FR2777725A1 - COMPUTER SYSTEM FOR MANAGING LINKS AND METHOD FOR IMPLEMENTING SUCH SYSTEM - Google Patents

Abstract

The invention concerns mainly a computer system for managing links, in particular hypertext links, and a method using such a system, characterised in that it comprises a server (3) for changing links which collects information on the pages (1.1), in particular in HTML comprising links, preferably external, on page address modifications and page cancellations. When a modification or cancellation occurs, the server (9) for changing links informs the web servers (1) concerned indicating the former page addresses. The invention is mainly applicable to pages comprising links on the World Wide Web.

Description

COMPUTER SYSTEM FOR MANAGING LINKS

  AND METHOD USING THE SAME

  The present invention relates mainly to a computer system for managing links, in particular hypertext links, and to a method implementing such a system. The network of INTERNET networks ensuring the permanent interconnection of computer networks, experiencing a growing success due, on the one hand to the ease of access to the network by a temporary connection, including a telephone connection to a computer of a provider of access (provider in English terminology) connected to INTERNET and, on the other hand, to the ease of finding information described in the language of

  description of HTML pages of a subset of INTERNET called World

  Wide Web or WWW in English terminology. The pages described in HTML are interpreted and displayed by browser software i5 (browser in English terminology) including software NAVIGATOR NETSCAPE Company or INTERNET EXPLORER MICROSOFT Company. Each INTERNET computer is assigned a permanent or temporary IP address consisting of a sequence of numbers separated by periods. However, to connect via INTERNET to a computer having pages in HTML to display, called web server, it is sufficient for a user to know his domain name normally composed of a string like: http://www.xxx.com/ INTERNET ensures the transcoding of domain names into corresponding IP addresses. Likewise, every document on the web is identified by a string of characters called URL (or Universal Resource Locator

Anglo-Saxon terminology).

For example:

  http://www.xxx.com/abc/divers/mapage.html is the URL of the page called "mapage", described in HTML, located in the miscellaneous subdirectory of the abc directory of the web server www.xxx.com . The web offers a facility of navigation and a great user-friendliness thanks to the presence of links whose selection, in particular by clicking on it, in a page described in HTML language makes it possible to carry out various actions: - to move on a page (towards a bookmark ); - move to another page of the document (same server, internal links); - send messages to an e-mail inbox (e-mail in English terminology) or - move to a page on another web server (external link). An external link to the default page of the miscellaneous subdirectory of the abc directory of the server www.xxx.com is written in HTML: <a href = "http://www.xxx.com/abc/divers/" > Links are by default on the HTML page as underlined blue text. This text embedded in the page code following the link is terminated by the character string <a/> Other presentations may be declared (such as other colors, images, etc.). When switching to a link, the cursor

  transforms into a drawing representing a hand pointing upwards.

  This mode of navigation in which the user does not have to know, nor, a fortiori, to enter the URLs, confers an unequaled user-friendliness to the web. However, if the links point to an erroneous address, we get the display of an unwanted page, whereas if the URL of the link is not valid, the error 404 of the HTTP protocol with the display occurs. a message of the type:

FILE NOT FOUND

  The requested URL / xyz.htm was not found on this server.

  Such an exception exceptionally results from an error in entering the URL of the link or, more frequently, a page that has been moved or deleted. We are talking about a broken link. The appearance of such a message seriously compromises the usability of the consultation. This is particularly true for external links for which the website manager (webmaster in English terminology) does not have a link consistency check tool and is not necessarily informed of the change of the addresses of the designated pages. by the links. To remedy this problem, it has been proposed to replace the links with URN or Universal Resource Name invariant symbolic names in English terminology. A centralized server would ensure URL translation in invariant URNs. Thus, only the name server would know the physical location of the documents, thus preventing this information from being stored redundantly by all the servers that make use of it. This centralized server would be easier to update. Such a solution has never been adopted on the INTERNET because it has many disadvantages. On the one hand, to connect to a site, it would first connect to the name server, which would double the number of connections and, therefore, the time of obtaining the desired information. In addition, the name server would be queried by many web servers and become a bottleneck

  throttling extremely penalizing for the transmission of information.

  It is therefore an object of the present invention to provide a computer system to prevent the appearance of broken links,

especially on the World Wide Web.

  It is also an object of the present invention to provide such

  system generating low traffic on the network.

