比較2個數的大小

#！/bin/sh

比較2個數的大小

#by zkg 2019-07-31
read -p "please input tow num:" num1 num2
a=$num1
b=$num2

#必須是2個數
[ -z "$a" -o -z "$b" ]&&{
echo "USAGE:NUM1 NUM2"
exit 1
}

#必須是2個參數是整數
[ "echo "$a"|sed -r 's/[^0-9]//g'" = "$a" ]||{
echo "must be int"
exit 2
}
[ "echo "$b"|sed -r 's/[^0-9]//g'" = "$b" ]||{
echo "must be int"
exit 2
}

#比較兩個數的大小
[ "$a" -eq "$b" ]&&{
echo "$a=$b"
exit 0
}
[ "$a" -gt "$b" ]&&{
echo "$a>$b"
exit 0
}
[ "$a" -lt "$b" ]&&{
echo "$a<$b"
exit 0
}