perl

perl

Turning on cgi processing in apache • Cgi processing cabability is available in the apache server but needs to be turned on by editing config files. • Cgi processing handles requests to the server that have url: http://TheUrl/cgi-bin/…

Turning on cgi processing in apache • Useful link: http://www.ricocheting.com/server/cgi.html • Activating CGI • Using Notepad (or other text editor) open E:\Apache2\conf\httpd.conf (also should be start-menu shortcut called "Edit Apache HTTP httpd.conf File") and search for Options Indexes FollowSymLinks (about line 267) when you find it add ExecCGI to the end so it looks like Options Indexes FollowSymLinks ExecCGI

Turning on cgi processing in apache • Enabling CGI in any directory [optional] • If you want to use CGI outside ScriptAliased directory (ScriptAlias is usually the Apache2/cgi-bin/), you will need to uncomment the following line: #AddHandler cgi-script .cgi • becomes AddHandler cgi-script .cgi.pl .rb • (remove the #) I also added .pl behind .cgi so files with the 'perl' extension are also treated as cgi files.We’ll later use ruby, too so you might as well add rb extensions to the list.You might also want to comment out: ScriptAlias /cgi-bin/ "E:/Apache2/cgi-bin/" • so it becomes #ScriptAlias /cgi-bin/ "E:/Apache2/cgi-bin/"

Another useful page • http://www.thesitewizard.com/archive/addcgitoapache.shtml • There are just a few changes to make: • To find perl scripts in cgi-bin directory (fix path, too): • ScriptAlias /cgi-bin/ "C:/Program Files/Apache Group/Apache/cgi-bin/" • To allow both pl and cgi suffix: • AddHandler cgi-script .cgi .pl .rb • <Directory /> Options FollowSymLinks AllowOverride None</Directory> • Change options to: • Options FollowSymLinks +ExecCGI

On my apache version: about line 187 of the httpdconf file <Directory /> Options FollowSymLinks ExecCGI Includes AllowOverride None Order deny,allow Deny from all </Directory>

Turn on cgi • Enabling SSI [optional] • Find the line from Step 1: Activating CGI and add Includes to the end so it becomes Options Indexes FollowSymLinks ExecCGI IncludesFind and uncomment the following lines #AddType text/html .shtml and #AddOutputFilter INCLUDES .shtml (Search for them, then remove the #)Some notes If you don't know what SSI (Server Side Include) is, I suggest looking for more info about it. It is a huge time saver for updating pages (you can update one "menu file" and have hundreds of pages reflect the updated changes). However, it adds additional strain on a server and can potentially make a server slightly less secure, so if you are not using, do not enable it.Since I use SSI for everything, I changed the settings so *.html files can also run SSI (by default it's only .shtml). So I have AddOutputFilter INCLUDES .shtml .htmlAddOutputFilter is completely different than the AddHandler server-parsed way Apache 1.3.x handled it. • Finding your location to perl • If you do not know where your perl.exe installed to, go to Start -> Search and type in a search for perl.exe This location is the path to perl you put on the top of all your cgi scripts. If you listened to my advice in the "Install" step, the path should be close to: E:/usr/bin/perl

Turning on cgi (unix) • Some notes For the perl path E:/usr/bin/perl.exe all of these are/were valid. I prefer the last one, but to each their own.#!E:/usr/bin/perl.exe#!E:/usr/bin/perl#!/usr/bin/perl.exe#!/usr/bin/perl • Note: for us this path will be something like • #!P:\perl\perl.exe • Testing CGIIf you did not disable ScriptAlias /cgi-bin/ then create a file in E:/Apache2/cgi-bin/ called hello.cgi and put these three lines in it (if you did disable it, put the CGI file anywhere in your document_root):#!/usr/bin/perl print "Content-type:text/html\n\n"; print "hello world"; • Restart Apache if it is already running. Now go to http://127.0.0.1/cgi-bin/hello.cgi or localhost and run this script. (scripts in Apache2/cgi-bin/ are read as http://127.0.0.1/cgi-bin/ by default, although if did step (2) you should be able to run CGI scripts from anywhere). • If you get a hello world in your browser, CGI is running. If you get a 500 error, go to the last entry in E:/Apache2/logs/error.log (or the Review Error Log in the start menu) to see exactly what caused this error.

Port number 80 or 8080(line 53 in my httpd.conf) # Listen: Allows you to bind Apache to specific IP addresses and/or # ports, instead of the default. See also the <VirtualHost> # directive. # # Change this to Listen on specific IP addresses as shown below to # prevent Apache from glomming onto all bound IP addresses (0.0.0.0) # #Listen 12.34.56.78:80 Listen 80

Addhandler (line 418) • add .pl to this line: AddHandler cgi-script .cgi .pl

Some perl program examples • Perl programs will need their first line to include the path to the perl compiler. This line starts with #! (called shebang) #!c:\perl\bin\perl.exe Perl statements end in a semi-colon

Hello world: note shebang 1st line points to perl on system #!c:\perl\bin\perl.exe print "Content-type:text/html\n\n"; print "hello world";

Deploying the helloworld example:Drop perlscripts into cgi-bin

Using variables • Simple variables in perl start with a $: $mystring = "Hello, World"; $mypi = "3.14159"; Note, there is no difference between string, int and float value declaration or assignments.

