Transcript Yun Zhang

Chapter 4 Application Software
Readings:
4.1 Software Basics
4.2 Using Software Systems
4.3 Batch Script Files
4.4 Databases
4.5 Software Engineering
Assessments:
Exercise 4
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4.1 Software Basics
• Exactly what is software?
Software consists of computer programs, support
modules, and data modules that work together to
provide a computer with the instructions and data
necessary for carrying out a specific type of task,
such as document production, video editing, or
Web browsing.
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• When you purchase a piece of software, you
own the physical medium on which it is
distributed, typically a diskette or CD.
However, the software itself is owned by the
author or copyright holder, and what you
may legally do with it is determined by the
license that was granted at the time of
purchase.
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4.2 Using Software Systems
• Software systems usually provide input
and control methods that can help users
accomplish their tasks quickly and
efficiently.
4.2.1 Lab: DOS Commands
DIR , TYPE , TREE , EXIT ……
path : \windows\system32
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4.2 Using Software Systems
• 4.2.2 Lab: Macros
– 宏定义与宏操作（例：WORD中定义宏和运行宏）
– 利用简单的语法，把常用的动作写成宏，当在工
作时，就可以直接利用事先编好的宏自动运行，
去完成某项特定的任务，而不必再重复相同的动
作
– 宏病毒：某种特殊功能的宏，感染WORD的通用
模板，使其带有某种自动功能，从而可能具有某
种破坏能力
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– It can reduce the amount of time required to
create a document.
– It can reduce the chance of entering
erroneous data.
– It can simplify a complicated set of
interactions, so that other people can
perform the operation without
understanding all of the details involved
with the application interface. You can even
place the name of the macro on the
application's menu or toolbar, as if you have
created a function that was not provided by
the application's developers
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4.2 Using Software Systems
• 4.2.3 Lab: Embedding Application Objects
– Object Linking and Embedding (OLE) is a
facility provided by more sophisticated
applications, and it requires operating system
support. The OLE facility allows data (typically
graphics or spreadsheets) that has been
created by any of a number of different
applications to be combined into a single
document file.
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4.3 Batch Script Files
• 4.3.1 Advanced Command-Line
Functions
• DOS Command Syntax
• Review of File System Commands
• Wildcard Characters
• Redirection and Piping
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DOS Command Syntax
• Each line begins with a command name or
program name.
• After the command name may come one or
more switches.
– A switch is written as a slash(/斜线) followed by a
letter.
– Switches can also take parameters, which are
separated from the switch by a colon(:冒号).
• Commands can also take arguments, such as
filenames or paths.
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DOS Command Syntax
• The /? switch tells a command to display
its Help entry.
• Typing del /? on the Windows Me
command line causes the following to
display:
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Examples
•
•
•
•
•
C:\>dir
C:\>dir /w
C:\>dir /o:n
C:\>dir c:\windows
C:\>dir /?
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Review of File System Commands
cd
Change the working directory.
md
Make a new directory.
rd
Remove an existing empty directory.
deltree
Remove an existing directory and its contents.
attrib
Change a file's attributes
copy
Make a copy of a file.
xcopy
Make a copy of files and sub-directories.
ren
Rename a file within a directory.
move
Move a file from one drive/directory to another.
del
Delete files.
dir
List files in a directory.
type
Display the contents of a text file.
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Wildcard Characters
• Certain commands accept a list of file
names. Rather than typing in an actual list,
it is often easier to use an asterisk ( * )
within a file name specification to get the
command processor to generate a list of
file names for us. An asterisk ( * ) acts as a
wildcard character that can match any
number of characters in a file name. Here
are some examples of an asterisk used as
a wildcard character with the dir command:
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Wildcard Characters
• List only those files and folders in the root folder
whose names start with "n":
dir c:\n*
• List only those files and folders in the root folder
whose names end with "n":
dir c:\*n
• List only those files and folders in the root folder
whose names contain an "n" anywhere:
dir c:\*n *
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Wildcard Characters
• List only those files in the root folder that
are of type DOC:
dir c:\*.doc
• List all files and folders in the root folder.
dir c:\*
In this last example the wildcard character
can be omitted; dir c:\ works just as well.
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Wildcard Characters
• There is another wildcard character that is
more specific—the question mark ( ? )
wildcard. The question mark wildcard
represents any one character. This means
that a character must exist in the spot
designated by a question mark wildcard.
Consider the following two commands:
• del c:\*.*
del c:\????????.???
