Linux Interview Questions For software testers


Posted in 面试题 onJune 02, 2012
Software testing – Questions and Answers – Linix / Unix

1. Q. How do you list files in a directory?
A. ls – list directory contents
ls ?l (-l use a long listing format)

2. Q. How do you list all files in a directory, including the hidden files?
A. ls -a (-a, do not hide entries starting with .)

3. Q. How do you find out all processes that are currently running?
A. ps -f (-f does full-format listing.)

4. Q. How do you find out the processes that are currently running or a particular user?
A. ps -au Myname (-u by effective user ID (supports names)) (a – all users)

5. Q. How do you kill a process?
A. kill -9 8 (process_id 8) or kill -9 %7 (job number 7)
kill -9 -1 (Kill all processes you can kill.)
killall – kill processes by name most (useful – killall java)

6. Q. What would you use to view contents of the file?
A. less filename
cat filename
pg filename
pr filename
more filename
most useful is command: tail file_name – you can see the end of the log file.

7. Q. What would you use to edit contents of the file?
A. vi screen editor or jedit, nedit or ex line editor

8. Q. What would you use to view contents of a large error log file?
A. tail -10 file_name ( last 10 rows)

9. Q. How do you log in to a remote Unix box?
A. Using telnet server_name or ssh -l ( ssh – OpenSSH SSH client (remote login program))

10.Q. How do you get help on a UNIX terminal?
A. man command_name
info command_name (more information)

11.Q. How do you list contents of a directory including all of its
subdirectories, providing full details and sorted by modification time?
A. ls -lac
-a all entries
-c by time

12.Q. How do you create a symbolic link to a file (give some reasons of doing so)?
A. ln /../file1 Link_name
Links create pointers to the actual files, without duplicating the contents of
the files. That is, a link is a way of providing another name to the same file.
There are two types of links to a file:Hard link, Symbolic (or soft) link;

13.Q. What is a filesystem?
A. Sum of all directories called file system.
A file system is the primary means of file storage in UNIX.
File systems are made of inodes and superblocks.

14.Q. How do you get its usage (a filesystem)?
A. By storing and manipulate files.

15.Q. How do you check the sizes of all users? home directories (one command)?
A. du -s
df

The du command summarizes disk usage by directory. It recurses through all subdirectories and shows disk usage by each subdirectory with a final total at the end.

Q. in current directory
A. ls -ps (p- directory; s – size)

16.Q. How do you check for processes started by user ‘pat’?

A. ps -fu pat (-f -full_format u -user_name )

17.Q. How do you start a job on background?

A. bg %4 (job 4)

18 Q. What utility would you use to replace a string ’2001′ for ’2002′ in a text file?

A. Grep, Kde( works on Linux and Unix)

19. Q. What utility would you use to cut off the first column in a text file?
A. awk, kde

20. Q. How to copy file into directory?
A. cp /tmp/file_name . (dot mean in the current directory)

21. Q. How to remove directory with files?
A. rm -rf directory_name

22. Q. What is the difference between internal and external commands?
A. Internal commands are stored in the; same level as the operating system while external
commands are stored on the hard disk among the other utility programs.

23. Q. List the three main parts of an operating system command:
A. The three main parts are the command, options and arguments.

24 Q. What is the difference between an argument and an option (or switch)?
A. An argument is what the command should act on: it could be a filename,
directory or name. An option is specified when you want to request additional
information over and above the basic information each command supplies.

25. Q. What is the purpose of online help?
A. Online help provides information on each operating system command, the
syntax, the options, the arguments with descriptive information.
26. Q. Name two forms of security.
A. Two forms of security are Passwords and File Security with permissions specified.

27. Q. What command do you type to find help about the command who?
A. $ man who

28. Q. What is the difference between home directory and working directory?
A. Home directory is the directory you begin at when you log into the
system. Working directory can be anywhere on the system and it is where you are currently
working.

29. Q. Which directory is closer to the top of the file system tree, parent directory or current directory?
A. The parent directory is above the current directory, so it is closer to
the root or top of the
file system.

