Iv. Shell Programming Exercises (1-20)

1. Write a script

The script can accept more than one file path as a parameter;

Displays the number of rows held by each file;

Shows how many files have been executed for the number of rows this time.

#!/bin/bashfor file in $*; Do lines= ' wc-l $file | Cut-d '-f1 ' echo ' $file has $lines lines. " Doneecho "$# files." Running results: [[email protected] test]# sh 1.sh/etc/inittab/etc/inittab has lines.1 files.

2. Calculates the sum of the sum and odd numbers of all even numbers within 100, respectively

#!/bin/basheve=0odd=0for ((i=1;i<=100;i++));d o if ' let i%2 ', then let odd=odd+i else let Eve=eve+i fidoneecho " Odd and $odd, even and $eve "Run results: [[email protected] test]# sh 2.sh odd and 2500, even and 2550

3. Calculate the sum of the IDs of all users on the current system

#!/bin/bashdeclare-i idsum=0for i in ' cut-d:-f3/etc//passwd ';d o #由于51cto关键字限制, remove a '/' Let Idsum=idsum+idoneecho $i DSum operation Result: [[email protected] test]# sh 3.sh 68489

4, new 10 user tuser401-tuser410, and beg their ID of the sum

#!/bin/bashdeclare-i idsum=0for i in {401..410};d o useradd tuser$i userid= ' id-u tuser$i ' let IDSUM=IDSUM+USERIDDONEEC Ho "id sum: $idsum" Run result: [[email protected] test]# sh 4.sh ID sum:5045[[email protected] test]# tail/etc//passwd #由于 51cto keyword limit, remove a '/' tuser401:x:500:500::/home/tuser401:/bin/bashtuser402:x:501:501::/home/tuser402:/bin/ bashtuser403:x:502:502::/home/tuser403:/bin/bashtuser404:x:503:503::/home/tuser404:/bin/bashtuser405:x:504:504 ::/home/tuser405:/bin/bashtuser406:x:505:505::/home/tuser406:/bin/bashtuser407:x:506:506::/home/tuser407:/bin/ bashtuser408:x:507:507::/home/tuser408:/bin/bashtuser409:x:508:508::/home/tuser409:/bin/bashtuser410:x:509:509 ::/home/tuser410:/bin/bash

5. Write a script

Create user tuser501-tuser510;

Create directory/tmp/dir-current date time;

In/tmp/dir-current datetime, create 10 empty files in the directory file101-file110

Change the owner of the file101 to tuser501, and so on, and always change the owner of the file110 to tuser510.

#!/bin/bashmkdir -p /tmp/dir/' date +%y-%m-%d ' cd /tmp/dir/' date +%Y-%m-%d ' for i  in {01..10};d O  useradd tuser5$i  mkdir file1$i  chown  tuser5$i file1$idone Running Results:[[email protected] test]# sh 5.sh [[email  protected] test]# tail /etc//passwd        #由于51cto关键字限制, remove a '/' tuser501:x:510:510::/home/tuser501:/bin/bashtuser502:x:511:511::/home/tuser502:/bin/bashtuser503:x:512:512: :/home/tuser503:/bin/bashtuser504:x:513:513::/home/tuser504:/bin/bashtuser505:x:514:514::/home/tuser505:/bin/ bashtuser506:x:515:515::/home/tuser506:/bin/bashtuser507:x:516:516::/home/tuser507:/bin/bashtuser508:x:517:517 ::/home/tuser508:/bin/bashtuser509:x:518:518::/home/tuser509:/bin/bashtuser510:x:519:519::/home/tuser510:/bin/ bash [[email protected] test]# ls -l /tmp/dir/2017-07-03/Total Dosage  40drwxr-xr-x  2 tuser501&Nbsp;root 4096 7 Month    3 14:40 file101drwxr-xr-x 2 tuser502  Root 4096 7 Month    3 14:40 file102drwxr-xr-x 2 tuser503 root  4096 7 Month    3 14:40 file103drwxr-xr-x 2 tuser504 root  4096 7 Month    3 14:40 file104drwxr-xr-x 2 tuser505 root 4096  7 Month    3 14:40 file105drwxr-xr-x 2 tuser506 root 4096 7 Month    3 14:40 file106drwxr-xr-x 2 tuser507 root 4096 7 month     3 14:40 file107drwxr-xr-x 2 tuser508 root 4096 7 Month     3 14:40 file108drwxr-xr-x 2 tuser509 root 4096 7 Month    3  14:40 file109drwxr-xr-x 2 tuser510 root 4096 7 Month    3  14:40 file110

6, separate statistics/etc/rc.d/rc.sysinit,/etc/rc.d/init.d/functions, and/etc/inittab files with # The number of rows and blank lines in the beginning of the row

#!/bin/bashfor file in /etc/rc.d/rc.sysinit /etc/ rc.d/init.d/functions /etc/inittab;do  echo  "The lines contain # in   $file  is  ' grep -e  ' ^#   $file  | wc -l '.   echo  "the space lines in  $file  is  ' grep -e " ^[[:space :]]*$ "  $file  |wc -l '." Done run Result: [[[Email protected] test]# sh 6.sh the lines contain # in  /etc/rc.d/rc.sysinit is 44.the space lines in /etc/rc.d/rc.sysinit is  103.The lines contain # in /etc/rc.d/init.d/functions is 43.The  space lines in /etc/rc.d/init.d/functions is 106.the lines contain #  in /etc/inittab is 25.the space lines in /etc/inittab is 0. 
 

