readme.txt
vFileSystem 1.0
===========================
I. Overview
vFileSystem is a UNIX-like file system with a hierarchical directory structure.
Users can browse the directory structure, create and delete new files as well as
directory.
II. System Required
The current version is developed and validated on Linux operating system,
specifically Ubuntu 9.04. You may use similar operating system to run it. Make
sure "make" and "g++" are installed on your machine. We DO NOT provide such
packages, if you are working on Ubuntu 9.04, try the following command:
~$ sudo apt-get install build-essentials
Pay Attention:
Windows with Cygwin is NOT compatible for this version!!!
III. Usage
1. Package Structure
The vFileSystem package contains the basic tools for file system operations and
source codes.
1) vhdd: A fixed size large file representing virtual hard disk drive.
Initialized content is '~' in vhdd. So '~' is not allowed to use as the content
in vFileSystem.
2) Source code for the vFilesystem implementations:
Blocks : Blocks functions implementation
Filesystem : File functions implementation
Types : Directory, Inode and Blocks definition
Interpreter : Shell-like interpreter
Makefile : Makefiles for vFileSystem
test.c : vShell entry point
3) Testing files:
Input
: Reading commands from
Out
: Write output into
input.txt
: Sample import file
2. Build vFileSystem
To compile the programs of vFileSystem, simply use Makefile to compile all the
programs.
Command in Linux Shell: make clean; make
3. Run vShell
After building, type command: ./vShell in Linux Shell to run vFileSystem.
"</root>%" indicates you have entered vFileSystem.
4. Supported Shell Commands
1)mkfs: Make a new file system, i.e., format the disk so that it is ready for
other file system operations.
Example: </root>% mkfs
2)open <filename> <flag>: Open a file with the given <flag>, return a file
descriptor <fd> associated with this file. <flag>: 1: READ ONLY; 2: WRITE ONLY,
3: READ_WRITE.
Example: </root>% open a.txt r/w/rw/1/2/3
3)read <fd> <size>: Read <size> bytes from the file associated with <fd>, from
current file offset. The current file offset will move forward <size> bytes after
read.
Example: </root>% read 1024 10
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4)write <fd> <string>: Write <string> into file associated with <fd>, from
current file offset. The current file offset will move forward the size of the
string after write. Here <string> must be formatted as a string. If the end of
the file is reached, the size of the file will be increased.
Example: </root>% write 1024 "abcdefg"
5)seek <fd> <offset>: Move the current file offset associated with <fd> to a new
file offset at <offset>. The <offset> means the number of bytes from the
beginning of the file.
Example: </root>% seek 1024 100
6)close <fd>: Close the file associated with <fd>.
Example: </root>% close 1024
7)mkdir <dirname>: Create a sub-directory <dirname> under the current directory.
Example: </root>% mkdir test
8)rmdir <dirname>: Remove the sub-directory <dirname>. This directory has to be
empty when it is removed.
Example: </root>% rmdir test
9)cd <dirname>: Change the current directory to <dirname>.
Example: </root>% cd test
10)link <src> <dest>: Create a link named <dest> to an existing file or directory
named <src>. Note that <dest> and <src> may not be in the same directory. Both
<src> and <dest> are files, not directories.
Example: </root>% link a.txt b.txt
11)unlink <name>: Remove a link to the name. (When link count drop to 0, delete
the file).
Example: </root>% unlink a.txt
12)stat <name>: Show the status of the file or directory with name <name>. It
displays its inode information; whether it is a file or directory; its link
count; size of the file/directory; number of blocks allocated; date modified;
items it contains.
Example: </root>% stat a.txt
13)ls: Show the content of the current directory. No parameters need to be
supported.
Example: </root>% ls
14)cat <filename>: Show the content of the file.
Example: </root>% cat a.txt
15)cp <src> <dest>: Copy the file from a source location to the destination
location. Note that <src> and <dest> may not be in the same directory. If the
<dest> already exists, the program should report an error.
Example: </root>% cp a.txt c.txt
16)tree: List the contents of the current directory in a tree-format. For each
file listed, its date file size should be included.
Example: </root>% tree
It returns:
root->
| test->
| | cs560->
| | | a.txt
| mouse->
| | b.txt
| home->
| | c.txt
17)import <srcname> <destname>: Import a file from the host machine file system
to the current directory.
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Example: </root>% import /home/test/input.txt a.txt
18)export <srcname> <destname>: Export a file from the current directory to the
host machine file system.
Example: </root>% export a.txt /home/test/output.txt
19)q / e / quit / exit: Quit the vFileSystem.
Example: </root>% q
20)redirection: sh < <input file> > <output file>
Example: </root>% sh < input.txt > output.txt
21)pwd: Check the current working directory
Example: </root>% pwd
5. File Operation Attention
User operates file MUST follow the flow: open file -> operate file -> close file,
in case of error.
6. Cache
This function enables caching data blocks of files in memory.
is invoked, such as read or write, the system call will go to
data blocks first and handles cache miss with LRU replacement
is also maintained. A simple LRU 4 frame paging out algorithm
page out.
IV. Contact
Jilong Liao: jliao2@utk.edu
Chi Zhang:
czhang24@utk.edu
V. Download Source Code
http://web.eecs.utk.edu/~czhang24/projects/vShell.tar.gz
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While a file access
cache to look for
policy. Consistence
is used in cache to