Name: ___Solutions__________________ SID: ____Solutions____________

CSci 414/553: Unix Network Prog & Software Development

Test 1, Spring 2008

Answer the following questions in the space provided, or as instructed by editing and adding files to your student account. Please be write clearly and make clear your final solution to a question if you make changes or corrections (pencils are recommended). Partial credit will be given if and where possible, so show your work where appropriate. This test is open book / open source material, you may use any source materials you like and find helpful for this class. However, this is an individual test, no cell phones, IM or other collaboration will be allowed during the test.

1. (6 pts) Match the following tools/commands with the description of their purpose (you can draw lines and/or match the number with the letter).

1) rm	L	a) symbolic debugger	3
2) ls	H	b) create or extract archives of directory structures	6
3) gdb	A	c) concatenate files and print on standard output	7
4) grep	E	d) task automation and system build tool	12
5) chmod	I	e) print line matching a regular expression pattern	4
6) tar	B	f) c source code compiler	8
7) cat	C	g) revision control system	11
8) gcc	F	h) list directory contents	2
9) man	K	i) change file access permissions	5
10) cd	J	j) change working directory	10
11) svn	G	k) read online reference manuals	9
12) make	D	l) remove files or directories	1

2. (2 pts) Which of the following problems or tasks does a version control system like subversion solve for you?

1. Allows you to automate repetitive tasks

2. Allows multiple collaborators to share and sync changes with one another

3. Allows you to undo changes in time, e.g. see the past history of changes done to a file

4. Allows you to symbolically debug a program in a more systematic way than using print statements.

Answer(s) (choose all that apply): ______B, C______________

3. (4 pts) If you run the following subversion command and see this output:

[harry@nisl lab04]$ svn status

! wc.py

M palindrome.py

A goodbye.py

C reverse.py

What does the ! indicate about the wc.py file? ________File is missing in local working copy of repository

What does the M indicate about the palindrome.py file? File has been modified

What does the A indicate about the goodbye.py file? ___File has been added to repository

What does the C indicate about the reverse.py file? ____File is in conflict

4. (2 pts) The pipe command ( | ) is used to:

1. Redirect the output of a command into a new file

2. Renumber the output of a command

3. Run two commands concurrently

4. Redirect the output of a command into the input of another command

Answer(s) (choose all that apply): ___D_____

5. (3 pts) Given the following directory listing:

[root@nisl sbin]# ls -al rrestore service

lrwxrwxrwx 1 root root 7 Jun 26 2007 rrestore -> restore

-rwxr-xr-- 1 root aturing 1744 Nov 28 2006 service

What type of file is rrestore? ____symbolic link__________________________

Who has permission to delete the service command file? _root (the owner of the file)

Who has permission to execute the service command? ___root (the owner) and members of the aturing group

6. (6 pts) Mark the following as examples of either Relative path names (R) or Absolute path names (A)

1. test.py _Relative_

2. ../../bin/script.py _Relative_

3. /usr/local/lib/libabs.a _Absolute_

4. ~/work/project/file.txt _Relative_

5. / _Absolute_

6. ./dat2csv.py _Relative_

7. (3 pts) What three things must be done in order to make an interpretable script, such as a file of Python or Perl code, be executable?

1. Set execute permission for the file (e.g. chmod +x)

2. Specify appropriate interpreter for file (e.g. using #! method for example on Linux)

3. Locate the script (e.g. by adding to your PATH, or specifying an absolute or relative full path name of the script)

8. (3 pts) Given the following contents of the file animals.txt, how would you use both input and output redirection and the sort command to create a new file called animals-sorted.txt that contains the same contents as in animals.txt by sorted by alphabetical order?