7. Displays the user name, UID, and the UID of all the default shell-bash users on the current system

#!/bin/bashgrep "/bin/bash$"/etc//passwd | cut-d:-f1,3 #由于51cto关键字限制, remove a '/' declare-i sum=0for userID in ' grep '/bin/bash$ '/etc//passwd | cut-d:-f3 ';d o #由于51cto关键字限制, remove a '/' Let Sum=sum+useriddoneecho "$sum" Run Results: [[email protected] test]# sh 7.sh root:00

8. Display the user name of the user with additional groups on the current system, and how many such users are in total

[[email protected] test]# egrep ' [^:]$ '/etc/group | Cut-d:-f4 | Sort-u | Egrep-o ' [[: alnum:]]* ' | Sort-u

9, accept a parameter, this parameter is the user name, if this user exists, then display its ID number

#!/bin/bashread-p "Please enter user name:" Usernameif ID $username &>/dev/null, then echo "$username id ' grep ' ^\< $username \ > "/ETC//PASSWD | cut-d:-f3 ' "Else #由于51cto关键字限制, remove a '/' echo ' Without this user ' fi run result: [[email protected] test]# sh 9.sh Please enter user name: Mysqlmysql ID 496[[email protected] test]# sh 9.sh Please enter user name: 123 No this user

10, through the command line to pass two integer parameters to the script, the script can return its large person

#!/bin/bashread-p "Please enter two integers:" A1 a2if [$a 1-gt $a 2];then echo $a 1else echo $a 2fi run result: [[email protected] test]# sh 10.s h Please enter two integers: one 1616[[email protected] test]# sh 10.sh Please enter two integers: 78 1678

11, the command line to pass any number of integers to the script, the script can return its large person

#!/bin/bashdeclare-i num=0for i in [e-mail protected];d o if [$i-gt $num];then let num=i fidoneecho "maximum number: $num" Run Result: [ [Email protected] test]# sh 11.sh 7978 991 31 3321 32 Maximum: 7978[[email protected] test]# sh 11.sh 78 991 31 3321 32 Maximum number: 3 321

12, given a file path through the command line, and then judge: if there is a blank line in this file, the total number of blank lines is displayed, otherwise, no blank lines are displayed

#!/bin/bashif grep "^[[:space:]]*$" $ &>/dev/null; then echo "$ Have $ (grep" ^[[:space:]]*$ "$ | wc-l) Blank lines. " else echo "No blank lines." Fi operation Result: [[email protected] test]# sh 12.sh/etc//passwd #由于51cto关键字限制, remove a '/' No blank lines. [Email protected] test]# sh 12.sh/etc/inittab No blank lines. [Email protected] test]# SH 12.sh/etc/rc.sysinit/etc/rc.sysinit has 103 blank lines.

13. Pass a parameter to the script:

If the argument is quit, the display says you want to exit;

If the parameter is yes, the display says you want to continue;

Any other parameter, it is said to be unrecognized.

#!/bin/bashcase $ inquit| Q) echo "Exit program";; yes| Y) echo "continue";; *) echo "unrecognized";; Esac Run Result: [[email protected] test]# sh 13.sh unrecognized [[email protected] test]# sh 13.sh quit quit program [[email protected] test]# SH 1 3.sh Yes continue

14. Pass a user name to the script:

If this user's ID number is 0, then the display says this is the administrator;

If this user's ID number is greater than or equal to 500, the display says this is a normal user

Otherwise, it is said that this is the system user;

#!/bin/bashif id $1 &>/dev/null ;then  userid= '  grep  ' ^\<$1\ > " /etc//passwd | cut -d: -f3 "    #由于51cto关键字限制, remove a '/'    if [  $userid  -eq 0 ];then    echo  "$1  is the administrator."   elif [  $userid  -ge 500 ];then    echo  "$1  is a normal user. "   else    echo  "$1  is a system user."   fielse  echo  "No this user." Fi Run result:[[email protected] test]# sh 14.sh mysql mysql  is the system user. [[Email protected] test]# [[email protected] test]# sh 14.sh mysql  mysql  is a system user. [[email protected] test]# sh 14.sh rootroot  is an administrator. [[email protected] test]# sh 14.sh nfsnobodynfsnobody  is an ordinary user. [[email protected] test]# sh 14.sh Nfsnobo "No this user." 

15, given a user, if its shell is/bin/bash and its ID number is greater than or equal to 500, then it is a logon to a normal user; otherwise, it will be displayed as a non-logged-on user or administrator.

