... Chapter 3: Learning HTTP- P3
HTTP Headers
Now we're ready for the meat of HTTP: the headers that clients and servers
can use to exchange information ... web client requests the document
without sending an Authorization header. If the server denies access to
the document, the server specifies the authorization method for the client to
use with ...
If-Modified-Sinc...
... from URL-encoded format to retrieve
the values entered by the user.
File uploads with POST
Chapter 3: Learning HTTP- P1
In the previous chapter, we went through a few examples of HTTP
transactions ... that it seemed best to present it this way.
Client Request Methods
A client request method is a "command" or "request" that a web client issues
to a se...
... data with
PUT.
In practice, a web server may request authorization from the client. Most
webmasters won't allow any arbitrary client to publish documents on the
server. When prompted with ... the
client may continue with its request.
101 Switching
Protocols:
The server is complying with a client request to switch
protocols to the one specified in the Upgrade head...
... not fully compliant with the HTTP specs, the web server won't
understand you! Perhaps your web client works with one web server but not
another. Or maybe your web client works most of ... character is '^'.
Tue Jun 14 00: 03:1 2 1996
Connection closed by foreign host.
Your First Web Client
Let's modify the previous code to work with a web serve...
... your client. In the event of a redirection, will your client handle it?
Does it examine the Location header? The answers to these
questions depend on the purpose of the client.
Does the client ... Socket; # include Socket
module
require 'tcp.pl'; # file with Open_TCP
routine
require &apos ;web. pl'; # file with parseURL
routine
use vars qw($opt_h $opt_i $opt_...
... that are useful for
client programming.
The LWP Module
The LWP module, in the context of web clients, performs client requests
over the network. There are 10 classes in all within the LWP module, ... module describes client requests, server responses, and
dates, and computes a client/ server negotiation.
The LWP module is the core of all web client programs. It allows the...
... In the
context of web client programming, you'll usually get an HTTP::Response
object from LWP::UserAgent and LWP::RobotUA. If you plan to write
extensions to LWP or a web server or proxy ... object.
LWP::RobotUA's constructor is a little different, though. Since we're
programming a web robot, the name of the robot and the email address of
the user are mandatory...
... programs with more
user-friendly options and features.
We present three broad categories of web client programs:
Simple clients programs that perform actions for users in real time,
usually with ... in Chapter 4, The Socket Library.
Periodic clients robots that perform a request repeatedly, with some
delay between each request. Periodic clients typically request the
same...
... references
if ($print_not _web) {
my %notweb = $site->not _web;
print "\nReferenced non-HTTP links:\n";
foreach $url (keys %notweb) {
print "notweb: $url\n";
}
} ... not http based
sub not _web {
my $self = shift;
%{ $self->{'not _web& apos;} };
}
# return associative array of encountered urls that
are local to the
# web server that w...
... program that will just prompt for the word
and go look it up without all that extra hassle. Anyone familiar with the
xwebster client for the X Window System will find xword to be vaguely
familiar, ... show a few examples of Tk-based web clients, which go
beyond the command-line interface that we've been using so far in this
book:[1]
xword, a dictionary client
track, a...