如何将这个if脚本改为case脚本

46212635

if语句改为case语句，来简化脚本

1. #!/bin/bash
   
2. # --------------------------------------------
   
3. # 按键产生的字符编码.
   
4. arrowup='\[A'
   
5. arrowdown='\[B'
   
6. arrowrt='\[C'
   
7. arrowleft='\[D'
   
8. # --------------------------------------------
   
9. 
   
10. SUCCESS=0
    
11. OTHER=65
    
12. 
    
13. echo -n "Press a key... "
    
14. read -n3 key # 读3 个字符.
    
15. 
    
16. echo -n "$key" | grep "$arrowup" #检查输入字符是否匹配.
    
17. if [ "$?" -eq $SUCCESS ]
    
18. then
    
19. echo "Up-arrow key pressed."
    
20. exit $SUCCESS
    
21. fi
    
22. 
    
23. echo -n "$key" | grep "$arrowdown"
    
24. if [ "$?" -eq $SUCCESS ]
    
25. then
    
26. echo "Down-arrow key pressed."
    
27. exit $SUCCESS
    
28. fi
    
29. 
    
30. echo -n "$key" | grep "$arrowrt"
    
31. if [ "$?" -eq $SUCCESS ]
    
32. then
    
33. echo "Right-arrow key pressed."
    
34. exit $SUCCESS
    
35. fi
    
36. 
    
37. echo -n "$key" | grep "$arrowleft"
    
38. if [ "$?" -eq $SUCCESS ]
    
39. then
    
40. echo "Left-arrow key pressed."
    
41. exit $SUCCESS
    
42. fi
    
43. 
    
44. echo " Some other key pressed."
    
45. exit $OTHER
    

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yongsheng_2012

1. #!/bin/bash
   
2. arrowup='\[A'
   
3.     arrowdown='\[B'
   
4.     arrowrt='\[C'
   
5.     arrowleft='\[D'
   
6.     # --------------------------------------------
   
7. 
   
8.     SUCCESS=0
   
9.     OTHER=65
   
10. 
    
11.     echo -n "Press a key... "
    
12.     read -n3 key # 读3 个字符.
    
13.     case $key in
    
14.         $arrowup)
    
15.         echo "Up-arrow key pressed."
    
16.         exit $SUCCESS;;
    
17.         $arrowdown)
    
18.         echo "Down-arrow key pressed."
    
19.         exit $SUCCESS;;
    
20.         $arrowrt)
    
21.         echo "Right-arrow key pressed."
    
22.         exit $SUCCESS;;
    
23.         $arrowleft)
    
24.         echo "Left-arrow key pressed."
    
25.         exit $SUCCESS;;
    
26.         *)
    
27.         echo " Some other key pressed."
    
28.         exit $OTHER;;
    
29.       esac
    
30. ~        

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看看是这样不？

46212635

回复 2# yongsheng_2012
这个我也试过，错的，结果都是Some other key pressed.
麻烦你先运行一下


   

46212635

回复 2# yongsheng_2012
key和arrowup，arrowdown，arrowrt，arrowleft不相等


   

yongsheng_2012

[root@yong tmp]# bash 1.sh
Press a key... \[A
Up-arrow key pressed.
[root@yong tmp]# bash 1.sh
Press a key... \[C
Right-arrow key pressed.
[root@yong tmp]#

还要我再说吗

46212635

回复 5# yongsheng_2012
为毛我的上下左右键按出来跟你不一样呢？

[root@shell ~]# bash 1.sh
Press a key... ^[[A Some other key pressed.
[root@shell ~]# bash 1.sh
Press a key... ^[[C Some other key pressed.

   

46212635

回复 5# yongsheng_2012


    还有你上面写的echo -n "Press a key... "，请问你下面的输出是怎么换的行？

linjiecyd

你自己输入有问题 ，^[[跟你说的\[到底哪个对

46212635

回复 8# linjiecyd

麻烦你运行下脚本，在截个图给我看下~我换了系统，换了电脑，敲出来的结果还是一样~

我确保我的输入没问题


   

rdcwayx

好像我已经回答过你的问题了， http://bbs.chinaunix.net/thread-3772720-1-1.html

那个就是用case statement 的

注意: 1、"^[[A"为ctrl+v后按ESC 键 ，和 [ 和 A;
        2、"^[[B"为ctrl+v后按ESC 键 ，和 [ 和 B;
        3. 其他的类似

1. #!/bin/bash
   
2. #检查方向键
   
3. #edited by xxt
   
4. arrowup='^[[A'
   
5. arrowdown='^[[B'
   
6. arrowrt='^[[C'
   
7. arrowleft='^[[D'
   
8. insert='^[[2'
   
9. delete='^[[3'
   
10. 
    
11. echo -n "Press a key... "
    
12. read -n3 key
    
13. 
    
14. echo
    
15. 
    
16. case $key in
    
17.   "$arrowup")
    
18.      echo "Up-arrow key is pressed"
    
19.      ;;
    
20.   "$arrowdown")
    
21.      echo "Down-arrow key is pressed"
    
22.      ;;
    
23.   "$arrowrt")
    
24.      echo "Right-arrow key is pressed"
    
25.      ;;
    
26.   "$arrowleft")
    
27.      echo "Left-arrow key is pressed"
    
28.      ;;
    
29.   "$insert")
    
30.      echo "Insert key is pressed"
    
31.      ;;
    
32.   "$delete")
    
33.      echo "Delete key is pressed"
    
34.      ;;
    
35.   *)
    
36.      echo "The args which you input is wrong"
    
37.      ;;
    
38. esac
    
39. exit

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