#!/bin/bashif id $1 &> /dev/null ;then  userid= ' grep  ' ^\<$1\ > " /etc//passwd | cut -d: -f3 '     #由于51cto关键字限制, remove a '/'    Usershell= ' grep  ' ^\<$1\> '  /etc//passwd | cut -d: -f7 ' #由于51cto关键字限制, remove a '/'   if [  $userid  -ge 500 ] && [  "$usershell" = = "/bin/ Bash " ];then    echo " $1  is available for regular users "  else     echo  "$1  is a non-login user or administrator"   fielse  echo  "no this user." Fi Run result:[[email protected] test]# sh 15.sh rootroot  is a non-login user or Administrator [[email  protected] test]# sh 15.sh mysqlmysql  is a non-login user or Administrator [[email protected] test]#  sh 15.sh nfsnobodynfsnobody  is available to login to ordinary users [[email protected] test]# sh 15. Sh nfsnobo no such user.

16, write a script, if a user does not exist, add

#!/bin/bashif ID $ &>/dev/null; then echo "$ already exists." Else useradd echo "Add user $." Fi run Result: [[email protected] test]# sh 16.sh mysqlmysql already exists. [[Email protected] test]# sh 16.sh mylinux Add user mylinux. [[email protected] test]# tail-1/etc//passwd #由于51cto关键字限制, remove a '/' Mylinux:x:500:500::/home/mylinux:/bin/bash

17. Add 10 Users: tuser501-tuser510; If the user does not exist, it is added; if present, the user is displayed; Shows how many users have been added altogether.

#!/bin/bashdeclare -i num=0for i in {501..510}; Do  if id tuser$i &> /dev/null ;then    echo   "tuser$i  already exists"   else    useradd tuser$i         echo  "Add user  tuser$i"         let  num++  fidoneecho  "Add $num  users." Run results:[[email protected] test]# sh 17.sh   Add user  tuser501 Add users   tuser502 Add user  tuser503 Add user  tuser504 Add user  tuser505 Add user  tuser506 Add user  tuser507 Add users   tuser508 Add a user  tuser509 add a user  tuser510 add 10  users. [[email protected] test]# sh 17.sh tuser501  already exists tuser502  already exists tuser503  Existing tuser504  already exists tuser505  already exists tuser506  already exists tuser507  already exists tuser508  already exists tuser509  An existing tuser510  already exists to add 0  users. 

18, add 10 Users: tuser601-tuser610, add if the user does not exist, add success with green display, and if present, show this user in red ; Shows how many users have been added altogether.

#!/bin/bash#declare -i count=0for i in {601..610}; do  if id  tuser$i &> /dev/null; then    echo -e  "\033[31mtuser $i \033[0m exists. "   else        useradd tuser$i         echo -e  "add user \033[32mtuser$i\033[0m successfully."         let count++  fidoneecho  "Total add   $count  users. " Run result:[[email protected] test]# sh 18.sh add user tuser601  Successfully.add user tuser602 successfully.add user tuser603 successfully.add  user tuser604 successfully.add user tuser605 successfully.add user  Tuser606 successfully.add user tuser607 successfully.add user tuser608&nbsP;successfully.add user tuser609 successfully.add user tuser610 successfully. Total add 10 users. [[email protected] test]# sh 18.sh tuser601 exists.tuser602 exists.tuser603  exists.tuser604 exists.tuser605 exists.tuser606 exists.tuser607 exists.tuser608  exists.tuser609 exists.tuser610 exists. Total add 0 users.

19. Pass the user name to the script

Determine if this user's shell is/bin/bash, and if so, show this user as Basher

Otherwise, this user is displayed as a non-basher

#!/bin/bash#usershell= ' grep ' ^$1\> '/etc//passwd | cut-d:-f7 ' #由于51cto关键字限制, remove a '/' if [' $userShell ' = = '/bin/bash ']; Then echo "basher" else echo "not basher" fi run result: [[email protected] test]# sh 19.sh mysqlnot basher[[email protected] Test ]# SH 19.sh mylinuxbasher

20. Given a file path

Determine if the file exists, does not exist, the file is not present, and the script is finished directly;

If the file is a normal file, it is displayed as "regular";

If the file is a directory, it is displayed as "directory";

If the file is a linked file, it is displayed as "symbolic file";

Otherwise, it is displayed as "unknown type."

#!/bin/bashif [ ! -e $1 ];then  echo   "FILE NOT EXIT ."   exit 5fiif [ -L $1 ];then  echo  "Symbolic file." elif [ -d $1 ];then  echo  "directory." elif [-f $1 ];then  echo  "Regular file." else  echo  "Unknown type." Fi run Result: [[Email protected] test]# sh 20.sh /etc/directory. [[email protected] test]# sh 20.sh /etc/rc.d/rc1.d/k92iptables       symbolic file. [[email protected] test]# sh 20.sh 12312file not exit . 

This article is from the "Wind and Drift" blog, please be sure to keep this source http://yinsuifeng.blog.51cto.com/10173491/1944179

Iv. Shell Programming Exercises (1-20)