shell脚本，通过传参求斐波那契数列如（0,1,1,2,3,5,8,13..........）

[root@localhost wyb]# cat fibo.sh 
#!/bin/bash

#斐波那契数列 0,1,1,2,3,5,8,13

echo 0 > file
echo 1 >> file

count=$1

for i in `seq $count`
do
first=$(tail -2 file |head -1)
two=$(tail -1 file)
echo $((first+two)) >> file
done
cat file
[root@localhost wyb]# bash fibo.sh 10
0
1
1
2
3
5
8
13
21
34
55
89
[root@localhost wyb]# bash fibo.sh 7
0
1
1
2
3
5
8
13
21
[root@localhost wyb]# 

第二种方法，通过间接赋值来来传。用到read -p

[root@localhost wyb]# cat 2fibo.sh 
#!/bin/bash

#斐波那契数列 0,1,1,2,3,5,8,13

echo 0 > file
echo 1 >> file

#count=$1
read -p "Please Input a  number:" count
for i in `seq $count`
do
first=$(tail -2 file |head -1)
two=$(tail -1 file)
echo $((first+two)) >> file
done
cat file
[root@localhost wyb]# bash 2fibo.sh 
Please Input a  number:4
0
1
1
2
3
5
[root@localhost wyb]# bash 2fibo.sh 
Please Input a  number:6
0
1
1
2
3
5
8
13
[root@localhost wyb]# bash 2fibo.sh 
Please Input a  number:20
0
1
1
2
3
5
8
13
21
34
55
89
144
233
377
610
987
1597
2584
4181
6765
10946
[root@localhost wyb]#