Shell脚本记录

Shell For循环

类c语言

for ((i=1; i<=100; i ++))  
do  
    echo $i  
done  

in使用

for i in {1..100...2}  
do  
    echo $i  
done

2步一跳

seq使用

for i in `seq 1 100`  
do  
    echo $i  
done  

对于我目前这些就够用，更多shell循环：https://blog.youkuaiyun.com/taiyang1987912/article/details/38929069

计算shell脚本的执行时间

#!/bin/bash  
start_time=`date --date='0 days ago' "+%Y-%m-%d %H:%M:%S"`  

#this is your shell script   
sleep 18  

##############  
finish_time=`date --date='0 days ago' "+%Y-%m-%d %H:%M:%S"`  

duration=$(($(($(date +%s -d "$finish_time")-$(date +%s -d "$start_time")))))  

echo "this shell script execution duration: $duration"  

Shell数组

https://blog.youkuaiyun.com/qmhball/article/details/56293069

脚本获取当前绝对路径

work_path=$(dirname $(readlink -f $0))
echo $work_path

判断字符串为空

if [ -z "$str" ]; then

    echo "empty string"

fi

判断文件是否存在

if [ -f /home/builder/.profile ]; then

    echo "File exists;"

fi