Continuing the first part, you are asking to implement boards and posts in the Bulletin Board System (BBS). The server should be multiprocessing / multithreading, and the following function will be connected by TCP. Your posts should maintain in the shared memory, that is, all operations related to posts should be done in shared memory, and other operations have no limitation.
Requirement
The service accepts the following commands and at least 10 clients:
When client enter command incompletely, that is, missing parameters, the server should show command format for client.
If command is in the right format, the first failure message will have the higher priority, for example of the “create-board” command, the user didn’t login, then the result should be “Please login first”.
|
Command format |
Description |
Result |
|
|
create-board <name> |
Create a board which named <name>. <name> must be unique. If Board’s name is already used, show failed message, otherwise it is success. Must be logged in when creating board’s name. There is no limit to do the operation by shared memory or database. |
Success |
Create board successfully. |
|
Fail (1) |
Please login first. |
||
|
Fail (2) |
Board already exists. |
||
|
create-post <board-name> –title <title> –content <content> |
Create a post which title is <title> and content is <content>. Use –title and –content to separate titles and content. <title> can have space but only in one line. <content> can have space, and key in <br> to indicate a new line. Assign a unique serial number to each post. The serial number will start from 1 and increase by creating post. |
Success |
Create post successfully. |
|
Fail (1) |
Please login first. |
||
|
Fail (2) |
Board does not exist. |
||
|
list-board |
List all boards in BBS. There is no limit to do the operation by shared memory or database. |
Index Name Moderator <Index1> <Name1> <Moderator1> |
|
|
list-post <board-name> |
List all posts in a board named <board-name> Do the operation by shared memory. |
Success |
|
|
S/N Title Author Date |
|||
|
Fail |
Board does not exist. |
||
|
read <post-S/N> |
Show the post which S/N is <post-S/N>. Do the operation by shared memory. |
Success |
Author: <Author1> Title: <Title1> Date: <Date1> <content> |
|
Fail |
Post does not exist. |
||
|
delete-post <post-S/N> |
Delete the post which S/N is <post-S/N>. Only the post owner can delete the post. If the user is not the post owner, show failed message, otherwise it is success. Do the operation by shared memory. |
Success |
Delete successfully. |
|
Fail (1) |
Please login first. |
||
|
Fail (2) |
Post does not exist. |
||
|
Fail (3) |
Not the post owner. |
||
|
update-post <post-S/N> –title/content <new> |
Update the post which S/N is <post-S/N>. Use — to decide which to modify, title or content, and replaced by <new>. Only the post owner can update the post. If the user is not the post owner, show failed message, otherwise it is success. Do the operation by shared memory. |
Success |
Update successfully. |
|
Fail (1) |
Please login first. |
||
|
Fail (2) |
Post does not exist. |
||
|
Fail (3) |
Not the post owner. |
||
|
comment <post-S/N> <comment> |
Leave a comment <comment> at the post which S/N is <post-S/N>. Do the operation by shared memory. |
Success |
Comment successfully. |
|
Fail (1) |
Please login first. |
||
|
Fail (2) |
Post does not exist. |
||
|
exit |
Close connection. |
||
Scenario
bash$ client 127.0.0.1 7890
********************************
** Welcome to the BBS server. **
********************************
% create-board NP_HW
Please login first.
% register Bob [email protected] 123456
Register successfully.
% register Sam [email protected] 654321
Register successfully.
% login Bob 123456
Welcome, Bob.
% create-board NP_HW
Create board successfully.
% create-board NP_HW
Board already exists.
% create-board OS_HW
Create board successfully.
% create-board FF
Create board successfully.
% list-board
Index
1
2
3
%
Name Moderator NP_HW Bob OS_HW Bob FF_HW Bob
create-post NCTU –title About NP HW_2 –content Help!<br>I have some problem! Board does not exist.
% create-post
NP_HW
–title About NP HW_2 –content Help!<br>I have some problem!
Create post successfully.
% create-post NP_HW –title HW_3 –content Ask!<br>Is NP HW_3 Released? Create post successfully.
% list-post NP
Board does not exist. % list-post NP_HW
S/N
1
2
% read 100
Post does not exist. % read 1
Date 10/26 10/26
Title Author About NP HW_2 Bob HW_3 Bob
Author: Bob
Title: About NP HW_2
Date: 10/26
—
Help!
I have some problem!
—
% update-post 100 –title NP HW_2 Post does not exist.
% update-post 1 –title NP HW_2 Update successfully.
% read 1
Author: Bob
Title: NP HW_2
Date: 10/26
—
Help!
I have some problem!
—
% logout
Bye, Bob.
% login Sam 654321
Welcome, Sam.
% update-post 1 –content Ha! ha! ha! Not the post owner.
% delete-post 1
Not the post owner.
Post does not exist.
% comment 1 Ha! ha! ha!
Comment successfully.
% read 1
Author: Bob
Title: NP HW_2
Date: 10/26
—
Help!
I have some problem!
—
Sam: Ha! ha! ha!
% create-board Hello
Create board successfully.
% list-board
Index Name Moderator
|
% comment |
100 Ha! ha! ha! |
- 1 NP_HW Bob
- 2 OS_HW Bob
- 3 FF_HW Bob
- 4 Hello Sam
% logout
Bye, Sam.
% login Bob 123456 Welcome, Bob.
% delete-post 1 Delete successfully. % read 1
Post does not exist. % logout
Bye, Bob.
% exit
Grade (100%)
⚫ TCP connection. – (5%)
⚫ Multiprocessing / Multithreading. – (10%) ⚫ Shared memory. – (10%)
⚫ create-board command. – (10%)
⚫ create-post command. – (10%)
⚫ list-board command. – (10%)
⚫ list-post command. – (10%)
⚫ read command. – (10%)
⚫ delete-post command. – (5%) ⚫ update-post command. – (10%) ⚫ comment command. – (10%)
Submission
Please upload a zip file called “hw2_student_id.zip”, for example, “hw2_123456789.zip” that includes your source code (server and client) and executable file (alternative). If you are using python, it might be no executable file. You can submit your source code only, but you should make sure that you can run the bash script by your python file. You should upload on time! Submission that don’t follow the rule will get 20% punishment on the grade. You will get 0 points on this project for plagiarism. Please don’t copy-paste any code!
Demo
There is script called nphw2.sh. Before you submit your executable to New E3, please check whether your code is able to run by the script. As same as homework1 we will provide a script called npdemo2.sh for you to download the script and run it. If you don’t know how to run npdemo2.sh at demo time, TA will take 10 points off. For those don’t have a laptop, we provide a VirtualBox environment (link on New E3) for you to run your code, or you can use remote desktop this time, the software will be TeamViewer tentative. You can’t modify your code after the deadline of submission. TA will ask some questions about your code. If you can’t answer TA’s questions or you are not clear on your code, TA will take 10 points off for each question. You can execute the script by following, but there are no regulations:
Change mode of nphw2.sh: chmod u+x nphw2.sh
- ⚫ C/C++: ./nphw2.sh ./client 127.0.0.1 7890
- ⚫ Java: ./nphw2.sh “java client” 127.0.0.1 7890
- ⚫ Python2: ./nphw2.sh “python client.py” 127.0.0.1 7890
- ⚫ Python3: ./nphw2.sh “python3 client.py” 127.0.0.1 7890
Reference
- C/C++Socket
- SQLite C/C++ Interface
- LinuxsocketSELECT
- Linuxsemaphore
- Linuxfork
