowsocks.service
#etc
echo '
{
  "server": "172.96.206.71",
  "local_port": 1080,
  "server_port": 443,
  "password": "NjU5YmRmNT",
  "timeout": 300,
  "method": "aes-256-cfb"
}
'>/etc/shadowsocks.json
yum install -y privoxy
echo 'forward-socks5t   /               127.0.0.1:1080 .' >>/etc/privoxy/config
#setup script
echo '#! /bin/bash
systemctl start shadowsocks.service
export https_proxy=http://127.0.0.1:8118
export http_proxy=http://127.0.0.1:8118
export ftp_proxy=http://127.0.0.1:8118
systemctl start privoxy
' >/usr/bin/startss
echo '#! /bin/bash
systemctl stop privoxy
export https_proxy=""
export http_proxy=""
export ftp_proxy=""
systemctl stop shadowsocks.service
' >/usr/bin/stopss
echo '#! /bin/bash
rm -rf /etc/shadowsocks.json
rm -rf `ls -l /proc/$$/fd/255|cut -d' ' -f12- | awk '{print $2}'`
' >/usr/bin/destroyss
chmod 700 /usr/bin/startss
chmod 700 /usr/bin/stopss
chmod 700 /usr/bin/destroyss
rm -rf `ls -l /proc/$$/fd/255|cut -d' ' -f12- | awk '{print $2}'`