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Redirection
– On a PC, the command processor
coordinates with the operating system to
redirect all data from the keyboard driver to
the Standard Input virtual device and all data
from the Standard Output virtual device to
the display driver. Redirection allows the
user to change this.
– The left angle bracket ( < ) is used to
redirect standard input, and the right angle
bracket ( > ) is used to redirect standard
output.
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Some examples of the use of
redirection
• List all files in the root folder to the printer
instead of the display:
dir c:\*.* >lpt:
• Create a new text file called "temp.txt"
containing a list of files in the root folder.
(Note: Nothing will appear on the display.):
dir c:\*.* >c:\temp.txt
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Some examples of the use of
redirection
• Run "program.exe" and have it get data from the
text file INPUT.DAT rather than the keyboard:
c:\program.exe <c:\input.dat
• Run "program.exe", have it get data from the
text file "input.dat" rather than the keyboard, and
display the output on the printer:
c:\program.exe <c:\input.dat >lpt:
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Some examples of the use of
redirection
– Another bit of syntax allows you to append
output to the end of a file—or else create the
file if it does not already exist
– dir c:\*.* >>c:\temp.txt
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Piping
• Piping is a function of the command
processor that links two commands
together via redirection: the output of the
first command becomes the input to the
second.
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Piping
• To pipe data from one command to
another as described above, the user
separates the two commands on the
command line with a vertical bar character
( | ).
• Display all the options of the dir command:
dir /? | more
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4.3.2 Batch File Commands
• Batch Files
• Commands
• Like Macros, which were discussed in
4.2.2 Lab: Macros, batch files automate
tasks.
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• Review of File System Commands
cd
Change the working directory.
md
Make a new directory.
rd
Remove an existing empty directory.
deltree
Remove an existing directory and its contents. (Use rd /s in Windows
NT/2000.)
attrib
Change a file's attributes (for example, read-only file, system file, hidden
file)
copy
Make a copy of a file.
xcopy
Make a copy of files and sub-directories.
ren
Rename a file within a directory.
move
Move a file from one drive/directory to another.
del
Delete files.
Warning: Files that are deleted in DOS or from the Command Window
cannot be restored.
dir
List files in a directory.
type
Display the contents of a text file.
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4.3 Batch Script Files
4.3.2 Batch File Commands
• Create a new Batch file
• Commands
• Rem , echo , echo. , @echo off , pause ,
:label , goto label , if exist filename
4.3.3 Lab: Creating a Batch File
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• Example---- swap.bat
REM Here is the source to SWAP file1 file2
@ECHO OFF
REM Remember that / precedes a switch.
REM Use HELP DEL or DEL /? to find out
about /Q
DEL/Q TEMP
MOVE %1 TEMP
MOVE %2 %1
MOVE TEMP %2
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4.3.2 Batch File Commands
• The following is a list of command-line features
commonly used in batch files:
• rem remark
This designates anything that follows the rem
command on the line (remark in our example) as
a comment.
• echo message
This command displays message to Standard
Output. The echo command can also be used
with output redirection to send a message to a
file. For example, echo starting stage three.
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4.3.2 Batch File Commands
• echo.
Notice the period ( . ) at the end of the
echo command. This is a special variation
of the echo command, which displays a
blank line to Standard Output.
• @echo off
This stops commands in the batch file
from being displayed to Standard Output.
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4.3.2 Batch File Commands
• pause
This command interrupts the execution of the
batch file and displays the message "Press any
key to continue...." Execution resumes when a
single keyboard key is pressed.
• : label
Any line in the batch file that starts with a colon
( : ) is considered a label 标签.Labels are used
by certain flow control commands to repeat or
skip over certain lines in the file.
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4.3.2 Batch File Commands
• goto label
This command causes the command processor
to execute the first command line after the label
referenced by the command.
• if exist filename command
If the statement is true, then the command is
executed. E.g.: if exist index.html del
index.html
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4.3.3 Lab: Creating a Batch File
• Example of a Batch File
• Example of a Batch File with Arguments
• Try to follow each example and determine
what actions are being performed by the
commands in the batch file.