  It is also an object of the present invention to provide a

  system with high operational safety.

  It is also an object of the present invention to provide a system for updating bookmarks designating favorite sites at the level of

  navigation software for individual consultation positions.

  These objects are achieved by a computer system according to the present invention comprising a link change server which collects the information on the pages, in particular in HTML including links, preferably external, on the modifications of the addresses of pages as well as on deletions of pages. When modifying or deleting the page, the link change server informs the concerned web servers designating the old addresses

pages.

  Advantageously, the collection of information on the pages with links is carried out in cooperation with the web server

hosting these pages.

  Advantageously, the notified change is automatically executed on the server hosting the page containing the link to

edit.

  The present invention will be better understood by means of the

  description below and accompanying figures given as examples

  non-limiting and in which: - Figure 1 is a diagram of some computers connected to the INTERNET with valid links; FIG. 2 is a similar diagram of computers after modification of links; FIG. 3 is a flowchart illustrating the operation of a module called transmitter providing the census of o links to be monitored; FIG. 4 is a flow diagram of a link change notification reception process; FIG. 5 is a flow diagram of the URL modification notification receiving process; and FIG. 6 is a flow diagram of a module providing the

  receipt of notification of change of URL.

  In FIGS. 1 to 6, the same references are used for

designate the same elements.

  In FIGS. 1 and 2, three web servers 1, 3 and 5 connected via INTERNET 7 to a link server 9, a conventional consultation station 11 and a consultation station 13 can be seen.

according to the present invention.

  The pages usually published on the web are described in HTML and are defined, on the one hand by the name and location of the file stored on the server and, on the other hand, possibly by their name embedded in the code. of the page with the <title> tag. Server 1 provides access to pages 1.1, 1.2, 1.3, 1.4 and 1. 5

  described, for example, in HTML.

  The server 3 provides access to pages 3.1, 3.2 and 3.3 described for example in HTML. The server 5 provides access to

  pages 5.1, 5.2 and 5.3 described for example in HTML.

  However, it is understood that the present invention is not limited to the use of HTML but applies to any

  description of a content to create links including

  hypertext, for example using the page description languages

  SGML, XML, DHTML, ASP, HYPERCARD software from APPLE

  or document management software.

  Page 1.1 has a first link 15.1 to go back to the top of the page without using the scroll bars. A link 15.2 points to page 1.3. Links 15.1 and 15.2 are internal links that are relatively easy to manage. On the one hand, site creation software

  can incorporate internal link consistency management tools.

  On the other hand, all pages 1.1 to 1.5 are normally under the

  responsibility of the same person, the webmaster of the web server 1.

  A link 15.3 points from page 1.1 to page 3.2 of Server 3. A 15.4 link points from page 1.1 to page 3.1 of Server 3. A 15.5 link points from page 1.1 to page 5.3 of Server 5. Links 15.3 to 15.5 are external links in that they point to pages stored on other servers than server 1 hosting page 1.1. A user using a consultation station 11, typically a microcomputer equipped with a browser and page browsing software such as INTERNET EXPLORER, can connect to the server 1 and display on his computer page 1.1. The links 15.1 to

  15.5 facilitate the navigation of information.

  Other links, not illustrated, can point to images, to JAVA applets or others. A link pointing to the image me.gif of the abc directory of the server www.xxx.com is written in HTML: <img src = "http://www.XXX.com/abc/moi.gif"> By clicking on one of the links, the user changes pages or places on the page without knowing or having to enter the URLs of the various pages designated by the links 15.2 to 15.5 or the bookmark pointed by the link 15.1. This situation can be disrupted, as shown in Figure 2, by the disappearance or displacement of certain pages designated by links, including external. In addition, the location of certain pages on web servers is kept only precisely to avoid causing a break in links designating these pages. The server hosting these pages

  having evolved, the webmaster freezes the structure to avoid breaking links.

  In the example of Figure 2, link 15.3 is broken because page 3.2 has been removed. The contents of page 5.3 have been moved to page 5. 1 of web server 5. The contents of page 3.1 are moved to the

page 5.5 of the web server 5.

  Thus, a user of the consultation station 11 connected to the INTERNET will see his consultation disrupted if the links 15.3, 15.4 and 15. 5 are not updated. This update is not easy to the extent that the webmaster of computers 3 and 5, without very heavy searches on the web can not know what are the links that point to the pages

hosted by their servers.

