Transcript Perl - 成功大學myweb個人網頁空間服務說明

生物資訊程式語言應用
Part 3
Perl Language
Outline
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Introduction.
Installation.
Background knowledge in Perl.
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Data type.
Control structure.
Regular expression.
Overall practice.
Introduction
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Perl is free software.
Larry Wall (He is a linguist).
The history of Perl language.
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1987- Perl 1.0.
1994 - Perl 5 (contain OOP).
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OOP (object oriented programming) 物件導向程式語言
Perl 5.8.0 – support unicode.
2003 – Perl 6.
Now.
Characteristic.
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The script language base on C language (具跨平台的特性).
Installation
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Perl is the default language in any distribution of Linux.
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Perl can be executed and worked by the ActivePerl
package in windows platform.
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http://www.activestate.com/activeperl/
How to edit Perl program?
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Notepad in windows, UltraEdit and any text editor.
Installation
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cont.
Practice.
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Download ActivePerl software file.
Install ActivePerl.
Background knowledge
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Data type in Perl.
Control structure in Perl.
Regular expression in Perl.
Data type in Perl
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Like English
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Scalar (純量變數) – 比喻單件事物.
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數字常數 $x = 5;
字串常數 $y = “Hello” ;
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The special expression of Perl.
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Print “Hello” . ”World” ; (Hello World).
Print “Hello” * 2 ; (HelloHello).
字串與數字間的轉換
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$x = 123; $y = “456”;
Print $x + $y ; (數字)
Print $x . $y ; (字串)
Data type in Perl
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Practice.
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Using scalar.
Special expression.
字串與數字間的轉換.
cont.
Data type in Perl
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cont.
Array (陣列).
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The definition of Array in Perl.
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@student=("9154610","9154611",”9154612”);
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my @student;
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$student[0] ="9154610“; $student[1] =“9154611“; $student[2] =“9154611”;
Array 單數的取用.
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print $student[0],"\n";
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print "$student[1]\n";
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print $student[2]."\n";
Array 複數的取用.
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print @student,“\n”; (全部一起print出來)
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以單數取用方式print出複數資料 (in control structure chapter).
Data type in Perl
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Practice.
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Using array (definition).
單數取用.
複數取用.
cont.
Data type in Perl
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cont.
Hash (雜湊).
 $純量 = 單一 = 單數
 @陣列 = 串列 = 複數
 %雜湊 = 串列 = 複數
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定義陣列 = 類似ip
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@student=("9154610","9154611",”9154612”);
定義雜湊 = 類似dns
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%students = ("Peter"=>"9154610" , "Mary"=>"9154611" ,
"Cathy"=>"9154612");
Data type in Perl
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cont.
Hash (雜湊).
 定義雜湊 = 類似dns
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Hash 單數的取用.
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%students = ("Peter"=>"9154610" , "Mary"=>"9154611" ,
"Cathy"=>"9154612");
print $students{"Peter"},"\n";
print $students{"Mary"},"\n";
print $students{"Cathy"},"\n";
Hash 複數的取用.
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print %students,"\n";
以單數取用方式print出複數資料 (in control structure chapter).
Data type in Perl
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Practice.
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Using hash (definition).
單數取用.
複數取用.
cont.
Control structure in Perl
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If statement (陳述式).
For loop (迴圏).
Foreach loop (迴圏).
While loop (迴圏).
Control structure in Perl
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cont.
If statement (陳述式).
If 條件判斷
If 條件成立則執行
若If 條件不成立則執行
(else statement可有可無)
Control structure in Perl
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Practice.
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If statement.
If - else statement.
cont.
Control structure in Perl
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cont.
For loop (迴圏).
$#array : 取得array的大小
$i++ : 等同於 $i = $i + 1;
$sum += $i : 等同於 $sum = $sum + $i;
Control structure in Perl
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cont.
Practice.
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For loop 迴圏.
以array單數取用方式print出array複數資料.
以hash單數取用方式print出hash複數資料.
Control structure in Perl
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cont.
Foreach loop (迴圏).
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Like for loop.
For loop
Foreach loop
Control structure in Perl
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cont.
Practice.
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Foreach loop (迴圏).
以array單數取用方式print出array複數資料.
以hash單數取用方式print出hash複數資料.
Control structure in Perl
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cont.
While loop (迴圏).
While 判斷式
Control structure in Perl
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Practice.
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While loop (迴圏).
1+2+…+100.
cont.
Regular expression in Perl
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樣式 (pattern) 的表達.
 繫結符號 =~.
 =~可用來將右邊的樣式比對左邊的字串純量，成功
傳回1，失敗傳回0.
 表否定則可改用!~
 通常搭配判斷式使用.
Regular expression in Perl
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比對.
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$` : 代表字串中比對成功之前的部分.
$& : 代表字串中比對成功的部分.
$‘ : 代表字串中比對成功之後的部分.
cont.
Regular expression in Perl
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字元取代.
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cont.
$var =~ tr/xxx/yyy/
把變數 $var 內的 xxx 字元都逐一代換成 yyy 字元
字串取代.
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$var =~ s/xxx/yyy/
把變數 $var 內的第一個 xxx 子字串整個代換成 yyy 子字串
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$var =~ s/xxx/yyy/ig
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I : 忽略大小寫
g : 取代 $var 字串內所有符合的子字串
Regular expression in Perl
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Practice.
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比對.
字元取代.
字串取代.
cont.