Question

# 在"set -e"之后出现的代码，一旦出现了返回值非零，整个脚本就会立即退出，注：set +e表示关闭，-e选项，set -e表示重新打开-e选项。
set -e 

# 表示shell脚本执行时如果遇到不存在的变量会报错并停止执行。默认不加-u参数的情况下，shell脚本遇到不存在的变量不会报错，会继续执行。
set -u 

set -o pipefail #设置了这个选项以后，包含管道命令的语句的返回值，会变成最后一个返回非零的管道命令的返回值。

#!/bin/bash
response=$(curl -sL -o /dev/null -w %{http_code} https://baidu.com)
if [[ $response -ge 200 && $response -le 299 ]] ;then 
    echo 'check point success'
else 
    echo 'check point fail'
fi

#!/bin/bash
# 配置文件中的配置项格式为key1=value1，一行一个配置项
while read line;do
    eval "$line"
done < /etc/openvpn/server/smtp.conf
echo $key1

#!/bin/bash
echo "选择以下功能:"
echo "   0) 功能0"
echo "   1) 功能1"
echo "   2) 功能2"
echo "   3) 功能3"
echo "   4) 功能4"
read -p "功能选项[4]: " option
until [[ -z "$option" || "$option" =~ ^[0-4]$ ]]; do
    read -p "$option为无效的选项，请重新输入功能选项: " option
done
case "$option" in
    0) 
        echo "功能0已执行!" 
    ;;
        1)
            echo "功能1已执行!" 
      exit
    ;;
        2)
            echo "功能2已执行!" 
            exit
        ;;
        3)
            echo "功能3已执行!"  
            exit
        ;;
        # 默认选项
        4|"")
            echo "功能4已执行!" 
            exit
        ;;
esac

{
echo "hahh"
echo "lalal"
} > /tmp/test

if [ -z ${var+x} ]; then 
    echo "var is unset"; 
else 
    echo "var is set to '$var'"; 
fi

参考：https://stackoverflow.com/questions/3601515/how-to-check-if-a-variable-is-set-in-bash

#!/bin/bash

# -z 选项用于检查变量是否为空字符串，如果是，则返回true
if [ -z "${VAR}" ]; then
    echo "VAR is empty"
fi

# -n 选项用于检查变量是否为非空字符串，如果是，则返回true。
if [ -n "${VAR}" ]; then
    echo "VAR is not empty"
fi

在测试变量是否为空时，最好使用双引号将变量括起来，以避免在变量为空时出现语法错误。

#!/bin/bash

a=60100
swap_seconds ()
{
    SEC=$1
    (( SEC < 60 )) && echo -e "持续时间: $SEC秒\c"
    (( SEC >= 60 && SEC < 3600 )) && echo -e "持续时间: $(( SEC / 60 ))分钟$(( SEC % 60 ))秒\c"
    (( SEC > 3600 )) && echo -e "持续时间: $(( SEC / 3600 ))小时$(( (SEC % 3600) / 60 ))分钟$(( (SEC % 3600) % 60 ))秒\c"
}

b=`swap_seconds $a`
echo $b

输出

持续时间: 16小时41分钟40秒

#!/bin/bash

main() {
    if [[ $# == 1 ]]; then
        case $1 in
        "-h")
            echo "脚本使用方法: "
            echo "  ./gitlab-pipeline.sh git仓库名1 git仓库名2 ... tag名(tag命名规则为: *-v加数字)"
            exit
            ;;
        "--help")
            echo "脚本使用方法: "
            echo "  ./gitlab-pipeline.sh git仓库名1 git仓库名2 ... tag名(tag命名规则为: *-v加数字)"
            exit
            ;;
        *)
            echo "参数错误！"
            exit
            ;;
        esac
    fi
}

main $*

# 第一步：判断镜像是否存在
if [ `docker images --format {{.Repository}}:{{.Tag}} |grep -Fx 192.168.1.7:32772/applications/$CI_PROJECT_NAME:${CI_COMMIT_SHORT_SHA};echo $?` -eq 0 ];then
   docker pull 192.168.1.7:32772/applications/$CI_PROJECT_NAME:$CI_COMMIT_SHORT_SHA ;
fi;
# 第二步：判断是否已经有重名的容器在运行或者处在其他状态。重名的，先删掉，在启动；不重名的直接启动
if [ `docker ps -a --format {{.Names}} |grep -Fx $CI_PROJECT_NAME > /dev/null ;echo $?` -eq 0 ] ;then
   docker rm -f $CI_PROJECT_NAME ;
   docker run -d --name $CI_PROJECT_NAME -p 30088:8080 192.168.1.7:32772/applications/$CI_PROJECT_NAME:$CI_COMMIT_SHORT_SHA ;
else
   docker run -d --name $CI_PROJECT_NAME -p 30088:8080 192.168.1.7:32772/applications/$CI_PROJECT_NAME:$CI_COMMIT_SHORT_SHA ;
fi;
# 第三步：循环五次判断容器的监控检测是否处于什么状态。健康状态就直接退出循环，不健康显示健康检查日志，正在启动的直接显示。处于其他状态的直接显示状态
n=0;
while true ;do
  container_state=`docker inspect --format='{{json .State.Health.Status}}' $CI_PROJECT_NAME`;
  case $container_state in
    '"starting"' )
      echo "应用容器正在启动！";
    ;;
    '"healthy"' )
      echo "应用容器已启动，状态健康！";
    break;
    ;;
    '"unhealthy"' )
      echo "应用容器健康检测失败！";
      docker inspect --format='{{json .State.Health.Log}}' $CI_PROJECT_NAME;
    ;;
    * )
      echo "未知的状态:$container_state";
    ;;
  esac;
  sleep 1s;
  n=$(($n+1));
  if [ $n -eq 5 ];
     then break ;
  fi ;
done

