Operating system: The operating system is an organized group pf ... - DOC

							COS 231: Introduction to UNIX – Spring 2002           Midterm Exam - preparation                      Mar 05,2002

Midterm Exam – preparation                                                                     05 March 2002


1. Write command lines to:
a. Display the long listing of all files including
   the subdirectories in /usr/home/                          $ ...................................
b. You have two files: f001 and f002 in your home
   directory. Write the command which will modify the
   content of file f002. The content of f002 should be:
   <content of f002> <content of f001> <content of f002>: $ ..............................
c. Make a symbolic link (named locbin) in your home
   directory to locbin directory, which is two levels up from
   your home:                                                $ .............................
d. What command will tell you your User Id (uid) and
   name and your Group ID (gid) and name?                    $ ……………………
e. What command allows you to change your password? $ …………………….
f. Give the command that prints the name of the current
   directory file                                            $ ………………………

2.   If the following command lines are legal?
     Write True or False.

a.   $ cat f001 /usr/vak/cos231/f002 > /usr
b.   $ ls –l | sort | cat > f002
c.   $ mkdir ./test1; cp f001 f002 ./test1
d.   $ rm –i f*[1-5,r-z]
e.   $ mv ?*[abcd]? ~

3. Who can (owner, group, other, and all) :
      (a)         execute the following files ?:
-rwx------        2 vak cos_231 17568                 Sep 21     10:56     fil_001     . . . . . .

---x--xrw-        2   vak     cos_231         17568   Sep 21     10:56     fil_001     . . . . . .

         (b)      read the following files?:

--wx-wx-wx        2   vak     cos_231         17568   Sep 21     10:56     fil_001     . . . . . .

-rwxr---w-        2   vak     cos_231         17568   Sep 21     10:56     fil_001     . . . . . .

         (c)      write the following files?:

dr-xr-xr-x        2   vak     cos_231         17568   Sep 21     10:56     fil_001     . . . . . .

-rwxrw---x        2   vak     cos_231         17568   Sep 21     10:56     fil_001     . . . . . .




V. Karagiozov                                                                                                       1/3
COS 231: Introduction to UNIX – Spring 2002             Midterm Exam - preparation                     Mar 05,2002

4. Give group file name (wild card), if it is possible:

a. all files that have a "p" as a second and "d" or
   "F" as a last char.
b. all files that start with a "p", have "d"
   somewhere inside and the last is "u".
c. all files that start with a digit or char "p" and
   end with a two digits.
d. all files that start with an uppercase letter and
   are only three char long.
e. all files that have an uppercase letter
   somewhere inside their names

.
6. Given the following file:
In fact, information on file ownership, permissions, and so forth is
provided only by filesystem types that are meant to be used for
storing Linux files. For filesystem types that don't store this
information, the kernel drivers used to access these filesystems
"fake" the information.

Perform the following sequience of vi commands

j    dd   k dd j     dd    “2p      Esc       :s/file/pile/g    H       dd          dd   6Wd$

What will be the final content of the file?


7.   You are user syyy. Write the command(s) to execute the script filescript
     -rw-r--r--            1        syyy group                   1234 Oct 8 8:23                 filescript

8. Is the following a relative or absolute filename reference:                        ./330/assn1
9. What will output this script if executed?
              set `w|grep USER`
              echo $*
              echo $2, $1, $8
The sample of the output from w command:
          10:01pm     up 24 days, 7:35, 4 users, load                         average: 0.13, 0.05,   0.02
          USER        TTY      FROM            LOGIN@                          IDLE   JCPU   PCPU    WHAT
          volin       pts/2    193.68.137.186  8:43pm                         0.00s 0.15s 0.02s      w
          tsvetk      pts/4    193.68.141.13   9:58pm                         2:19   0.04s 0.01s     -bash
          paulp       pts/3    193.68.141.158 12:31pm                         4:28m 0.10s 0.10s      -bash

10. Give the command that lists only background processes running
    on the current terminal.

11. You have 3 jobs in the background. Give the command and argument to bring the job
    whose job_id is 2 to the foreground.

12. Job 1 is suspended. Restart it in the background


V. Karagiozov                                                                                                        2/3
COS 231: Introduction to UNIX – Spring 2002         Midterm Exam - preparation                   Mar 05,2002

13. Given the following information:             cmd=”echo oops” What will the following print
             a. echo '$cmd'            # single quotes
             b. echo "$cmd"               # double quotes
             c. echo `$cmd`             # agraves


14. If the variable cmd set up as follows: cmd="ls – l"
    What command can run the commands stored in the variable cmd?


Suppose the file testreg contains 7 lines, three of them are empty lines:

         Line1                      aaa
         Line2
         Line3                      dcdc
         Line4
         Line5                      cccc
         Line6
         Line7                      fffff

15. What these commands will output?

grep     '.*' testreg |wc –l
grep     'a?*' testreg |wc –l
grep     '..*' testreg |wc –l
grep     'v*g*' testreg |wc –l
grep     '[a|c]' testreg |wc –l

16. What this pattern matches:                      \<the

17. What this pattern matches:                      the\>
18. What will be printed by this command? (              is a space)

    $ echo   Hey!              What's next?           Mike's #1 friend has $$.

19. What this pattern matches:                ^bag$
20. Are these two commands equivalent?
       $ cat food 2>&1 >file
       $ cat food >file 2>&1




V. Karagiozov                                                                                                  3/3