Simple shell programming of Linux

Sharing a few shell programming, easy to Review of linux

 

 

 

1. The user determines whether the input number palindrome

 1 #!/bin/bash
 2 read in
 3 res=`echo $in|rev`
 4 if [ $res -eq $in ]
 5 then
 6         echo "$in is a huiwenshu!" 7 elif [$ in $ res -what ]
 8 then 9 echo "$in not is a huiwenshu" 10 fi

 2. Calculate the factorial of a number of user input

 1 #!/bin/bash
 2 sum=1
 3 i=1
 4 read n
 5 while [ $i -le $n ]
 6 do
 7 sum=$[$sum*$i]
 8 i=$[$i+1]
 9 done
10 echo "sum=$sum"

3. The user input is determined whether the number is a prime number

 1 #!/bin/bash
 2 read num
 3 declare -i count=0
 4 for n in `seq 1 $num`
 5 do
 6         if [ $((num%n)) -eq 0 ]
 7         then
 8         count=$[$count+1]
 9         fi
10 done
11 if [ $count -eq 2 ]
12 then
13         echo "$num is a prime num"
14 else echo "$num not is a prime num"
15 fi

Item 4. The first n Fei not calculate the number of columns that the wedge and

 1 #!/bin/bash
 2 read num
 3 a=1           
 4 b=1
 5 c=0 
 6 sum=0
 7 for((i=0;i<num;i++))
 8 do
 9         echo "$a"
10         let sum+=a
11         let c=a+b 
12         let a=b 
13         let b=c 
14 done
15 echo "sum=$sum"