30. Q. Given the following pathname:
$ /business/acctg/payable/supplier/april
a) If you were in the directory called acctg, what would be the relative
pathname name for the file called april?
b) What would be the absolute pathname for april?
A.
a) $ payable/supplier/april
b) $ /business/acctg/payable/supplier/april

31. Q. Suppose your directory had the following files:
help. 1 help.2 help.3 help.4 help.O1 help.O2
aid.O1 aid.O2 aid.O3 back. 1 back.2 back.3
a) What is the command to list all files ending in 2?
b) What is the command to list all files starting in aid?
c) What is the command to list all “help” files with one character extension?
A.
a) ls *2
b) ls aid.*
c) ls help.?

32. Q. What are two subtle differences in using the more and the pg commands?
A. With the more command you display another screenful by pressing
the spacebar, with pg you press the return key.
The more command returns you automatically to the UNIX
shell when completed, while pg waits until you press return.

33. Q. When is it better to use the more command rather than cat command?
A. It is sometimes better to use the more command when you are viewing
a file that will display over one screen.

34. Q. What are two functions the move mv command can carry out?
A. The mv command moves files and can also be used to rename a file or directory.

35. Q. Name two methods you could use to rename a file.
A. Two methods that could be used:
a. use the mv command
b. copy the file and give it a new name and then remove the original file if no longer needed.

36. The soccer league consists of boy and girl teams. The boy file names begin
with B, the girl teams begin with G. All of these files are in one directory
called “soccer”, which is your current directory:
Bteam.abc Bteam.OOl Bteam.OO2 Bteam.OO4
Gteam.win Gteam.OOl Gteam.OO2 Gteam.OO3
Write the commands to do the following:
a) rename the file Bteam.abc to Bteam.OO3.
b) erase the file Gteam. win after you have viewed the contents of the file
c) make a directory for the boy team files called “boys”, and one for the girl team files
called” girls”
d) move all the boy teams into the “boys” directory
e) move all the girl teams into the “girls” directory
f) make a new file called Gteam.OO4 that is identical to Gteam.OOl
g) make a new file called Gteam.OO5 that is identical to Bteam.OO2
A.
a) mv Bteam.abc Bteam.OO3.
b) cat Gteam.win -or- more Gteam.win
rm Gteam. win
c) mkdir boys
mkdir girls
d) mv Bteam* boys
e) mv Gteam* girls
f) cd girls
cp Gteam.OO1 Gteam.OO4
g) There are several ways to do this. Remember that we are currently in the directory
/soccer/girls.
cp ../boys/Bteam.OO2 Gteam.OO5
or
cd ../boys
cp Bteam.OO2 ../girls/Gteam.OO5

37. Q. Draw a picture of the final directory structure for the “soccer”
directory, showing all the files and directories.

38. Q. What metacharacter is used to do the following:
1.1 Move up one level higher in the directory tree structure
1.2 Specify all the files ending in .txt
1.3 Specify one character
1.4 Redirect input from a file
1.5 Redirect the output and append it to a file
A.
1. 1.1 double-dot or ..
1.2 asterisk or *
1.3 question or ?
1.4 double greater than sign: >>
1.5 the less than sign or
39. Q. List all the files beginning with A
A. To list all the files beginning with A command: ls A*

40. Q. Which of the quoting or escape characters allows the dollar sign ($) to retain its special meaning?
A. The double quote (“) allows the dollar sign ($) to retain its special meaning.
Both the backslash (\) and single quote (‘) would remove the special meaning of the dollar sign.

41. Q. What is a faster way to do the same command?
mv fileO.txt newdir
mv filel.txt newdir
mv file2.txt newdir
mv file3.txt newdir
A. A shortcut method would be: mv file?.txt newdir

42. Q. List two ways to create a new file:
A.
a. Copy a file to make a new file.
b. Use the output operator e.g. ls -l > newfile.txt

43. Q. What is the difference between > and >> operators?
A. The operator > either overwrites the existing file (WITHOUT WARNING) or creates a new file.
The operator >> either adds the new contents to the end of an existing file or creates a new file.

