shell脚本练习题shell脚本练习题.doc

shell脚本例子集锦（习题总结） 练习一：写一个脚本?????? 1.设定变量FILE的值为/etc/passwd?????? 2.依次向/etc/passwd中的每个用户问好，并且说出对方的ID是什么??????? 形如：（提示：LINE=`wc -l /etc/passwd | cut -d -f1`)???????? Hello,root，your UID is 0.?????? 3.统计一个有多少个用户???? 答案一：#!/bin/bash?????????? file=/etc/passwd?????????? LINES=`wc -l $file | cut -d -f1`?????????? for I in `seq 1 $LINES`;do?????????? userid=`head -$I $file | tail -1 |cut -d: -f3`?????????? username=`head -$I $file | tail -1 |cut -d: -f1`?????????? echo hello $username,your UID is $userid?????????? done?????????? echo there are $LINES users???? 答案二：#!/bin/bash?????????? file=/etc/passwd?????????? let num=0?????????? for I in `cat $file`;do?????????? username=`echo $I | cut -d: -f1`?????????? userid=`echo $I | cut -d: -f3`?????????? echo Hello,$username,your UID is $userid?????????? num=$[$num+1]?????????? done?????????? echo there are $num users练习二：写一个脚本????? 1.切换工作目录至/var????? 2.依次向/var目录中的每个文件或子目录问好，形如：??????? （提示：for FILE in /var/*;或for FILE in `ls /var`;)??????? Hello,log????? 3.统计/var目录下共有多个文件，并显示出来? 答案：#!/bin/bash???????? cd /var???????? let num=0???????? for I in `ls /var/*`;do???????? echo hello $I???????? num=$[$num+1]???????? done???????? echo the number of files is $num练习三：写一个脚本????? 1.设定变量file的值为/etc/passwd????? 2.使用循环读取文件/etc/passwd的第2,4,6,10,13,15行，并显示其内容????? 3.把这些行保存至/tmp/mypasswd文件中? 答案：#!/bin/bash?????? file=/etc/passwd?????? for I in 2 4 6 10 13 15;do?????? exec 3/tmp/mypasswd?????? line=`head -$I $file | tail -1`?????? echo $line?????? echo $line 3?????? exec 3-?????? done 练习四：写一个脚本 ???????传递两个整数给脚本，让脚本分别计算并显示这两个整数的和，差，积，商????????答案如下：vim test.sh?????????????????? #!/bin/bash??????????????????? echo first number $1? （表示输出第一个数） ????????????????????echo second number $2 （表示输出第二个数）????????????????????echo $(($1+$2))????? （输出两数之和）????????????????????echo $[$1-$2]???????? （输出两数之差）??????????????????? echo $[$1*$2]???????? （输出两数之积） ????????????????????echo $[$1/$2]???????? （输出两数之商）???