  According to the present invention, a list of links to warn about the modification or deletion of a page (servers 3 and 5) is generated and kept up to date by the server (1) presenting links pointing to the

  o pages moved or nonexistent.

  After rectification, the link 15.3 relates to Figure 2 reference 15. 3 '. After rectification, the link 15.4 relates to FIG. 2 reference 15.4 '. After rectification, the link 15.5 relates to Figure 2 the reference 15.5 '. After correction, the link 15.6 relates to FIG.

reference 15.6 '.

  According to the preferred example of the present invention, a link server 9 stores and maintains the list of external links on the INTERNET, in particular on the World Wide Web. If a dotted page changes, it warns the affected servers with links pointing to that page. Advantageously, the list is generated and / or maintained in a cooperative manner with the web servers which declares the creation, the modification, the destruction or the displacement of pages, as well as the pages pointed by the links of the hosted pages. This cooperation is particularly important for servers with restricted access, in particular with INTRANET servers or servers requiring an access password for which page browsing by a computer robot, and

  consequently the extraction of the links of the pages hosted, are not possible.

  In a variant embodiment, the navigation software of the consultation stations 13 also declare to the link server 9 the favorite sites or the consultation bookmarks on the web as well as, possibly, their e-mail addresses. In the event of a change of address of a site or the pages of a site, the server 9 signals to the consultation stations 13 equipped with navigation software according to the present invention the updates to be made or, in the case of direct connection to the server 9, performs the

change.

  For example, the consultation station 13 includes a shortcut 15.6 to the page 3.1 of the web server 3. After notification by the link server 9, the shortcut 15.6 'of the consultation station 13 points to

page 5.5 of the web server 5.

  On the other hand, the same link 15.6 to page 3.1 starting from a consultation station 11 of known type is not modified automatically and

  consequently points to a page that is no longer relevant.

  As a variant, when detecting a broken link (HTTP error 404), the navigation software does not display the associated messages but connects to the link server 9 to read the new address of the page to be pointed. Thus, the link server 9 is only consulted for broken links,

  which limits the traffic on INTERNET 7.

  Advantageously, the computer system according to the present invention comprises a link information transmitter module installed on the various web servers, illustrated in FIG. 3, a link server 9 equipped with a link information reception module. illustrated in FIG. 4, a module for acquiring or receiving information on the modification of the pages on the various web servers, illustrated in FIG. 5 and the receiving modules illustrated in FIG. 6, advantageously distributed on the various web servers ensuring receipt of information about the pages

  modified by the links of the receiving server.

  The receiver module of FIG. 3 comprises a step 16 of storage in a difference file A of the history of the modifications of the addresses of pages. As a variant, any modification (deletion, displacement) of the page is immediately notified to the link server 9 without waiting for the creation of the scanning file A of all the pages hosted in search of the links to be processed. Preferably this scan is limited to external links. We go to 17. The scanning step 17 consists for example in the search in the code of the pages of the string of the type <a href = protocol://server/directory/file> o: protocol designates the protocol used , for example HTTP; server is the address or designation of the hosting server;

  directory refers to the directory and any sub-

  code file storage directories; and

  file is the name of the code file that forms the page.

We go in 19.

  In 19, we establish the list at instant i of all the links to be treated

(including external links).

  List i also includes logical locations

  corresponding to the various HTML pages.

We go in 21.

  In 21, we check if there is an earlier list.

If so, we go to 23.

If not, we go to 25.

  In 23, the current list (list i) is compared with the previous list (list i-1) and the difference is stored in a difference file A.

We go in 27.

  In 25, the current list (list i) is stored in the difference file A.

We go in 27.

  In 27, the list A is transmitted to the link server 9. As a variant, the list A, possibly completed by the more or less complete history of the evolutions of the various pages hosted by the server is set

  available for consultation via the INTERNET.

  For example, list A includes page adding messages, new pages added, page changes for renamed or moved pages, page deletions for deleted pages, link additions for new external links created , the modification of links indicating modified links and the removal of links concerning deleted links. For example, server 3 notifies the link server that page 3.2 has been removed and page 3.1 has been changed while web server 5 indicates pages 5.1 and 5.3 have been changed and pages 5.4 and 5.5 have changed.

been added.