44. Write the command to do the following:
44.1 Redirect the output from the directory listing to a printer.
44.2 Add the file efg.txt to the end of the file abc.txt.
44.3 The file testdata feeds information into the file called program
44.4 Observe the contents of the file called xyz.txt using MORE.
44.5 Observe a directory listing that is four screens long.
A.
44.1 ls > lpr
44.2 cat efg.txt >> abc.txt
44.3 program 44.4 more 44.5 ls > dirsave | more

45. Q. How do you estimate file space usage
A. Use du command (Summarize disk usage of each FILE, recursively for
directories.) Good to use arguments du -hs
(-h, –human-readable print sizes in human readable format (e.g., 1K 234M 2G)
(-s, –summarize display only a total for each argument)

46. Q. How can you see all mounted drives?
A. mount -l

47. Q. How can you find a path to the file in the system?
A. locate file_name (locate – list files in databases that match a pattern)

48. Q. What Linux HotKeys do you know?
A. Ctrl-Alt-F1 Exit to command prompt
Ctrl-Alt-F7 or F8 Takes you back to KDE desktop from command prompt
Crtl-Alt-Backspace Restart XWindows
Ctrl-Alt-D Show desktop

49. Q. What can you tell about the tar Command?
A. The tar program is an immensely useful archiving utility. It can combine
an entire directory tree into one large file suitable for transferring or
compression.

50. Q. What types of files you know?
A. Files come in eight flavors:
Normal files
Directories
Hard links
Symbolic links
Sockets
Named pipes
Character devices
Block devices

51. Q. How to copy files from on PC to another on the same network
A. Use the following command:scp yur_file you_login@your_IP
example: copy .conf file from your PC to alex computer-
scp /etc/X11/xorg.conf alex@10.0.10.169:

52. Q. Please describe information below:

-rw-rw-r– 1 dotpc dotpc 102 Jul 18 2003 file.buf
drwxr-xr-x 9 dotpc dotpc 4096 Oct 21 09:34 bin
lrwxrwxrwx 1 dotpc dotpc 20 Mar 21 15:00 client -> client-2.9.5
drwxrwxr-x 11 dotpc dotpc 4096 Sep 2 2005 client-2.8.9
drwxrwxr-x 7 dotpc dotpc 4096 Dec 14 12:13 data
drwxr-xr-x 12 dotpc dotpc 4096 Oct 21 09:41 docs
drwxr-xr-x 5 dotpc dotpc 4096 Dec 7 14:22 etc
drwxr-xr-x 11 dotpc dotpc 4096 Mar 21 15:54 client-2.9.5
-rw-r–r– 1 dotpc dotpc 644836 Mar 22 09:53 client-2.9.5.tar.gz

A. This is a result of command $ls -l
we have two files, 6 directories and one link to client-2.9.5 directory.
There is number of files in every directory, size and data of last change.

53. Q. If you would like to run two commands in sequence what operators you can use?

A. ; or && the difference is:
if you separate commands with ; second command will be run automatically.
if you separate commands with && second command will be run only in the case
the first was run successfully.

54. Q. How you will uncompress the file?
A. Use tar command (The GNU version of the tar archiving utility):
tar -zxvf file_name.tar.gz

55. Q.How do you execute a program or script, my_script in your current directoty?
A. ./my_script

56. Q.How to find current time configuration in the file my_new.cfg
A. grep time my_new.cfg
Grep searches the named input files (or standard input if
no files are named, or the file name – is given) for lines
containing a match to the given pattern.

Q. What does grep() stand for?
A. General Regular Expression Parser.

57. Q. What does the top command display?
A. Top provides an ongoing look at processor activity in real
time. It displays a listing of the most CPU-intensive
tasks on the system, and can provide an interactive inter-
face for manipulating processes. (q is to quit)

58. Q. How can you find configuration on linux?
A. by using /sin/ifconfig
If no arguments are given, ifconfig displays the status of the cur-
rently active interfaces. If a single interface argument is given, it displays the status of the given interface only; if a single -a argu-
ment is given, it displays the status of all interfaces, even those
that are down. Otherwise, it configures an interface.

59. Q. How to find difference in two configuration files on the same server?
A. Use diff command that is compare files line by line
diff -u /usr/home/my_project1/etc/ABC.conf /usr/home/my_project2/etc/ABC.conf

60. Q. What is the best way to see the end of a logfile.log file?
A. Use tail command – output the last part of files
tail -n file_name ( the last N lines, instead of the last 10 as default)

61. Q. Please write a loop for removing all files in the current directory that contains a word ‘log’
A. for i in *log*; do rm $i; done

62. Question: How to switch to a previously used directory?
Answer: cd -

Tags in this post...

