第一次写shell脚本,记录一下,什么都不懂,先来一个最简单的demo练练手,记录一下遇到的问题。
#!/bin/bash
echo "input 3 nums: "
echo "the first num is "
read num1
echo "the second num is "
read num2
echo "the third num is "
read num3
if [ $num1 -gt $num2 ]
then
let min=$num2
else
let min=$num1
fi
if [ $num3 -le $min ]
then
let min=$num3
fi
echo "the min num is $min"
首先第一行
bash是目前用的最多的(我也没数据,我也没调查,看别人这么说我也就这么认为吧)
上边的read是从屏幕中获取值。运行情况如图所示:
还可以这么写:
echo "the first num is $1"
echo "the second num is $1"
echo "the third num is $3"
那么就这么运行:
./3num.sh 1 2 3
[] 里侧要加空格,不然会出错。
if [ $num1 -gt $num2 ]
等号=两边不能有空格,不然也会出错。(迷)
let min=$num3