  The transmission 27 can be done by email, the procedure can be done automatically or after validation by the webmaster of the issuer to check the consistency, accuracy and absence of confidential information in the notification to the link server 9. The transmission can also be carried out according to the TCP / IP network transmission protocol, in particular on the web server interrogation.

by the link server 9.

  The transmission 27 can also be performed by a high-level protocol of the HTTP type. For example, the link server 9 connects to the web server and executes a standard script, for example according to the standard termed in Common Gateway Interface or CGI terminology and advantageously executes a preference script written in PERL language which is particularly optimized for handling arbitrary strings. The script displays the list of the file A which is retrieved by the link server 9. The link server 9 traverses all the web servers declaring to include a sender module. File A is advantageously

deleted on the web server.

  In a general manner the transmission 27 can be done by any protocol understandable by the recipient, such as for example the voice synthesis or a fax addressed to the webmaster of the server concerned. In FIGS. 4 and 5, the operation of the

link server 9.

  At 29, the server receives, by e-mail, transmission in TCP / IP mode or in HTTP mode of the files A.

We're going to 31.

  In 31, the link server 9 updates the database 32 links, including external links on the World Wide Web. Alternatively, it also receives bookmark or favorite

  station navigation software 13 according to the present invention.

  In 33 (Figure 5) the link server receives the notifications of the URL changes of the web pages. Information about these changes can be included in A files or stored and transmitted

separately.

  Alternatively, in non-cooperative mode, the link server 9 scans the various web servers to form the list of web pages, their location and the links they contain. This list can also be developed from the indexing database of the INTERNET developed by the search engines and including indexing links. The

  9 web server advantageously assigns a compact signature to the page.

  This signature includes the <title> tag among HTML pages complemented, preferably, by relevant page identification data based on the occurrences of words, images, the layout used and / or by semantic analysis of the text or the check sum, that is the value, for example weighted, of the sum of the values of the characters composing the

  page, in order to facilitate the identification of the pages moved.

  Alternatively, the server 1 hosting pages with external links 15.3 to 15.5 to pages 3.1, 3.2, 5.3 hosted by other web servers 3, 5 notifies them the existence and content of these links. In return, a server 3, 5 moving 3.1, 5.1 or deleting 3.2, a page notifies these changes to the servers having informed them that they are hosting pages

  with links to modified pages.

We go in 35.

  In 35, the link server 9 scans the link database to establish a list of possible links affected by the changes or deletions of the pages, that is to say the list of pages with links

which are now broken.

We go in 37.

  In 37, the link server 9 notifies the web servers with the broken links the changes, displacements or deletions

pages.

  This notification can also be done by e-mail, notification in TCP / IP transmission mode, transmission of

HTTP type or other.

  The operation of a notified web server 1 is illustrated on the

figure 6.

  In 39, the server 1 receives a notification of change of the

  URLs of pages identified by links 15.3 to 15.5.

We go in 41.

  In 41, the webmaster advantageously performs a validation of the proposed changes. In case of refusal of validation, we go to 43. This lack of validation can come from an uncertainty about the origin

  the message received in 39 or its relevance.

In case of validation, we go to 45.

  In 45, we make the changes to the URLs in the pages

  HTML 1.1 concerned. The program ends in 43.

  The sending and receiving modules on the various servers 1, 3 or 5 can be carried out periodically, on manual triggering of the webmaster, especially after a modification of the pages or run in the background with activation especially in case of modification of the HTML pages. For example, on the server running on the UNIX operating system, these modules may consist of programs called DAEMON while on servers running on the WINDOWS NT operating system, they may be modules called SERVICES. Advantageously, in a mixed cooperative-non-cooperative mode, the robot browsing the World Wide Web to constitute a database of the URLs of the HTML pages and the links they contain, avoids the exploration of the cooperative servers having made a notification of As a variant, when a server 3 or 5 modifies or deletes a page, it makes a connection to the link server 9 to inquire about the list of servers 1 comprising pages 1.1 comprising links 15.3, 15.4, 15.5. pointing to a modified page and makes the

server notifications 1.

