hellopasswd

shell中的case判断

• 格式case 变量名in value1) command ;; value2) command ;; *) command ;; easc
• 在case程序中，可以在条件中使用|，表示或的意思，比如2|3 command ;;

      1 #!/bin/bash2 read -p "Please input a number:" n3 if [ -z $n ]4 then5     echo "Please input a number."6     exit 17 fi8 n1=`echo $n|sed 's/[0-9]//g'`9 if [ ! -z $n1 ]10 then11     echo "Please input a number."12     exit 113 #elif [ $n -lt 0] || [ $n -gt 100 ]14 #then15 #    echo "The number range is 0-100."16 #    exit 117 fi18 if [ $n -lt 60 ] && [ $n -ge 0 ]19 then20     tag=121 elif [ $n -ge 60 ] && [$n -lt 80 ]22 then23     tag=224 elif [ $n -ge 80 ] && [ $n -lt 90 ]25 then26     tag=327 elif [ $n -ge 90 ] && [ $n -le 100 ]28 then 29     tag=430 else31     tag=032 fi33 case $tag in34     1)35         echo "1"36     ;;37     2)38         echo "2"39     ;;40     3|4)41         echo "3"42     ;;43     *)44         echo "The number range is 0-100."45     ;;46 esac

[root@localhost shell]# sh -x 1.sh
+ read -p 'Please input a number:' n
Please input a number:101
+ '[' -z 101 ']'
++ sed 's/[0-9]//g'
++ echo 101
+ n1=
+ '[' '!' -z ']'
+ '[' 101 -lt 60 ']'
+ '[' 101 -ge 60 ']'
+ '[' 101 -lt 80 ']'
+ '[' 101 -ge 80 ']'
+ '[' 101 -lt 90 ']'
+ '[' 101 -ge 90 ']'
+ '[' 101 -le 100 ']'
+ tag=0
+ case $tag in
+ echo 'The number range is 0-100.'
The number range is 0-100.
[root@localhost shell]# sh -x 1.sh
+ read -p 'Please input a number:' n
Please input a number:59
+ '[' -z 59 ']'
++ echo 59
++ sed 's/[0-9]//g'
+ n1=
+ '[' '!' -z ']'
+ '[' 59 -lt 60 ']'
+ '[' 59 -ge 0 ']'
+ tag=1
+ case $tag in
+ echo 1
1
[root@localhost shell]# sh -x 1.sh
+ read -p 'Please input a number:' n
Please input a number:79
+ '[' -z 79 ']'
++ echo 79
++ sed 's/[0-9]//g'
+ n1=
+ '[' '!' -z ']'
+ '[' 79 -lt 60 ']'
+ '[' 79 -ge 60 ']'
+ '[' 79 -lt 80 ']'
+ tag=2
+ case $tag in
+ echo 2
2
[root@localhost shell]# sh -x 1.sh
+ read -p 'Please input a number:' n
Please input a number:89
+ '[' -z 89 ']'
++ echo 89
++ sed 's/[0-9]//g'
+ n1=
+ '[' '!' -z ']'
+ '[' 89 -lt 60 ']'
+ '[' 89 -ge 60 ']'
+ '[' 89 -lt 80 ']'
+ '[' 89 -ge 80 ']'
+ '[' 89 -lt 90 ']'
+ tag=3
+ case $tag in
+ echo 3
3
[root@localhost shell]# sh -x 1.sh
+ read -p 'Please input a number:' n
Please input a number:a
+ '[' -z a ']'
++ sed 's/[0-9]//g'
++ echo a
+ n1=a
+ '[' '!' -z a ']'
+ echo 'Please input a number.'
Please input a number.
+ exit 1

#!/bin/bash
read -p "Please input a number:" n
if [ -z $n ]
thenecho "Please input a number."exit 1
fi
n1=`echo $n|sed 's/[0-9]//g'`
if [ ! -z $n1 ]
thenecho "Please input a number."exit 1
#elif [ $n -lt 0] || [ $n -gt 100 ]
#then
#    echo "The number range is 0-100."
#    exit 1
fi
if [ $n -lt 60 ] && [ $n -ge 0 ]
thentag=1
elif [ $n -ge 60 ] && [ $n -lt 80 ]
thentag=2
elif [ $n -ge 80 ] && [ $n -lt 90 ]
thentag=3
elif [ $n -ge 90 ] && [ $n -le 100 ]
thentag=4
elsetag=0
fi
case $tag in1)echo "1";;2)echo "2";;3|4)echo "3";;*)echo "The number range is 0-100.";;
esac

这里的if [ ! -z $n1 ]可以用if [ -n "$n1" ]代替

修改于 180208