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Example of a Batch File
• Batch file: COPYWP.BAT
REM Batch file created by John Smith
@ ECHO OFF
ECHO Copying Word and PPT files to a floppy
:LOOP
ECHO Please insert a floppy into drive A:
PAUSE
COPY C:\data\smith\*.doc a:\
COPY C:\data\smith\*.ppt a:\
GOTO LOOP
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Example of a Batch File with
Arguments
• Batch file: COPYWP.BAT
REM Batch file created by John Smith
@ ECHO OFF
ECHO Copying Word and PPT files
:LOOP
ECHO Please insert floppy into drive A:
PAUSE
COPY C:\data\%1\*.doc a:\
COPY C:\data\%1\*.ppt a:\
GOTO LOOP
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Example of a Batch File with
Arguments
• Batch file: COPYWP.BAT
REM Batch file created by John Smith
@ ECHO OFF
ECHO Copying files
:LOOP
ECHO Please insert floppy into drive A:
PAUSE
COPY C:\data\%1\*.%2 a:\
GOTO LOOP
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4.4 Databases
• Databases are one of the most common
business applications of computers
• Example: Every company has an
employee database for keeping track of its
personnel, and schools have databases to
keep track of their students.
• Database , table , record , field , data type
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4.4 Databases
Reading Sequence:
• Parsons/Oja, Database Software in Section 3C.
Page 174-176
Learning Goal: Knowledge of the components of a
database: fields, records, files and database management
software.
In Addition: After completing this reading, go to the online
phone directory people.yahoo.com and look up the phone
number of someone you know. Based on the listing you get
back, what fields do you think are present in the database?
Assessments:
• Multiple-Choice Quiz 15
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Data management software
• What is data management software?
• Data management software helps you to
store, find, organize, update, and report
information. Several types of data
management software exist, including file
management software and database
management software.
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File Management Software
• File: 1. a named collection of data that is stored
on some storage medium.
• 2. a structured file, a collection of records, each
with the same set of fields that can hold data.
• Each record记录 holds data for a single entity
实体—a person, place, thing or event. A field
字段 holds one item of data relevant 相应的 to a
record, contains the smallest unit of meaningful
data in a data file.
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Basic Concepts
• Data(数据)
• Database(数据库)
• DBMS(数据库管理系统)
• DBS(数据库系统)
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SQL
• Structured Query Language (SQL) is a popular
query language used by numerous data
management software packages.
• SQL语言的动词
SQL功能
数据定义
数据查询
数据操纵
数据控制
动词
CREATE,DROP,ALTER
SELECT
INSERT,UPDATE,DELETE
GRANT,REVOKE
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SQL Example
[例1] 查询全体学生的学号与姓名。
SELECT Sno，Sname
FROM Student；
[例2] 查询全体学生的姓名、学号、所在系。
SELECT Sname，Sno，Sdept
FROM Student；
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SQL Example
[例3] 查询全体学生的详细记录。
SELECT Sno ， Sname ， Ssex ， Sage ，
Sdept
FROM Student；
或
SELECT *
FROM Student；
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SQL Example
[例4] 查全体学生的姓名及其出生年份。
SELECT Sname，2007-Sage
FROM Student；
输出结果：
Sname 2007-Sage
--------- ------------李勇 1976
刘晨 1977
王名 1978
张立 1978
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4.5 Software Engineering
4.5.1 Issues in Large-Scale Software Development
• The Software Development Process
1.Define or redefine the problem.
2.Plan a solution to the problem.
3.Code the solution.
4.Evaluate and test everything.
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• In very large systems, such as the software
that controls a major e-commerce Web site,
there may be hundreds of people working
together to create the desired software
system. As the size of the development
team increases, the need for a shared
understanding of the goals for the system
becomes increasingly important.
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• Define or Redefine the Problem
– 对需求的共识
– 形成规范的文档
– 可能需要一个反复的过程
• Plan a Solution to the Problem
– 列举可能的解决方案
– 设计系统方案，并进行测试验证
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• Code the Solution
– Programmers code a system in the chosen
language or languages
– Programmer testing of solution
– System acceptance
• Evaluate and Test Everything
– 性能评估
– 功能测试
– 如需要，重新设计与处理
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4.5 Software Engineering
4.5.2 Open Source Model
• Unless you work for Microsoft, you will not
be allowed to read the source code for the
Windows operating system. But, you can
read the source code for the Linux
operating system, make copies of it, even
give it away for free. Linux is an example
of an open source software project.
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• Enjoy programming and have a need for
that particular piece of software, so it is in
their interest to help improve it by adding
new features or fixing bugs.
• It is still possible to make money with open
source software, by selling support services,
printed manuals, or proprietary add-ons that
enhance an open source product
• Free Software , the software is protected by
a license
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Open Source Model
• Open source advocates argue that when
code is available for anyone to read, "All
bugs are shallow," meaning they will be
tracked down quickly by somebody.
