Shell简单实例

实例 1-2-6

if [ -z $1 ]||[ -z $2 ]

then

    echo "please input two numbers"

    exit

else if [ $1 -gt $2 ] ; then

    echo "Param1 > Param2"

else if [ $1 -lt $2 ] ; then

        echo "Param1 < Param2"

else

    echo "Param1 == Param2"

    fi

fi

fi

结果

[root@localhost code_linux]# ./1-2-6

please input two numbers

[root@localhost code_linux]# ./1-2-6 3 3

Param1 == Param2

[root@localhost code_linux]# ./1-2-6 3 4

Param1 < Param2

[root@localhost code_linux]# ./1-2-6 3 1

Param1 > Param2

实例 1-2-7

#!/bin/bash

counter=0

for files in *

do

    if [ -f "$files" ] ; then

        counter=`expr $counter + 1`     #等价于counter=$( ($counter + 1)) 

    fi

done

echo "There are $counter files in `pwd`"

结果

[root@localhost code_linux]# ls

1-2-6  1-2-7

[root@localhost code_linux]# ./1-2-7

There are 2 files in /home/lidong/code_linux

例1-2-8

#!/bin/bash

echo -n "Please enter number:"

read n

sd=0

rev=""

on=$n

echo "You put number is $n"

while [ $n -gt 0 ]

do

    sd=$(( $n % 10 ))

    n=$(( $n / 10 ))

    rev="$rev$sd"

done

echo "$on in a reverse order $rev"

结果

[root@localhost code_linux]# ./1-2-8

Please enter number:12345

You put number is 12345

12345 in a reverse order 54321