[harry@nisl ~]$ cat animals.txt

elephant

kangaroo

dog

bird

mongoose

[harry@nisl ~]$ cat animals.txt | sort > animals-sorted.txt

9. (6 pts) Given the following Makefile:

------------------------------------------ Makefile ------------------------------------

CC = gcc

CFLAGS = -g -O2 -D_REENTRANT -Wall

LIBS = ../libunp.a -lpthread

LIBUNP_NAME = ../libunp.a

LIBGAI_OBJS = getaddrinfo.o getnameinfo.o freeaddrinfo.o gai_strerror.o ga_aistruct.o \

ga_clone.o ga_echeck.o ga_nsearch.o ga_port.o ga_serv.o ga_unix.o gn_ipv46.o

PROGS = testga test1

CLEANFILES = core core.* *.core *.o temp.* *.out typescript* \

*.lc *.lh *.bsdi *.sparc *.uw

all: ${LIBGAI_OBJS}

ar rv ${LIBUNP_NAME} $?

testga: testga.o

${CC} ${CFLAGS} -o $@ testga.o ${LIBS}

test1: test1.o

${CC} ${CFLAGS} -o $@ test1.o ${LIBS}

%.o: %.c

${CC} -c -o $@ $<

clean:

rm -f ${PROGS} ${CLEANFILES}

------------------------------------------ Makefile ------------------------------------

What is the default target of this makefile? __all______________________________________________________

What does the default target do? _Creates the static archive libunp.a, and compiles any out of date object files that are part of the library.

What are the prerequisites of the testga target? __testga.o______________________________________________

CC and CFLAGS are examples of

(a) automatic varibles (b) make macro variables (c) targets (d) actions (e) prerequisites? ______B______________________

$@ and $< are examples of

(a) automatic varibles (b) make macro variables (c) targets (d) actions (e) prerequisites? ______A______________________

If test1.c is in the current directory and has been modified, what actions would you expect to take place if

[user@nisl ~]$ make test1 is invoked? __

gcc -c -o test1.o test1.c

gcc -g -O2 -D_REENTRANT -wall -o test1 test1.o ../libunp.a -lpthread

10. (3 pts) What is displayed when the following python script is run as shown:

----- argscript.py contents -----

#!/usr/bin/env python

import sys

for arg in sys.argv:

print arg

---------------------------------

[harry@nisl ~]$ ./argscript.py arg1 -flag1 arg2

./argscript.py

arg1

-flag1

arg2

11. (2 pts) We discussed and frequently used two special directory to specify relative path names from the command line and in Makefiles and scripts. Briefly, what do these two special directory names refer to?

1. . __the current working directory ____________________________

2. .. __the parent directory (relative to the current working directory)__

12. (3 pts) Briefly describe what each wildcard character does when used with the bash shell to match file names:

1. * ____match 0 or more of any character_______________________________

2. ? ____match any single character_____________________________________

3. [] ____match any single character among choices (e.g. if [aeiou] match either an a, an e, an i, an o or a u)

13. (3 pts) Given the following directory listing, what will be displayed by executing the given directory listing command:

[dharter@chaos shultznn] $ ls -al

total 120

drwxr-xr-x 2 dharter dharter 4096 2007-02-26 16:51 .

drwxr-xr-x 9 dharter dharter 4096 2007-02-21 09:35 ..

