shell 脚本实例 1. 写一个脚本,利用循环计算10 的阶乘 #!/bin/sh factorial=1 for a in `seq 1 10` do factorial=`expr $factorial \* $a` done echo "10! = $factorial" 注:上面有一行,for a in `seq 1 10`,其中seq 1 10 , 即列出现1 到 10 之间所有的数字,这一行也可改为:for a in "1 2 3 4 5 6 7 8 9 10" 2. 写一个脚本,执行后,打印一行提示“Please input a number:",要求用户输入数值,然 后打印出该数值,然后再次要求用户输入数值。直到用户输入 "end"停止。 #!/bin/sh unset var while [ "$var" != "end" ] do echo -n "please input a number: " read var if [ "$var" = "end" ] then break fi echo "var is $var" done 3. 写一个脚本,利用循环和continue 关键字,计算100 以内能被3 整除的数之和 #!/bin/sh sum=0 for a in `seq 1 100` do if [ `expr $a % 3` -ne 0 ] then continue fi echo $a sum=`expr $sum + $a` done echo "sum = $sum" 4.一个函数,利用shift 计算所有参数乘积,假设参数均为整数( 特殊变量$# 表示包含参数的个数) #! /bin/sh result=1 while [ $# -gt 0 ] do result=`expr $result \* $1` shift done echo $result 5.写一个脚本,可以根据参数文件名,以正确的参数调用tar 来解压缩tar.gz 或 tar.bz2文件。 #!/bin/sh case ${1##*.tar.} in bz2) tar jxvf $1 ;; gz) tar zxvf $1 ;; *) echo "wrong file type" esac 6. 写一个脚本以方便用户查询rpm 的相关信息。这个脚本首先提示用户选择查询依据,比如 文件名,包名,全部等。然后提示用户选择查询信息,比如包名,包里所包含的所有文件, 包的信息等。然后询问是否继续查询,是则循环刚才的过 程,否则退出。 #!/bin/sh RPM=/bin/rpm option="-q" while true do echo "what to query?" select var in "All" "file" "package name" do case $var in All) option=$option"a" break ;; file) echo -n "please input file name: " option=$option"f" read argument break ;; package\ name) echo -n "please input package name: " read argument break ;; *) echo "please choose between 1-3" ;; esac done echo "what do you want to know?" select var in "location" "info" "package name" do case $var in location) option=$option"l" break ;; info) option=$option"i" break ;; package\ name) break ;; *) echo "please choose between 1-3" ;; esac done ${RPM} $option $argument echo "continue? [yes/no]" read answer if [ answer = "no" ] then break fi done