面试题 相关文章推荐
PHP笔试题
Feb 22 面试题
垃圾回收的优点和原理。并考虑2种回收机制
Oct 16 面试题
求网格中的黑点分布
Nov 06 面试题
C++:memset ,memcpy和strcpy的根本区别
Apr 27 面试题
如何为DataGridView添加一个定制的Column Type
Jan 21 面试题
extern是什么意思
Mar 10 面试题
C#中的验证控件有几种
Mar 08 面试题
为什么要用EJB
Apr 17 面试题
万户网络JAVA程序员岗位招聘笔试试卷
Jan 08 面试题
Servlet的实例是在生命周期什么时候创建的?配置servlet最重要的是什么?
May 30 面试题
Ruby如何定义一个类
Oct 08 面试题
如何将一个描述日期或日期/时间的字符串转换为一个Date对象
Oct 13 面试题
Linux的文件类型
Mar 07 #面试题
什么是Linux虚拟文件系统VFS
Jan 31 #面试题
Linux常见面试题
Mar 18 #面试题
ShellScript面试题一则-ShellScript编程
Jun 24 #面试题
Linux文件系统类型
Feb 15 #面试题
Solaris操作系统的线程机制
Jul 28 #面试题
如何利用cmp命令比较文件
Sep 23 #面试题
You might like
在PHP中使用redis
2013/11/04 PHP
phpmyadmin出现Cannot start session without errors问题解决方法
2014/08/14 PHP
php操作xml入门之cdata区段
2015/01/23 PHP
php采集神器cURL使用方法详解
2016/02/19 PHP
php禁用函数设置及查看方法详解
2016/07/25 PHP
php PDO异常处理详解
2016/11/20 PHP
php实现购物车功能(以大苹果购物网为例)
2017/03/09 PHP
老生常谈PHP面向对象之命令模式(必看篇)
2017/05/24 PHP
28个JS验证函数收集
2010/03/02 Javascript
jsp js鼠标移动到指定区域显示选项卡离开时隐藏示例
2013/06/14 Javascript
二叉树的非递归后序遍历算法实例详解
2014/02/07 Javascript
nodejs中实现路由功能
2014/12/29 NodeJs
逻辑表达式中与或非的用法详解
2016/06/06 Javascript
利用Jquery队列实现根据输入数量显示的动画
2016/09/01 Javascript
基于AngularJS前端云组件最佳实践
2016/10/20 Javascript
js事件冒泡与事件捕获详解
2017/02/20 Javascript
vue-router路由参数刷新消失的问题解决方法
2017/06/17 Javascript
JavaScript变量作用域及内存问题实例分析
2019/06/10 Javascript
React传值 组件传值 之间的关系详解
2019/08/26 Javascript
在vue项目中promise解决回调地狱和并发请求的问题
2020/11/09 Javascript
python logging类库使用例子
2014/11/22 Python
深入理解NumPy简明教程---数组3(组合)
2016/12/17 Python
python排序函数sort()与sorted()的区别
2018/09/18 Python
使用Python脚本zabbix自定义key监控oracle连接状态
2019/08/28 Python
tensorflow没有output结点,存储成pb文件的例子
2020/01/04 Python
Python3爬虫关于识别检验滑动验证码的实例
2020/07/30 Python
CSS3 实现发光边框特效
2020/11/11 HTML / CSS
西班牙英格列斯百货官网:El Corte Inglés
2016/09/25 全球购物
如何现实servlet的单线程模式
2014/08/05 面试题
小学生家长寄语
2014/04/02 职场文书
机关出纳岗位职责
2014/04/03 职场文书
医德医风演讲稿
2014/05/20 职场文书
2014年纳税评估工作总结
2014/12/23 职场文书
火锅店的开业营销方案范本!
2019/07/05 职场文书
Go 语言下基于Redis分布式锁的实现方式
2021/06/28 Golang
react 路由Link配置详解
2021/11/11 Javascript