-rwxr-xr-x 1 dharter dharter 26541 2007-02-26 16:51 backpropsim

-rw-r--r-- 1 dharter dharter 2020 2007-02-23 15:42 backpropsim.c

-rw-r--r-- 1 dharter dharter 4440 2007-02-26 16:51 backpropsim.o

-rw-r--r-- 1 dharter dharter 149 2007-02-23 15:35 Debug.h

-rw-r--r-- 1 dharter dharter 13605 2007-02-23 15:38 Layer.c

-rw-r--r-- 1 dharter dharter 617 2007-02-23 11:05 Layer.h

-rw-r--r-- 1 dharter dharter 14044 2007-02-26 16:51 Layer.o

-rw-r--r-- 1 dharter dharter 584 2007-02-26 16:50 Makefile

-rw-r--r-- 1 dharter dharter 1834 2007-02-23 15:39 Pattern.c

-rw-r--r-- 1 dharter dharter 392 2007-02-22 11:10 Pattern.h

-rw-r--r-- 1 dharter dharter 5724 2007-02-26 16:51 Pattern.o

-rw-r--r-- 1 dharter dharter 499 2007-02-21 11:14 Random.c

-rw-r--r-- 1 dharter dharter 193 2007-02-21 11:55 Random.h

-rw-r--r-- 1 dharter dharter 3140 2007-02-26 16:51 Random.o

[dharter@chaos shultznn]$ ls [LP]*.[hc]

Layer.c Layer.c Pattern.c Pattern .h

14. (3 pts) What are the 3 I/O connections that every process in Unix has to the outside world when it is created, and what are these connected to by default (don't forget this second part, does the I/O go to a printer for example by default, or where)?

1. _standard input connected to the keyboard__

2. _standard output connected to the terminal_

3. _standard error also connected to the terminal

15. (1 pts) The following use of pipes is illegal because you can only pipe 2 commands together at most:

$ grep 'Title' spells.txt | sort | uniq -c | sort -n -r | head -10 > popular_spells.txt

a) True b) False

16. (1 pts) Any program that reads from standard input and writes to standard output can use I/O redirection and pipes

a) True b) False

17. (1 pts) A program that reads from standard input, does some manipulation, then writes results to standard output is called a:

____Filter_______________ __________________________

18. (1 pts) If you are using the bash shell, which file should you edit in order to have variables or aliases set automatically for you every time you log in?

__~/.bashrc________________________________________

19. (6 pts) Assume that there is a subversion repository that you have modify access to at the url location http://magicco.org/repo

What subversion command would you use to check out a working copy of the magicco repo to a directory calld magiccorepo in your home directory?

[user@nisl ~]$ svn co http://magicco.org/repo magiccorepo

If you are now in the magiccorepo working copy directory, what command would you use to synchronize your working copy of the repository with the most recent revision that has been checked in?

[user@nisl ~]$ svn update

What command would you run to add a new file named spells.txt in current directory to be under revision control?

[user@nisl ~]$ svn add spells.txt

What command would you run to see all of the logged history of updates and changes to the repository?

[user@nisl ~]$ svn log

What command would you use to remove a file named spellusers.txt that is currently under repository control from the repository?

[user@nisl ~]$ svm rm spellusers.txt

What command would you use to send your changes to the repository and create a new revision?

[user@nisl ~]$ svi ci

20. (8 pts) Given the following Makefile:

------------------------------- Makefile ---------------------------------

element_summary.csv: gold.csv lead.csv silver.csv

summarizecsv gold.csv lead.csv silver.csv > element_summary.csv

gold.csv: gold.dat

dat2csv gold.dat > gold.csv

lead.csv: lead.dat

dat2csv lead.dat > lead.csv

silver.csv: silver.dat

dat2csv silver.dat > silver.csv

clean:

rm -v *.dat

------------------------------- Makefile ---------------------------------

And also with the following dates/times and files in the current directory:

[dharter@chaos tests]$ ls -al

total 76

drwxr-xr-x 2 dharter dharter 4096 2007-03-13 13:41 .

drwxr-xr-x 5 dharter dharter 4096 2007-03-13 10:50 ..

-rw-r--r-- 1 dharter dharter 54 2007-03-13 13:25 element_summary.csv

-rw-r--r-- 1 dharter dharter 27 2007-03-13 13:38 gold.dat

-rw-r--r-- 1 dharter dharter 65 2007-03-13 13:40 lead.csv

-rw-r--r-- 1 dharter dharter 101 2007-03-13 13:41 lead.dat

-rw-r--r-- 1 dharter dharter 288 2007-03-13 13:40 Makefile

-rw-r--r-- 1 dharter dharter 40 2007-03-13 13:40 silver.csv

-rw-r--r-- 1 dharter dharter 67 2007-03-13 13:38 silver.dat

Draw a file dependency tree of the targets/prerequisites defined by this Makefile:

20. (continued from question on previous page)

What commands will be be run by make when we do the following. Be careful, you need to examine the dates/time stamps as well as the file dependencies to determine which commands will be run. Remember, that make will only run the actions for targets that are out of date based on their dependencies.