Using variables #!c:\perl\bin\perl.exe print "Content-type: text/html \n\n"; # the header $mystring = "Hello, World"; $myescapechar = "Welcome to Joe\'s"; $myinteger = "5"; $myinteger2 = "-5"; $mypi = "3.14159"; print $mystring; print " "; print $myescapechar; print " "; print $myinteger; print " "; print $myinteger2; print " "; print $mypi;

Vars.pl

Shortcut operators as in java or c++ #!c:\perl\bin\perl.exe print "content-type: text/html \n\n"; #The header $x = 14; $y = 10; $area = ($x * $y); print $area; print " "; $x += 4; #adds 4 to x $y += 12; #adds 12 to y $area = ($x * $y); print $area;

Running vars2

Strings #!c:\perl\bin\perl.exe print "content-type: text/html \n\n"; #The header $single = "This string is single quoted"; $double = 'This string is double quoted'; $userdefined = q^Carrot is now our quote^; print $single; print " "; print $double; print " "; print $userdefined;

Running it

substrings #!c:\perl\bin\perl.exe print "content-type: text/html \n\n"; #The header $mystring = "Welcome to higgins perl examples!"; $twoarguments = substr($mystring, 11); $threearguments = substr($mystring, 8, 2); print $twoarguments; print " "; print $threearguments;

More substrings #!c:\perl\bin\perl.exe print "content-type: text/html \n\n"; #The header $mystring = "Welcome to www.anywhere.com!"; print $mystring; print ""; substr($mystring, 11) = "www.google.com!"; print $mystring;

Escape char to print $ and @ #!c:\perl\bin\perl.exe #since $ is used to define a var and @ defines an array #we need to use escape chars to put these in our output print "Content-type: text/html \n\n"; # the header $string = "David paid \$4.34 for Larry\'s shirt."; $email = "youremail\@youremail.com"; print "$string "; print "$email "; print '$string and $email';

Running escape.pl

Substrings continued

substrings

Interpolation: interpreting variables and instructions #!c:\perl\bin\perl.exe print "Content-type:text/html\n\n"; $a = 'apples'; $b = 'pears'; print "$a and $b";

From the previous example $a = 'apples'; $b = 'pears'; print "$a and $b"; • In the previous example, note that perl “interpreted” variable references even though they were inside the quotes and replaced the $a and $b by their values.

Fibonacci numbers $old=$next=1; print "$next \n"; while($old<1000){ $next+=$old; $old=$next-$old; print "$next \n"; } #print "$next \n";

Fib program C:\PERL\BIN>perl fib.pl 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584

Arrays in perl • Use @ to denote an array. Note recursive reference in the 2nd line below: @music = ("whistle", "flute"); @moremusic = ("organ", @music, "harp"); @food = ("apples", "pears", "eels");

Array example –some recursive assignments, push and pop, output #!c:\perl\bin\perl.exe print "Content-type:text/html\n\n"; @music = ("whistle", "flute"); @moremusic = ("organ", @music, "harp"); @food = ("apples", "pears", "eels"); push(@food, "eggs"); push(@food, ("eggs", "lard")); $grub = pop(@food); ($a, $b) = @food; print @food; # By itself print "@food"; # Embedded in double quotes print @food.""; # In a scalar context

Has output

A hash • A hash is a key-value pair structure • It is designated with a % symbol %coins = ( "Quarter" , '25',"Dime" , '10',"Nickel", '05', );

Hash “table” #!c:\perl\bin\perl.exe print "content-type: text/html \n\n"; #The header %coins = ( "Quarter" , '25',"Dime" , '10',"Nickel", '05', ); while (($key, $value) = each(%coins)){ print $key.", ".$value." "; } $coins{Penny} = "01"; $coins{HalfDollar} = "50"; print " "; while (($key, $value) = each(%coins)){ print $key.", ".$value." "; }

running

Running CGI…an html points to a cgi program <?xml version = "1.0" encoding = "utf-8"?> <!DOCTYPE html PUBLIC "-//w3c//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">  <html xmlns = "http://www.w3.org/1999/xhtml"> <head> <title> XHTML to call the Perl CGI program, reply.cgi </title> </head> <body> This is our first Perl CGI example <a href = "http://localhost/cgi-bin/reply.cgi"> Click here to run the CGI program, reply.cgi </a> </body> </html>

Reply.cgi in the cgi-bin directory #!c:\perl\bin\perl.exe # reply.cgi # This CGI program returns a greeting to the client print "Content-type: text/html \n\n", "<?xml version = '1.0' encoding = 'utf-8'?> \n", "<!DOCTYPE html PUBLIC '-//w3c//DTD XHTML 1.1//EN'\n", "'http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd'>\n", "<html xmlns = 'http://www.w3.org/1999/xhtml'>\n", "<head><title> reply.cgi example </title></head>\n", "<body>\n", "<h1> Greetings from your Web server! </h1>\n", "</body></html>";