  It may be extremely advantageous to provide the system according to the present invention with security devices preventing false notification, including malicious notifications and / or attempts to create unwanted links. Any known type of security system may be used, including the authentication of the message author and the integrity of the content. For example, messages can be encrypted, for example with so-called public key encryption algorithms, such as RSA or DSA, PGP or the PGP / Mime or S / Mime protocols. Public key cryptography systems are described in US-A-4,200,770, US-A-4,218,582, US-A-4,405,829, US-A-4,424,414 and US-A-4,995,082, for example. as well as in the book

  "Applied cryptography", second edition, by Bruce Schneier.

  Alternatively, one can also use the automatic callback mechanism (call-back in English terminology). The called server recalls the sender of the message with incorporation of a random number of authentication. The answer includes the random number or a

  number derived from the random number of authentication.

  The present invention applies to any computer system including links, including external, such as document management system, LAN, messaging. The present invention applies primarily to pages with links on the World Wide Web.

Claims (14)

  A computer system comprising data storage means storing links and / or shortcuts to display pages, means for automatically identifying stored links or shortcuts, means for automatically generating and storing a list of couples (location of the link (1.1.), link (15.3, 15.4, 15.5)), and means of making this list available to allow, in case of change of the address of a page (3.1, 3.2 , 5.3) indicated by a link (15.3, 15.4, 15.5), to notify this change with a view to correcting the link (15.3 ', i0 15.4 ', 15.5') corresponding.   2. System according to claim 1, characterized in that said system is a server on a network, in particular a server on the INTERNET, preferably a web server (1) and in that the means for identifying the links comprise reading means. the code of the pages of display and the means of extraction of the external links of the pages Display (1.1).   3. System according to claim 2, characterized in that the   Display pages are described in HTML or XML.   4. System according to any one of the claims   preceding, characterized in that it further comprises means for transmitting the list of couples (location of the link (1.1), link (15. 3,   15.4, 15.5)) to a link server (9).   5. Computer system according to claim 1, characterized in that said system is a position (13) for online consultation of websites (1, 3, 5) and in that it comprises memory storage means   shortcuts (1 5.6) to favorite sites or favorite pages.   6. A link server characterized in that it comprises means for developing a list of links and / or shortcuts pointing to pages of the World Wide Web, means for determining address changes of the pages pointed ( 3.1, 3.2, 5.3) and means for notifying a computer system (1, 13) hosting the link support   or shortcut the address changes of the dotted page.   7. Server according to claim 6, characterized in that it comprises means for receiving notification of the lists of couples [locations (1.1), link (15.3, 15.4, 15.5)] transmitted by a system.   computer according to claim 4 or 5.   8. Server according to claim 6 or 7, characterized in that it comprises means for viewing viewing pages published on the web (1.1), means for extracting external links embedded in the code of said pages, means for developing and storing a list of original page pair (1.1), link (15.3, 3.2; 15.4, 3.1; 15.5, 5.3), as well as means for producing a list of pages comprising links to each page processed.   9. Web server according to claim 2, 3 or 4, characterized in that it further comprises means for notifying changes.   o addresses of web pages (3.1, 3.2, 5.3).   10. Server according to claim 6, 7 or 8, characterized in that it comprises means for consulting web pages, means for identifying web pages, means for storing couples (identification of a web page, its address on the web) and means of comparison of the addresses of the previous web pages with addresses of the current web pages to deduce a list of the identification of web pages having changed address accompanied by their address as well as web pages gone.   11. A method of repairing broken links on the INTERNET, in particular on the World Wide Web characterized in that it comprises the steps of: receiving notifications of links or shortcuts pointing to web pages; - to receive the notifications of the modifications of addresses of the web pages; - develop a list of web pages pointing to pages having changed address; - notify the computer system hosting the links pointing to web pages whose address has been modified, the change address of the dotted web pages.   12. A method of repairing broken links or shortcuts, characterized in that it comprises the steps of: - consulting the web pages accessible on the world wide web and extracting the external links pointing to web pages hosted on other sites ; - memorize the addresses of the various web pages pointed by links or shortcuts; - develop a list of web pages pointing to pages having changed address; s - notify the computer system hosting the links pointing to web pages whose address has been modified, the change address of the dotted web pages.   13. The method of claim 12, characterized in that it further comprises a step of modifying links pointing to   web pages whose address has been modified to the corresponding addresses notified.   14. The method of claim 11 or 13, characterized in that it further comprises a step of notifying a server hosting   links pointing to pages whose address has been modified, isolated by means of restriction and authorization of access, in particular to an INTRANET server.