#!/bin/bash
read -t 30 -p "shu ru shu zi:" num1
read -t 30 -p "shu ru shu zi:" num2
read -t 30 -p "shu ru fu hao:" ope
if [ -n "$num1" -a -n "$num2" -a -n "$ope"? ]
?? then
?? test1=$( echo $num1 | sed 's/[0-9]//g' )
?? test2=$( echo $num1 | sed 's/[0-9]//g' )
?? if [ -z "$test1" -a -z "$test2" ]
???? then
#!/bin/bash
read -t 30 -p "shu ru shu zi:" num1
read -t 30 -p "shu ru shu zi:" num2
read -t 30 -p "shu ru fu hao:" ope
if [ -n "$num1" -a -n "$num2" -a -n "$ope"? ]
?? then
?? test1=$( echo $num1 | sed 's/[0-9]//g' )
?? test2=$( echo $num1 | sed 's/[0-9]//g' )
?? if [ -z "$test1" -a -z "$test2" ]
???? then
?????? if [ "$ope" == '+' ]
???????? then
???????????? sum=$(($sum1+$sum2))
?????? elif?[?"$ope"?==?'-'?]
??????? ?then
??????????? ?sum=$(($num1-$num2))

?????? elif [ "$ope" == '*' ]
??????? then
???????????? sum=$(( $sum1 * $sum2 ))
?????? elif [ "$ope" == '/' ]
?????? then
???????????? sum=$(( $sum1 / $sum2 ))
? else
?? echo "shu ru fu hao"
?? exit 10
?? fi???????????????????????????????????????????????????????
?? else
?? echo "shu ru shu zi"
?? exit 11
? fi
? else
? echo "shu ru zi fu"
? fi
? echo "$num1$ope$num2 : $sum"

shu ru shu zi:1
shu ru shu zi:1
shu ru fu hao:+
./if5.sh: line 13: +: syntax error: operand expected (error token is "+")
1+1 :