The html

The reply

Popcorn.pl uses CGI module • Use ppm to install the CGI module: C:\PERL>ppm install CGI • (See screenshot in next slide)

ppm install CGI • C:\PERL>ppm install CGI • ==================== • Install 'CGI' version 2.91 in ActivePerl 5.8.7.815. • ==================== • Installing C:\Perl\html\site\lib\CGI.html • Installing C:\Perl\html\site\lib\CGI\Apache.html • Installing C:\Perl\html\site\lib\CGI\Carp.html • Installing C:\Perl\html\site\lib\CGI\Cookie.html • Installing C:\Perl\html\site\lib\CGI\Fast.html • Installing C:\Perl\html\site\lib\CGI\Pretty.html • Installing C:\Perl\html\site\lib\CGI\Push.html • Installing C:\Perl\html\site\lib\CGI\Switch.html • Installing C:\Perl\html\site\lib\CGI\Util.html • Installing C:\Perl\site\lib\CGI.pm • Installing C:\Perl\site\lib\CGI\Apache.pm • Installing C:\Perl\site\lib\CGI\Carp.pm • Installing C:\Perl\site\lib\CGI\Cookie.pm • Installing C:\Perl\site\lib\CGI\Fast.pm • Installing C:\Perl\site\lib\CGI\Pretty.pm • Installing C:\Perl\site\lib\CGI\Push.pm • Installing C:\Perl\site\lib\CGI\Switch.pm • Installing C:\Perl\site\lib\CGI\Util.pm • Successfully installed CGI version 2.91 in ActivePerl 5.8.7.815.

popcorn.pl uses CGI module #!c:\perl\bin\perl.exe #print "Content-type:text/html\n\n"; # popcorn.pl # A CGI program, written using CGI.pm, to process # the popcorn sales form # Initialize total price and total number of purchased items $total_price = 0; $total_items = 0; use CGI ":standard"; # First produce the header part of the HTML return value print header(); print start_html("CGI-Perl Popcorn Sales Form, using CGI.pm"); # Set local variables to the parameter values my($name, $street, $city, $payment) = (param("name"), param("street"), param("city"), param("payment")); my($unpop, $caramel, $caramelnut, $toffeynut) = (param("unpop"), param("caramel"), param("caramelnut"), param("toffeynut"));

popcorn.pl # Compute the number of items ordered and the total cost if ($unpop > 0) { $cost = 3.0 * $unpop; $total_price += $cost; $total_items += $unpop; } if ($caramel > 0) { $cost = 3.5 * $caramel; $total_price += $cost; $total_items += $caramel; } if ($caramelnut > 0) { $cost = 4.5 * $caramelnut; $total_price += $cost; $total_items += $caramelnut; } if ($toffeynut > 0) { $cost = 5.0 * $toffeynut; $total_price += $cost; $total_items += $toffeynut; } # Produce the result information to the browser and finish the page print "<h3>Customer:</h3>\n", "$name \n", "$street \n", "$city \n", "Payment method: $payment \n", "<h3>Items ordered:</h3> \n", "Unpopped popcorn: $unpop \n", "Caramel popcorn: $caramel \n", "Caramel nut popcorn: $caramelnut \n", "Toffey nut popcorn: $toffeynut \n", "You ordered $total_items popcorn items \n", "Your total bill is: \$ $total_price \n"; print end_html();

Html Form in htdocs takes an order

Script (in cgi-bin) processes it

Cookies: prints “first visit” or…

cookies1 #!c:\perl\bin\perl.exe # day_cookie.pl # - A CGI-Perl program to use a cookie to remember the # day of the last login from a user and display it when run use CGI ":standard"; # Get the existing day cookie, if there was one @last_day = cookie('last_time'); # Get the current date and make the new cookie $day_of_week = (qw(Sunday Monday Tuesday Wednesday Thursday Friday Saturday)) [(localtime)[6]]; $month = (qw(January February March April May June July August September October November December)) [(localtime)[4]]; $day_of_month = (localtime)[3]; @day_stuff = ($day_of_week, $day_of_month, $month); $day_cookie = cookie(-name => 'last_time', -value => \@day_stuff, -expires => '+5d');

cookies2 # Produce the return document # First, put the cookie in the new header print header(-cookie => $day_cookie); print start_html('This is day_cookie.pl'); # If there was no day cookie, this is the first visit if (scalar(@last_day) == 0) { print "Welcome to you on your first visit to our site "; } # Otherwise, welcome the user back and give the date of the # last visit else { ($day_of_week, $day_of_month, $month) = @last_day; print "Welcome back! ", "Your last visit was on ", "$day_of_week, $month $day_of_month "; } print end_html;

File i/o: processing a data file C:\PERL\BIN>perl wages.pl Names that end in 'son' Johanson Williamson Percent of employees under 40 is: 20 Average salary of employees under 40 is: 35000 There were no employees under 40 who earnedover ,000 C:\PERL\BIN>

perl

perl

Presentation Transcript

Perl

Perl

PERL

Perl

Perl

Perl

PERL

PERL

Perl

Perl

PERL

Perl

Perl

Perl

Perl

Perl

Perl