i need help

whc

i had this question but i dontknow how to solve it,

Write a shell script which receives any year from the keyboard and determines whether the year is leap year or not

i am a new user in unix
hopefully someone will know how to do it
thanks

laoxia

牛一点的

1. #!/bin/ksh
   
2. 
   
3. function cal_year {
   
4. echo "please enter the year: "
   
5. read year
   
6. leap_value=` expr $year % 4 `
   
7. 
   
8. if [ $leap_value -eq 0 ]
   
9.   then
   
10.     echo "$year is leap year"
    
11.   else
    
12.     echo "$year is not leap year"
    
13. fi
    
14. 
    
15. echo "Do you have some other year to enter? (please input yes or no) "
    
16. read input
    
17. 
    
18. case $input in
    
19. y|Y|yes|Yes|YES) cal_year ;;
    
20. n|N|no|No|NO)    exit ;;
    
21. *)               echo "pleas enter yes or no!" ;;
    
22. esac
    
23. }
    
24. 
    
25. cal_year

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袖珍型的

1. 
   
2. #!/bin/ksh
   
3. echo "please enter the year: "
   
4. read year
   
5. leap_value=` expr $year % 4 `
   
6. 
   
7. if [ $leap_value -eq 0 ]
   
8.   then
   
9.     echo "$year is leap year"
   
10.   else
    
11.     echo "$year is not leap year"
    
12. fi

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laoxia

弟兄们，俺是不是有点笨啦？

whc

thanks for your help men

红袖添香

...

it's quite easy. you may write a subroutine that verifies:

1)  if modulo 4 gives 0, it's a leap year
2)  but if modulo 100 also gives 0, then it isn't
3)  however, if modelo 400 gives 0 again, then it's a leap year again.

but i'd like not do so complicated. Much easier will be:

1. 
   
2. #!/bin/sh
   
3. 
   
4. test -z $1 && echo "Usage: $0 YYYY" && exit 1
   
5. YYYY=$1
   
6. STR=`cal 02 $YYYY`
   
7. LASTDAY=`echo $STR | awk '{print $NF}'`
   
8. if  [ x$LASTDAY = x28 ]; then
   
9.         echo "No, year $YYYY is NOT a leap year."
   
10. elif  [ x$LASTDAY = x29 ]; then
    
11.         echo "Yes, year $YYYY is a leap year."
    
12. else
    
13.         echo "eh... something wrong with year $YYYY..."
    
14.         exit 2
    
15. fi
    

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but if you are a student majored in computer science and it's your assignment, you'd better do it in ordinary way, since your professor will be happy with your algorithm instead of solution.

laoxia

> 2) but if modulo 100 also gives 0, then it isn't


原来能被100整除就不是闰年啦？真就不知也

tiansgx

没学过数学？

laoxia

数学里有这个？

tiansgx

偶记得小学数学就讲过什么是闰年的问题，难道大虾是传说中的神童，不用读小学？

nkliyong

俺也给一个

#usage: command YYYY

aa=`cal 02 $1`
bb=`echo $aa|awk '{print $NF}'`
if [ $bb -eq 29 ];then
echo "$1 is leap year"
fi