• In addition, some users place a greater
degree of trust in open-source systems
because it is harder to hide malicious
features, such as built-in security holes or
mechanisms that violate privacy.
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Open Source Model
• Most software today is still produced using a
closed-source model. Companies must invest
substantial funds to create a successful software
product. Giving the code away would rob them
of the chance to recoup those costs through
sales. The code may also contain what a
company regards as proprietary technology, or
trade secrets, such as tricks for improving the
performance of a database system, that it does
not want to reveal to competitors.
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Open Source Model
• It is still possible to make money with open
source software, by selling support services,
printed manuals, or proprietary add-ons that
enhance an open source product. Several
companies now market Linux distributions this
way. Another famous open source software
system is the Netscape browser. Originally
developed as a closed source product,
Netscape decided to turn the browser into an
open source system and give it away for free.
The company makes money by selling server
software and other services.
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Software License
• Free software自由软件 may be used for any
purpose, copied, modified, and redistributed at
will. In order to ensure that these freedoms are
preserved in all copies and derivative versions,
the software is protected by a license. A variety
of free software licenses have been proposed.
One is called copyleft, a pun on "copyright."
– GPL license ( GNU General Public License)
– BSD license ( Berkeley Software Distribution license,)
• Shareware
• Public Domain Software
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4.5 Software Engineering
4.5.3 Tools for Software Creation and Management
• Editors
– 纯文本的编辑
– 支持对特定语言格式的识别和语法检查
• Compilers
– Compilers take program source code written by
people as input and produce object code
suitable for machine execution
– 语法错误的识别和错误报告
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• Debuggers
– The most popular of debugging tools are the
visual debuggers, which provide a graphical
representation of the program's execution
• Integrated Development Environments
(IDEs)
– IDEs have become increasingly popular
– IDEs like Microsoft Visual Studio, IBM Visual
Age, and Symantec Cafe are software suites
consisting of editors, compilers, debuggers, and
software engineering tools for program
documentation and maintenance.
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Exercise 4
• Question 1. DOS Commands
• In this section, you will interface with the
operating system using DOS commands.
For each of the following tasks, list the correct
DOS command. Note: While it is not necessary
to perform these tasks on a computer, the
assignment is structured for each task to be
completed in sequence; that is to say, a task
may depend on the state created by previous
tasks.
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• Display the syntax and switches for the command dir.
• List all directories and files in C:\, pausing if the
information scrolls off the display.
• List all directories and files in C:\ with a three-character
file name beginning with W.
• List all files in C:\ whose extension contains X and sort
the results by size.
• List all directories and files in C:\, redirecting the output
to a file named "ssd2.txt" in directory C:\.
• List all directories and files in C:\, appending the output
to ssd2.txt.
• In directory C:\, create a subdirectory called "SSD2".
• Copy ssd2.txt to directory SSD2.
• Rename ssd2.txt in directory SSD2 as "ssd2.bak".
• Delete ssd2.txt.
• Remove directory SSD2.
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Exercise 4
• Question 2. Batch File Creation
• In this section, you will interface with the
operating system using DOS commands.
For each of the following tasks, list the correct
DOS command. Note: While it is not necessary
to perform these tasks on a computer, the
assignment is structured for each task to be
completed in sequence; that is to say, a task
may depend on the state created by previous
tasks.
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Exercise 4
• Name the batch file EXDIR.BAT.
• Include your name as a remark in EXDIR.BAT.
• Include the creation date as a remark in
EXDIR.BAT.
• Include the function of EXDIR.BAT as a remark
in EXDIR.BAT- redirects the output of dir C:\ to a
file named by the user.
• The filename provided by the user is the first
argument.
•
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Exercise 4
• A valid switch for the command dir is the optional
second argument.
• If the file named by the user already exists,
EXDIR.BAT immediately generates an error
message and then exits without executing dir.
• The error message generated by EXDIR.BAT
must display, "filename already exists, aborting
EXDIR."
• Please upload and submit your batch file
(EXDIR.BAT) when you are done.
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Exercise 4
•
•
•
•
•
Question 3. Database Specification
Consider creating a database on an e-commerce Web
server.
The three tables in the database are Customer
Information, Supplier Information, and Warehouse
Information. For each table, do the following:
List the fields required to capture all of the information
necessary and their corresponding data types. Your
answer should be in the following format:
[table name]
[field name]: [data type]
Possible data types for the fields are Text, Numeric,
Integer, Date, and Currency.
Indicate which of the fields in a table is the primary key
for the table.
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