check_commands_exists() {
    need_commands=($*)
    no_commands=""
    for command in "${need_commands[@]}" ; do
        if ! command -v $command &> /dev/null; then
            no_commands+=" $command"
        fi
    done

    if [[ $no_commands ]]; then
        echo -e "\033[31m$no_commands 命令不存在，正在下载安装！\033[0m"
        os_type=$(uname -s)
        case "$os_type" in
            Linux*)
                os_distribution=$(lsb_release -si)
                if [ "$os_distribution" = "Ubuntu" ] || [ "$os_distribution" = "Debian" ]; then
                    apt install -y $no_commands >/dev/null 2>&1
                elif [ "$os_distribution" = "CentOS" ]; then
                    yum install -y $no_commands >/dev/null 2>&1
                elif [ "$os_distribution" = "Fedora" ]; then
                    dnf install -y $no_commands >/dev/null 2>&1
                fi
                if [[ $? == 0 ]] ;then
                    echo -e "\033[31m$no_commands 命令已安装！\033[0m"
                fi
                ;;
            Darwin*)
                brew install $no_commands >/dev/null 2>&1
                if [[ $? == 0 ]] ;then
                    echo -e "\033[31m$no_commands 命令已安装！\033[0m"
                fi
                ;;
            CYGWIN*|MINGW32*|MSYS*|MINGW*)
                echo -e "\033[31mWindows操作系统，请手动安装！\033[0m"
                ;;
            *)
                echo -e "\033[31m未知的操作系统\033[0m"
                return
                ;;
        esac
    fi
}
check_commands_exists jq pidof

check_network() {
    ping -c 4 114.114.114.114 >/dev/null
    if [ ! $? -eq 0 ]; then
        echo -e "\033[31mIP地址无法ping通，请检查网络连接！！！\033[0m"
        exit
    fi
    ping -c 4 www.baidu.com >/dev/null
    if [ ! $? -eq 0 ]; then
        echo -e "\033[31m域名无法Ping通，请检查DNS配置！！！\033[0m"
        exit
    fi
    curl -s --retry 2 --connect-timeout 2 www.baidu.com >/dev/null
    if [ ! $? -eq 0 ]; then
        echo -e "\033[31m域名无法Ping通，请检查DNS配置！！！\033[0m"
        exit
    fi
}

function sendDingDing(){
  Ding_Webhook_Token='钉钉机器人的WebHook Token'
  Ding_Webhook_keyword="可用作消息标题"
  send_result=$(curl -sS \
    -XPOST https://oapi.dingtalk.com/robot/send?access_token="$Ding_Webhook_Token" \
    -H 'Content-Type: application/json' \
    -d '{"msgtype": "markdown","markdown": {"title": "'$Ding_Webhook_Keyword'","text": "'"$*"'"},"at": {"isAtAll": true}}')
  if [ $(echo $send_result | jq -r '.errcode') -eq 0 ]; then
    echo "发送成功:  \n" $*" "
  else
    echo "发送失败:  \n" $*"\n"
    echo $send_result
  fi
}

sendDingDing  "$(date +"%F %H:%M:%S") 需要告警的消息"

.zshrc

function sendDingDing() {
  setopt no_nomatch
  Ding_Webhook_Token='钉钉机器人的WebHook Token'
  Ding_Webhook_Keyword='可用作消息标题'
  send_result=$(curl -sS \
    -XPOST https://oapi.dingtalk.com/robot/send?access_token="$Ding_Webhook_Token" \
    -H 'Content-Type: application/json' \
    -d '{"msgtype": "markdown","markdown": {"title": "'$Ding_Webhook_Keyword'","text": "'"$*"'"},"at": {"isAtAll": true}}')
  if [ $(echo $send_result | jq -r '.errcode') -eq 0 ]; then
    echo "发送成功:  \n" $*" "
  else
    echo "发送失败:  \n" $*"\n"
    echo $send_result
  fi
}
function kfdd() {
  sendDingDing "$(date +"%F %H:%M:%S") "$*" "
}

清理指定目录北备份文件，并保持指定个数。

function clean_backups (){
  if [ $# -gt 2 ];then
    echo "参数错误"
    exit 1
  else
    BAK_HOME=$1
    keepNum=$2
    fileNum=$(find ${BAK_HOME} -maxdepth 1 -type d -ctime -1 ! -path $BAK_HOME |wc -l)
    if [ $fileNum -gt $keepNum ] ;then
      find ${BAK_HOME} -maxdepth 1 -type d -ctime -1 ! -path $BAK_HOME | head -n `expr $fileNum - $keepNum` | xargs rm -rf
    fi
  fi
}
# 调用
clean_backups "./backups" 2

①并列格式化输出

tests='
a1a
b2b
c3c
d4d
e5e
f6f
g7g
h8h
i9i
j10j
k11k
'

count=1
colume=5 # 控制一行输出几列
for test in ${tests}; do
  printf "\e[;36m%-2s. %-10s\033[0m" "$count" "$test"
  if [ $((count % $colume)) -eq 0 ]; then
    echo ""
  fi
  ((count++))
done
# 针对文本变量的变量，bash中是"for test in ${tests}; do ... done" 。
#                 zsh中是"for test in ${(f)tests}; do ... done"。

# 格式化输出
1 . a1a       2 . b2b       3 . c3c       4 . d4d       5 . e5e
6 . f6f       7 . g7g       8 . h8h       9 . i9i       10. j10j
11. k11k