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CGI Architecture Diagram Web Server Support & Configuration Before you proceed with CGI Programming, make sure that your Web Server supports CGI and it is configured tohandle CGI Programs. All the CGI Programs to be executed by the HTTP server are kept in a pre-configureddirectory. This directory is called CGI Directory and by convention it is named as /var/www/cgi-bin. By convention,CGI files will have extention as .cgi,ss but you can keep your files with python extension .py as well.By default, the Linux server is configured to run only the scripts in the cgi-bin directory in /var/www. If you want tospecify any other directory to run your CGI scripts, comment the following lines in the httpd.conf file:<Directory "/var/www/cgi-bin">AllowOverride NoneOptions ExecCGIOrder allow,denyAllow from all</Directory><Directory "/var/www/cgi-bin">Options All</Directory>Here, I assumed that you have Web Server up and running successfully and you are able to run any other CGIprogram like Perl or Shell, etc.First CGI Program Here is a simple link, which is linked to a CGI script called hello.py. This file is being kept in /var/www/cgi-bindirectory and it has following content. Before running your CGI program, make sure you have change mode of fileusing chmod 755 hello.py UNIX command to make file executable.#!/usr/bin/pythonprint "Content-type:text/html\r\n\r\n"print '<html>'print '<head>'print '<title>Hello Word - First CGI Program</title>'print '</head>'print '<body>'print '<h2>Hello Word! This is my first CGI program</h2>'print '</body>'print '</html>'TUTORIALS POINT Simply Easy Learning
If you click hello.py, then this produces the following output:Content-type:text/htmlHello Word! This is my first CGI programThis hello.py script is a simple Python script, which is writing its output on STDOUT file i.e., screen. There is oneimportant and extra feature available which is first line to be printed Content-type:text/html\r\n\r\n. This line issent back to the browser and specify the content type to be displayed on the browser screen.Now, you must have understood basic concept of CGI and you can write many complicated CGI programs usingPython. This script can interact with any other exertnal system also to exchange information such as RDBMS.HTTP Header The line Content-type:text/html\r\n\r\n is part of HTTP header which is sent to the browser to understand thecontent. All the HTTP header will be in the following form:HTTP Field Name: Field ContentFor ExampleContent-type: text/html\r\n\r\nThere are few other important HTTP headers, which you will use frequently in your CGI Programming.HeaderContent-type:Expires: DateLocation: URLLast-modified: DateContent-length: NDescriptionA MIME string defining the format of the file being returned. Example is Contenttype:text/htmlThe date the information becomes invalid. This should be used by the browser todecide when a page needs to be refreshed. A valid date string should be in theformat 01 Jan 1998 12:00:00 GMT.The URL that should be returned instead of the URL requested. You can use thisfield to redirect a request to any HTML file.The date of last modification of the resource.The length, in bytes, of the data being returned. The browser uses this value toreport the estimated download time for a file.Set-Cookie: StringCGI Environment Variables Set the cookie passed through the stringAll the CGI program will have access to the following environment variables. These variables play an importantrole while writing any CGI program.Variable NameCONTENT_TYPECONTENT_LENGTHHTTP_COOKIEDescriptionThe data type of the content. Used when the client is sending attached content tothe server. For example, file upload, etc.The length of the query information. It's available only for POST requests.Returns the set cookies in the form of key & value pair.TUTORIALS POINT Simply Easy Learning
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Python Tutorial
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ABOUT THE TUTORIALPython TutorialPy
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Description .......................
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Parameters ........................
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Locating Modules: .................
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Description .......................
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Return Value ......................
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Example ...........................
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Parameters ........................
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Regular-expression Modifiers - Opti
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Starting a New Thread: ............
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Example: ..........................
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CHAPTER1Python OverviewPython is a
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CHAPTER2Python EnvironmentBefore we
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• To use this installer python-XY
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-c cmd run Python script sent in as
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This will produce the following res
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file_name = raw_input("Enter filena
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$ python -husage: python [option] .
