read a
read b
printf "%s\n" $a{+,-,*,/}"$b"|bc
read a
read b
if [ $a -gt $b ]
then
echo "X is greater than Y"
elif [ $a -eq $b ]
then
echo "X is equal to Y"
else
echo "X is less than Y"
fi
- 字符串比较 需要注意空格 == 两边均需要空格
[[]] 中支持字符串的匹配 比如$answer = ~ an.*er [[]]匹配字符串或者通配符的时候不需要引号。&& || <和>能够正常存在于[[]]结构。
read answer
if [[ $answer == "y"||$answer == "Y" ]]
then
echo "YES"
else
echo "NO"
fi
read A
printf "%.3f" $(echo "$A" | bc -l)
read num
echo $num | bc -l | xargs printf "%.3f"
- 计算平均数,注意数组如何定义arr=() ${var// /+}意为将所有的 空格替换为+ ${var/ /+}意为将第一个空格替换为+
read n
arr=($(cat))
arr=${arr[*]}
printf "%.3f" `echo "$((${arr// /+}))"/$n|bc-l`