[Book Guide] Easy Programming CGI/Perl by Yuki Kimoto

Perl
Book Guide

This is the CGI/Perl version of the book released as the "Easy Programming" series by Gijutsu-Hyoronsha.

[asin: 4774139289:detail]

This book seems to be the only CGI book written in modern Perl at this time. Most Perl books about CGI contain a lot of less recommended descriptions from the time Perl 4 was all the rage.

It seems unlikely that CGI books are written with modern Perl in mind.

The explanation of CGI is not about the details of the protocol, but it is an explanation that makes it easy to imagine what will be done internally when developing a Web application using the CGI protocol. ..

The explanation is such that you can understand the flow of "browser->HTTP request issuance->web server->CGI script->HTTP response generation->web server->browser".

CGI itself is no longer mainstream because it's slow, but I think it's useful as a help in understanding how web applications work.

It also explains in detail the part where CGI is placed and actually executed on Sakura's rental server. The explanations such as FFFTP are also polite, and when actually deploying CGI on the server, consideration is given to avoid tripping as much as possible.

This book contains a pure "Introduction to Perl" with rounded chapters. This chapter has nothing to do with CGI scripts, so you can read it as an introduction to modern Perl. The second chapter of Perl, which is useful for business, explains the basics of Perl, but I think it would be easier to imagine if you think that this is explained carefully.

Also, download the example code used in this manual from the Web. You can also try it.

Since this is my first work, there are quite a few typos and many typographical errors.

Challenge the web framework

The technique of writing web applications with CGI scripts is now obsolete. Let's challenge a web application using a web framework.

Easy programming I rewrote the web application example published in CGI/Perl with a framework called Mojolicious.

Easy programming CGI/Perl errata

We have created an errata for "Easy Programming CGI/Perl". It describes what you discovered and what you were told. It contains a lot of mistakes. I think most of the example code works.

page	place	Wrong	Positive
P18	Lower row	UTF-8 is changed to utf-8 in the explanation of Accept-Charset	UTF-8 is correct
P24	Middle row	"The data of the message body sent by the POST method is ..." is entered in duplicate.	Remove duplication
P31	Upper row	By default, "I Accept…" is checked.	By default, "I Accespt…" is not checked
P34	Upper row	Web applications are composed of four elements, "HTML", "HTTP", "CGI", and "Perl", and knowledge of each is indispensable.	Web applications are made up of multiple technologies that require you to learn about "HTML, " "HTTP, " "CGI, " and "Perl."
P34	Middle row	HTTP is not written like a CGI script, but the information described can be used in the script.	The HTTP request header information can be used in the CGI script.
P34	Lower row	The method of passing data from the web server to the CGI script is called "standard input", and the method of passing data from the CGI script to the web server is called "standard output".	Use "standard input" to pass data from the web server to the CGI script, and use "standard output" to pass data from the CGI script to the web server.
P59	Middle row	The position of "8. The description of Perl execution path is incorrect" is different.	The position immediately after "7. CGI script permissions" on page 056 is correct.
P62	Upper row	Display on screen	Display on screen
P64	Middle row	Includes Unix extended OS and Linux OS	Includes Unix-extended OS and Linux-based OS
P74	Upper row	Unlike the inequality sign, "=" does not mean "equal to".	Unlike the equal sign in mathematics, "=" does not mean "equal to".
P75	Upper row	Use a name that makes sense.	Use a name that makes sense.
P79	Lower row	There is a weird sign called l <	Forgotten to delete
P83	Middle row	The position of "You can access the elements of the array using subscripts." Is incorrect.	Immediately after "Array elements" in the middle heading is correct.
P84	Middle row	Assigning an a array variable to a scalar variable in this way is called a scalar context.	This sentence is correct to remove because the description is incorrect.
P86	Middle row	Middle heading "Add an array to an array"	"Add multiple elements to the array" is correct
P86	Middle row	It supports not only one element but also the addition of arrays	It supports not only one element but also multiple elements
P87	Middle row	Source code @nums = reverse sort {$b <=> $a} @nums	I don't need reverse. @nums = sort {$b <=> $a} @nums is correct.
P88	Middle row	Source code ($name, $age) = ('Ken', 'Taro')	($name, $age) = ('Ken', 18) is correct
P85	Upper row	There is no closing brace in the if part of the source code	Add closing brace
P86	Lower row	This is an example of extracting the first and second elements of an array.	This is an example of extracting two elements from the second element of the array (1 with a subscript).
P87	Upper row	This is an example of replacing two elements from the first position of an element in the array.	This is an example of replacing two elements from the second element of the array (1 with a subscript).
P89	Lower row	"Print $animal_join;" is missing at the end of the source code	Added print $animal_join;
P089	Lower row	I'm using join even though I haven't explained about join.	It is explained in Chapter 3, Section 5, "Numerical Arithmetic and String Manipulation".
P89	Middle row	Source code line 18 my $last_animals = pos;	my $last_animals = pop @animals is correct
P102	Upper row	Returns the character number from which the position starts	Returns that position as a return value
P091	Lower row	After international standard	International standard language
P105	Lower row	There is garbage called> ll.	It is correct to remove.
P108	14th line from the top	Logical sum (what and what)	OR (what or what)
P110	Lower row	How to execute the script is missing	Let's run the script with arguments. It is correct to add perl example_3_6 1 2
P111	7th line from the top	"0" is in the first element	"1" is the first element
P111	3rd line from the bottom	$num[0] $num[1]	$nums[0] $nums[1]
P114	Lower row	If "$animal" is "cat"	If "$animal" is "dog"
P123	Upper row	samplw_3_8.pl	example_3_8.pl
P145	Upper row	close $fh	close $fh;
P148	Upper row	It's a little advanced topic, but you should definitely know it.	It's a little advanced topic, but there are some things you should know.
P157	Middle row	windwos perl nmake	windows perl nmake
P158	Middle row	Let's make it complete	Let's keep it concise
P158	Upper row	Perl scripts are run from Perl commands, specifying the directory where the script resides from a command prompt or shell, not from a web browser.	Perl scripts are executed using perl commands from a command prompt, shell, etc.
P158	Upper row	A variable is a mechanism that can store a value. The value can be maintained until the program ends and can be used repeatedly.	It is correct to modify it to "Variable can be assigned values." Variable don't hold their value until the end of the program.
P162	Middle row	There is no slash (/) in the closing tag of the title tag.	It is correct to have a slash.
P164	Middle row	There is no slash (/) in the closing tag of the title tag.	It is correct to have a slash.
P165	Middle row	There is no slash (/) in the closing tag of the title tag.	It is correct to have a slash.
P167	Middle row	There is no slash (/) in the closing tag of the title tag.	It is correct to have a slash.
P170	Middle row	There is no slash (/) in the closing tag of the title tag.	It is correct to have a slash.
P173	Middle row	The URL of the action of the form is specified incorrectly.	/cgi-bin/simple-form.cgi is correct.
P174	Upper row	/var/www/htm	/var/www/html
P176	Lower row	The received string was output.	The received string is output.
P207	Upper row	No source code name	image-bbs.cgi
P232	Upper row	The heading "The data to be output is always ..." is the middle heading.	The subheading is correct
P234	Upper row	Is there a module that plays the role of the executed program?	Is there a module that plays the role of the program you want to execute?
P235	Lower row	Embed tara in the source code?	"Embed taro in the? Part" is correct.

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