[dharter@chaos tests]$ make

dat2csv gold.dat > gold.csv

dat2csv lead.dat > lead.csv

# silver.csv is already up to date (newer) than its dependency, so will not be rebuilt)

summarizecsv gold.dat lead.dat silver.dat > element_summary.csv

Whoops, what is wrong with the make file that causes the following problem? How would you fix the problem?

[dharter@chaos tests]$ make clean

rm -v *.dat

removed `gold.dat'

removed `lead.dat'

removed `silver.dat'

[dharter@chaos tests]$ make

make: *** No rule to make target `gold.dat', needed by `gold.csv'. Stop.

The clean target should remove product files, not source files:

clean:

rm -v *.csv

21. (5 pts) In Python, what data type or data structure is held in each of the following variables. Possible answers include Boolean, String, List, Dictionary, Tuple, Integer, ImaginaryNumber, Function

items = [1, 2, 3] __List_________________

user = “Derek” __String_______________

dates = {“newton”: 1942, “einstein”: 1882} __Dictionary___________

point = (8,2) __Tuple________________

flag = True __Boolean______________

22. (10 pts) Given this variable assignment in python:

vals = [5, 20, 8, “red”, “green”, “blue”]

Write two versions of a Python loop that will print out each item in the variable on a separate line to standard output, one using indexes and one that doesn't use indexes. You should write this as a simple Python script, name the script loop.py, add it to your test directory in your repository working copy, and check the file in.

Example solutions are available checked in to example student harry repository. Do a

$ svn co http://nisl.tamu-commerce.edu/repo/csci553/harry/test harrytest

to see the solution

23. (2 pts) Given the following variable declaration in Python:

element = “hydrogen”

What is displayed on standard output if we do the following (remember that it helps here to think of the indices as being between elements):

print element[1:3], element[:2], element[4:-1]

yd hg oge

24. (4 pts) What is displayed after we execute the following Python statements:

birthday = {

'Newton' : 1642,

'Darwin' : 1809,

'Turing' : 1912

}

del birthday['Turing']

birthday['Einstein'] = 1888

names = birthday.keys()

names.sort()

for name in names:

print name, birthday[name]

Darwin 1809

Einstein 1888

Turing 1912

25. (12 pts) The following should be done in your student account. Copy the test script called TestLastUpper.py from /home/csci553/classfiles/TestLastUpper.py, add it to your test directory of your repository working copy, and check it in when you have completed the question.

You are to implement and test a function that accepts a single string as input, and returns a boolean result. The purpose of the function is to return true if the last (and only the last) character of the string is an upper case character. Currently the function does nothing, you need to provide the correct logic to implement the function as described.

Once you have implemented your function you should test it. A single test is already available for you in the script which tests a typical example where the function should return True:

isLastOnlyUpper('hellO') => True # test a true example

Once your function is working, you should add tests for all of the following as well, and make sure your function works for all of these cases:

isLastOnlyUpper('') => False # test the boundary condition of an empty string

isLastOnlyUpper('a') => False # test false boundary condition single character string

isLastOnlyUpper('A') => True # test true boundary condition single character string

isLastOnlyUpper('HellO') => False # test a false example

isLastOnlyUpper('hello') => False # a different failure case

Example solutions are available checked in to example student harry repository. Do a

$ svn co http://nisl.tamu-commerce.edu/repo/csci553/harry/test harrytest

to see the solution