05 函数

函数的定义

# 方式一
start () {
  echo "nginx start ....            [OK]"
  #return 0
}
stop () {
  echo "nginx stop ....              [FAIL]"
}

# 方式二
function start {
    echo "nginx start ....            [OK]"
}
# 函数的调用
start
stop

案例-编译安装nginx启动jio本

#!/usr/bin/env bash
nginx_install_doc=/usr/local/nginx
nginxd=${nginx_install_doc}/sbin/nginx
pid_file=${nginx_install_doc}/logs/nginx.pid

if [ -f $pid_file ]; then
nginx_pid=`cat ${pid_file}`
nginx_num=`ps -ef | grep ${nginx_pid} | grep -v "grep" | wc -l`
fi

if [ -f /etc/init.d/functions ]; then
  . /etc/init.d/functions
else
  echo "not found file /etc/init.d/functions"
  exit
fi

start() {
  if [ -f ${pid_file} ] && [ ${nginx_num} -ge 1 ]; then
    echo "nginx running..."
  else
    if [ -f $pid_file ] && [ $nginx_num -lt 1 ]; then
        rm -rf $pid_file
        echo " nginx start `daemon $nginxd` "
    fi
    action "nginx start" $nginxd
  fi
}

stop() {
if [ -f $pid_file ] && [ $nginx_num -ge 1 ]; then
    action "nginx stop" pkill nginx
else
    action "nginx stop" pkill nginx &> /dev/null
fi
}

restart() {
  stop
  sleep 1
  start
}

status() {
if [ -f $pid_file ] && [ $nginx_num -ge 1 ]; then
  echo "nginx running"
else
  echo "nginx stop"
fi
}

case $1 in
start)
  start
  ;;
stop)
  stop
  ;;
restart)
  restart
  ;;
status)
  status
  ;;
*)
  echo "错误输入，请重新执行"
  ;;
esac

#!/usr/bin/env bash
nginx_install_doc=/usr/local/nginx	#定义nginx安装目录变量
nginxd=${nginx_install_doc}/sbin/nginx	#定义nginx启动文件变量
pid_file=${nginx_install_doc}/logs/nginx.pid	#定义nginx的pid文件变量

if [ -f $pid_file ]; then	#如果这个pid文件存在
nginx_pid=`cat ${pid_file}`	#查看pid并赋值
nginx_num=`ps -ef | grep ${nginx_pid} | grep -v "grep" | wc -l`	#nginx进程数
fi

if [ -f /etc/init.d/functions ]; then	#调用内部函数
  . /etc/init.d/functions
else
  echo "not found file /etc/init.d/functions"
  exit
fi

start() {
  if [ -f ${pid_file} ] && [ ${nginx_num} -ge 1 ]; then	#如果pid文件存在，进程数大于等于1
    echo "nginx running..."	#说明nginx启动着
  else
    if [ -f $pid_file ] && [ $nginx_num -lt 1 ]; then	#如果pid文件存在，之前意外关闭
        rm -rf $pid_file	#删除pid文件
        echo " nginx start `daemon $nginxd` "	#启动
    fi
    action "nginx start" $nginxd	#其他情况，直接正常启动
  fi
}

stop() {
if [ -f $pid_file ] && [ $nginx_num -ge 1 ]; then	#如果pid文件存在，进程数大于等于1
    action "nginx stop" pkill nginx	#正常关闭
else
    action "nginx stop" pkill nginx &> /dev/null	#如果关闭着nginx，报错
fi
}

restart() {
  stop
  sleep 1
  start
}

status() {
if [ -f $pid_file ] && [ $nginx_num -ge 1 ]; then
  echo "nginx running"
else
  echo "nginx stop"
fi
}

case $1 in
start)
  start
  ;;
stop)
  stop
  ;;
restart)
  restart
  ;;
status)
  status
  ;;
*)
  echo "错误输入，请重新执行"
  ;;
esac

baim0手撸版

#!/bin/bash

if [ -f /etc/init.d/functions ]; then
  . /etc/init.d/functions
else
  echo "not found file /etc/init.d/functions"
  exit
fi
print_action() {
  if [ $2 -eq 0 ]; then
    action "$1" /bin/true
  else
    action "$1" /bin/false
  fi
}

start() {
  nginx -t
  if [ $? -eq 0 ]; then
    print_action "nginx配置文件正确" 0
    systemctl start nginx
    if [ $? -eq 0 ]; then
      print_action "Nginx 启动成功" 0
    else
      print_action "启动失败，请检查端口是否被占用"
    fi
  else
    print_action "nginx配置文件错误，请检查" 1
  fi

}

stop() {
  systemctl stop nginx
  if [ $? -eq 0 ]; then
    print_action "Nginx 停止成功" 0
  else
    print_action "Nginx 停止失败" 1
  fi
}

restart() {
  stop
  sleep 1
  start
}

status() {
  systemctl status nginx
  if [ $? -eq 0 ]; then
    print_action "正在查看状态" 0
  else
    print_action "Nginx未启动" 1
  fi
}

rpm -ql nginx >/dev/null
if [ $? -ne 0 ]; then
  PS3="Nginx尚未安装，是否安装>>:"
  select item in {"安装","不安装"}; do
    case $item in
    安装)
      cat >/etc/yum.repos.d/nginx.repo <<EOF
[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/7/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true
EOF
      yum clean all
      yum makecache
      yum install nginx -y
      print_action "Nginx安装成功，请重启脚本" 0
      exit
      ;;
    不安装)
      exit
      ;;
    esac

  done

else

  PS3="请输入对nginx的操作编号>>:"
  select item in start stop status restart; do
    case $item in
    "start")
      start
      ;;
    "stop")
      stop
      ;;
    "restart")
      restart
      ;;
    "status")
      status
      ;;
    *)
      print_action "请准确输入操作选项" 1
      ;;
    esac
  done
fi