Programming the network with perl

... Scaling the Network with NAT and PAT ©© 2002, Cisco Systems, Inc All rights reserved 2002, Cisco Systems, Inc All rights reserved ICND v2.0— 6-2 Objectives Upon completing ... lists denying the packets from entering the NAT router – The access list referenced by the NAT command is permitting all necessary networks – There are enough addresses in the NAT p...

Ngày tải lên: 06/03/2014, 15:20

... assign the socket to a particular port on the host The server then uses the listen( ) and accept( ) routines to establish communication on that port On the other end, the client also uses the socket( ... then converses with the client using whatever protocol they agree on (e.g., HTTP, NNTP, SMTP, etc.) Initially, the server uses the socket( ) system call to creat...

Ngày tải lên: 20/10/2013, 10:15

... the location specified by 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 ... example, if the URL used by the client becomes obsolete or is changed, the client may interpret the entitybody incorrectly Media types for the URL may change, and coul...

Ngày tải lên: 20/10/2013, 10:15

... 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, as shown ... computes a client/ server negotiation  The LWP module is the core of all web client programs It allows the client to communicate over the network with t...

Ngày tải lên: 24/10/2013, 08:15

... invoked with no parameters, this returns the default port for the URL defined in the object The default port is based on the scheme used Even if the port for the URL is explicitly changed by the ... user with the port( ) method, the default port is always the same $url->epath( ) When invoked with no parameters, this returns the escaped path of the URL defined i...

Ngày tải lên: 24/10/2013, 08:15

... Network Programming with Perl Graham Barr Agenda     Introduction Properties of a socket ... Ä Ä Ä Creates a generic socket with socket Binds to a known address with bind Tell system to watch for incoming connections with listen Waits for a connection with accept or select Slide The ... server  Case studies Common problems Commonly used network protocols IO::Socket, w...

Ngày tải lên: 21/12/2013, 04:19

... example, the browser is given the following URL: http://hypothetical.ora.com/ The browser interprets the URL as follows: http:// In the first part of the URL, you told the browser to use HTTP, the ... beginning with the string User-Agent, the client identifies itself as Mozilla (Netscape) version 3.0, running on Windows NT The fourth line tells the server what the...

Ngày tải lên: 26/01/2014, 07:20

... a document to transmit to the client Or the URL may actually be a program, the output of which is sent to the client Finally, the last entry on the first line specifies the version of HTTP the ... as the current time or the path through a network that the client and server are using Request headers tell the server more information about the client The clie...

Ngày tải lên: 26/01/2014, 07:20

... the 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-Since, et al To accommodate client- side caching of documents, the client can use the IfModified-Since header with the GET method When using this option, the client req...

Ngày tải lên: 17/10/2013, 19:15

... behaviors that a client may exhibit The examples in this chapter all use a simple command-line interface In Chapter 7, Graphical Examples with Perl/Tk, we have some additional examples with a graphical ... extension to Perl Simple Clients Simple clients are programs that perform actions for users in real time, usually with a finite list of URLs to act upon In this section, we'll show...

Ngày tải lên: 28/10/2013, 15:15

... print non-HTTP references if ($print_not _web) { my %notweb = $site->not _web; print "\nReferenced non-HTTP links:\n"; foreach $url (keys %notweb) { print "notweb: $url\n"; } } # print reference list ... $touched{$URL}=1 (URLs that have been visited) # %notweb $notweb{$URL}=1 if URL is non-HTTP # %badlist $badlist{$URL}="reason" (URLs that failed Separated with \n) getopts('avlrRnbhm:p:e:d:...

Ngày tải lên: 28/10/2013, 15:15

... simple 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, ... handler for the graphical interface The most important concept to understand with Perl/Tk is that the program won't a single thing until it hits the MainLoop statement You won't se...

Ngày tải lên: 07/11/2013, 09:15