Lab 10

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Lab 10

(Chapter 10)

 

 


 

Learning Objectives

1.      To learn how to use regular expressions

2.      To learn how to compress and decompress files

3.      To learn how to sort ‘text’ files

4.      To learn how to search ‘text’ files for expressions, strings, and patterns and how to search for the locations of commands in a UNIX system

5.      To learn how to use database operations of cutting and pasting fields in ‘text’ files

6.      To learn how to uuencode and uudecode files

7.      To learn how to encrypt and decrypt files

Lab Work

In this lab, you will practice the advance file related commands in UNIX. For this purpose, you will use the files smallFile, mediumFile, and largeFile that you created in Lab 9.

  1. Log on to your UNIX system
  2. Make a copy of smallFile, called newSmallFile. Edit this file with vi and perform the following operations on the file while you edit it. Save changes in the file and show the resultant file.
    1. Give the command for replacing all occurrences of Davis or davis with David.

 

 

    1. Give the command for replacing all occurrences of period (.) with colon (:).

 

 

    1. Insert a few spaces at the beginning of some lines. Saves the changes and then use a command to remove spaces at the beginning of all the lines. Show the command that you used for accomplishing this task.

 

 

  1. Display sizes of midiumFile and largeFile. Compress mediumFile and largeFile with gzip. What are the names of compressed files? Show sizes of compressed and uncompressed files, along with their compression ratios. If your system has the zmore command, use it to display the compressed version of mediumFile. Uncompress the two compressed files. Show your session.

 

 

 

 

  1. In Lab 9 task 6, you created an executable file called generate. Show the type of data stored in this file and its long listing. Compress the file and show long listings of the compressed file and the file that contains the original data. Execute the compressed file to confirm that it can still execute. Uncompress the file and show its long listing. Show your session.

 

 

 

 

 

 

 

 

 

 

 

 

 

5.      Sort data in newSmallFile by using GPA as the sort key. Ignore the leading white spaces between fields. Show your session.

 

 

 

 

 

 

 

6.      Search your home directory and display pathnames of all HTML and C program files (i.e., files having .html, .htm, or .c extensions). Terminate your command line with 2> /dev/null | more in order to ignore error messages and paginate output of the command (we will learn more about this in Chapter 12). Show your session.

 

 

 

 

 

 

 

7.      Search your home directory and remove all ‘core’ files and files with .o extensions. The command should prompt you before deleting a file. Terminate your command line with 2> /dev/null in order to ignore error messages. Show your session.

 

 

 

 

8.      Where are the following commands located: ftp, ssh, tar, telnet, passwd, and find? Show the commandline you used to obtain your answer.

 

 

 

 

9.      Use the following smallFile (an enhanced version of the previous smallFile) and perform the following tasks:

$ more smallFile

John    Doe     ECE     3.54    doe@jd.home.org 111.222.3333

James   Davis   ECE     3.71    davis@jd.work.org       111.222.1111

Al      Davis   CS      2.63    davis@a.lakers.org      111.222.2222

Ahmad   Rashid  MBA     3.74    ahmad@mba.org   111.222.4444

Sam     Chu     ECE     3.68    chu@sam.ab.com  111.222.5555

Arun    Roy     SS      3.06    roy@ss.arts.edu 111.222.8888

Rick    Marsh   CS      2.34    marsh@a.b.org   111.222.6666

James   Adam    CS      2.77    jadam@a.b.org   111.222.7777

Art     Pohm    ECE     4.00    pohm@ap.a.org   111.222.9999

John    Clark   ECE     2.68    clark@xyz.ab.com        111.111.5555

Nabeel  Ali     EE      3.56    ali@ee.eng.edu  111.111.8888

Tom     Nelson  ECE     3.81    nelson@tn.abc.org       111.111.6666

Pat     King    SS      2.77    king@pk.xyz.org 111.111.7777

Jake    Zulu    CS      3.00    zulu@jz.sa.org  111.111.9999

John    Lee     EE      2.64    jlee@j.lee.com  111.111.2222

Sunil   Raj     ECE     3.36    raj@sr.cs.edu   111.111.3333

Charles Right   EECS    3.31    right@cr.abc.edu        111.111.4444

Diane   Rover   ECE     3.87    rover@dr.xyz.edu        111.111.5555

Aziz    Inan    EECS    3.75    ainan@ai.abc.edu        111.111.1111

Lu      John    CS      3.06    lu.john@xyz.org 111.333.1111

Lee     Chow    EE      3.74    chow@lc.www.ord 111.333.2222

Adam    Giles   SS      2.54    giles@cric.org  111.333.3333

Andy    John    EECS    3.98    john@aj.ece.edu 111.333.4444

$

a.       Display lines, with line numbers, records of Computer Science majors. Show your session.

 

 

b.      Display lines, with line numbers, for students whose first name is John. Show your session.

 

 

c.       Display lines, with line numbers, for students whose first or last name is Lee. Show Show your session.

 

 

d.      Display lines for students whose e-mail addresses end with .org. Show your session.

 

 

e.       Display lines for students with GPA above 3.69 but less than 4.0. Show your session.

 

 

f.        Display lines for Computer Science students with GPA 3.5 or above but less than 4.0. Show your session.

 

 

10.  Use the cut and paste commands to construct and display a table that contains four fields: first name, last name, GPA, and academic major. Show your session.

 

 

 

 

 

 

 

 

 

 

 

 

11.  Show the step needed to uuencode the generate file created in Lab 9. Display the first and last five lines of the uuencoded version of the file. How would you uudecode the uuencoded file and recover the original generate file? Show your session.

 

 

 

 

 

 

 

 

 

 

 

 

12.  The file smallFile contains confidential student data. We would like to save an encrypted version of the file and remove the text version from our file system structure. Perform this task. Show the steps needed to decrypt the encrypted file. Show your session.

 

 

 

 

 

 

13.  Log out.

 

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This page was last modified September 26, 2004
wmorales@pcc.edu