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print 'Input file is "', inputfilep
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Here, an integer object is created
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Python Lists: Lists are the most v
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FunctionDescriptionint(x [,base])Co
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CHAPTER5Python Basic OperatorsWhat
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Line 4 - Value of c is 2Line 5 - Va
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Line 5 - a is greater than bLine 6
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| Binary OR Operator copies a bit i
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else:print "Line 3 - a and b are tr
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if ( id(a) == id(b) ):print "Line 2
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When you execute the above program,
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if statementsif...else statementsne
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Example: #!/usr/bin/pythonvar1 = 10
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else:print "Could not find true exp
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Loop Typewhile loopfor loopDescript
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num = raw_input("Enter a number :")
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Good bye!Iterating by Sequence I
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11 is prime13 is prime17 is prime19
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continue statement The continue st
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CHAPTER8Python NumbersNumber data t
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max(x1, x2,...)min(x1, x2,...)modf(
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Syntax Following is the syntax for
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import math# This will import math
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import mathmath.log10( x )Note: Thi
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modf(x) Description The method modf
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round( x [, n] )Parameters • x --
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Return Value This method returns a
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seed([x]) Description The method se
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asin(x)Note: This function is not a
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print "atan2(-10,10) : ", math.atan
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Note: This function is not accessib
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import mathprint "degrees(3) : ", m
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CHAPTER9Python StringsStrings are a
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+ Concatenation - Adds values on ei
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TAB ( \t ) and they will show up th
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str = "this is string example....wo
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Return Value This method returns a
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Description The method expandtabs()
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Traceback (most recent call last):F
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Let us compile and run the above pr
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str = "This is string example....wo
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str = "-";seq = ("a", "b", "c"); #
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lstrip() Description The method lst
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Max character: xmin(str) Descriptio
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str = "this is really a string exam
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Parameters • chars -- You can sup
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Parameters• str -- This is the st
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Parameters • NAReturn Value This
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Example The following example shows
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CHAPTER10Python ListsThe most basic
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Python Expression Results Descripti
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list( seq )Parameters • seq -- Th
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Return Value If elements are of th
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list.insert(index, obj)Parameters
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CHAPTER11Python TuplesAtuple is a s
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len((1, 2, 3)) 3 Length(1, 2, 3) +
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-11-1len(tuple) Description The met
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min value element : 200tuple(seq) D
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#!/usr/bin/pythondict = {'Name': 'Z
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34str(dict)Produces a printable str
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type(variable) Description The meth
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Return Value This method does not
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CHAPTER13Python Date & TimeApython
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#!/usr/bin/pythonimport time;localt
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import timeprint "time.altzone %d "
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Parameters • sec -- These are the
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• %w - day of the week as a decim
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time.time( ) Description The metho
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2time.tznameAttribute time.tzname i
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CHAPTER14Python FunctionAfunction i
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#!/usr/bin/python# Function definit
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return;# Now you can call printinfo
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Inside the function : 30Outside the
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A module is loaded only once, regar
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'sqrt', 'tan', 'tanh']Here, the spe
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CHAPTER16Python Files I/OThis chapt
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rb+WWbw+wb+AAba+ab+Opens a file for
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fo.write( "Python is a great langua
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EXAMPLE: Following is the example t
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operations from the operating syste
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# Close opened filefo.close()Let us
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Parameters • NAReturn Value This
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Parameters • offset -- This is th
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Parameters • size -- If this opti
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Description The method writelines()
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53545556575859606162os.symlink(src,
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Return Value This method does not
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• stat.S_IRGRP: Read by group.•
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os.chroot("/tmp/usr")print "Changed
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Parameters • fd -- This is the or
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import os, sys# First go to the "/v
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Description The method fchown() cha
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Description The method fdopen() ret
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{'PC_MAX_INPUT': 2, 'PC_VDISABLE':
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# Open a filefd = os.open( "foo.txt
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print "Current working dir : %s" %
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path = "/var/www/html/foo.txt"fd =
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_vti_txtrobots.txtitemlistingresume
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# Close opened fileos.close( fd )#
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dev_num = os.makedev(major_dnum, mi
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Page 283 and 284: Description The method popen() open
Page 285 and 286: # !/usr/bin/pythonimport ossrc = '/
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Page 293 and 294: Description The method tcgetpgrp()
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Page 345 and 346: DELETE Operation: DELETE operation
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Page 353 and 354: Subject: SMTP e-mail testThis is a
Page 355 and 356: try:smtpObj = smtplib.SMTP('localho
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Page 367 and 368: Format: DVDRating: PGDescription: T
Page 369 and 370: Tkinter Widgets Tkinter provides v
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E1 = Entry(top, bd =5)E1.pack(side
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Optionanchorbgbitmapbdcursorfontfgh
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selectmodeDetermines how many items
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Syntax: Here is the simple syntax t
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Menu The goal of this widget is to
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filemenu.add_command(label="Exit",
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Example: Try the following example
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WidthWraplengthWidth of the label i
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label appears in the top left corne
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Parameters: • master: This repres
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Parameters: • master: This repres
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mark_gravity(mark [,gravity])Return
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Methods & Descriptiondeiconify()Dis
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disabledbackgrounddisabledforegroun
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bgbdThe color of the slider and arr
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fontheightlabelAnchorhighlightbackg
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Standard attributes:Let's take a l
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• family: The font family name as
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B2.pack()B3.pack()B4.pack()B5.pack(
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• "heart"• "heart"• "man"•
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The grid() Method This geometry m
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CHAPTERPython Further Extensions27A
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This table needs to be terminated w
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Passing Function Parameters: Beca
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return (a + b)You can return two va
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CHAPTER28Python Tools/UtilitiesThe
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The profile Module: The profile m
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