以备份 mysql 脚本为例，如下

#!/bin/bash
# 分隔符
str="-"# 定义分割线函数
FenGeLine() {## 获取屏幕宽度ScreenLen=$(stty size |awk '{print $2}')## 标题宽度TitleLen=$(echo -n $1 |wc -c)#echo $TitleLen## 左右分割线长度LineLen=$(((${ScreenLen} - ${TitleLen})/2))        # 一半长度，标题居中。if [ ${LineLen} -gt 0 ];then#echo $LineLen# 打印分割线yes ${str} |sed ''''${LineLen}'''q' |tr -d "\n" && echo -n $1 && yes ${str} |sed ''''${LineLen}'''q' |tr -d "\n" && echoelseecho "$1"fi}# 定义短选项和长选项
SHORT_OPTS="h"
LONG_OPTS="help,host:,user:,port:,password:,db:,backfile:,"# 解析命令行选项
PARSED_OPTS=$(getopt -o $SHORT_OPTS -l $LONG_OPTS -- "$@")
if [[ $? -ne 0 ]]; thenexit 1
fi# 将解析结果设置为位置参数
eval set -- "$PARSED_OPTS"# 处理选项
while true; docase "$1" in-h|--help)echo "Usage: $0 [options]"echo "  -h, --help      Show help"echo "  --host connect mysql ip address"echo "  --user connect mysql user"echo "  --port connect mysql port"echo "  --password connect mysql password"echo "  --db backup mysql database"echo "  --backfile backup file"shiftexit 0;;--host)host="$2"shift 2;;--user)user="$2"shift 2;;--port)port="$2"shift 2;;--password)password="$2"shift 2;;--db)db="$2"shift 2;;--backfile)backfile="$2"shift 2;;--)shiftbreak;;*)echo "Invalid option: $1"exit 1;;esac
done
host=${host:-localhost}
user=${user:-root}
port=${port:-3306}
password=${password:-123456}
backfile=${backfile:-/opt/mysql-${db}.sql}FenGeLine "host 默认值为 localhost"
FenGeLine "user 默认值为 root"FenGeLine "port 默认值为 3306"
FenGeLine "password 默认值为 123456"
FenGeLine "backfile 默认值为 /opt/mysql${db}.sql}"FenGeLine "传入的 host 为 $host"
FenGeLine "传入的 user 为 $user"
FenGeLine "传入的 port 为 $port"
FenGeLine "传入的 password 为 $password"
FenGeLine "传入的 db 为 $db"
FenGeLine "传入的 backfile 为 $backfile"if [ -z "$db" ];then
mysqldump  -h$host -u$user -P$port -p$password -A > $backfile
else
mysqldump  -h$host -u$user -P$port -p$password -B $db > $backfile
fi