Википедија:Mrtva veza

Ova stranica je o mrtvim vezama u spoljašnjim vezama uopšteno govoreći. Za druge upotrebe pogledajte stranicu Vikipedija:Navođenje izvora § Sprečavanje i obnavljanje mrtvih veza.

Mrtva veza ili mrtvi link (engl. link rot — „trula veza”, „truli link”; engl. dead link — „mrtva veza”, „mrtvi link”) je hiperveza koja vodi na veb-stranicu koja ne postoji, koja je neispravna ili čiji je sadržaj promenjen u tolikoj meri da više ne može poslužiti prvobitnoj nameni.

Kao i većina velikih veb-sajtova, i Vikipedija ima problema sa mrtvim vezama, koje nastaju kada spoljašnje veze sa jedne od stranica veb-sajta — na Vikipediji često korišćene za navođenje izvora (referenciranje) u člancima — postepeno postanu delimično ili potpuno beskorisne iz više razloga od kojih su neki navedeni ispod:

• veb-stranica do koje veza vodi ne postoji ili je neispravna [na primer, na stranici se prikazuje HTTP greška 404 kao 404, Greška 404 (engl. Error 404), 404 Nije (pro)nađeno (engl. 404 Not Found), Nije (pro)nađeno (engl. Not Found) i sl.]
• sadržaj veb-stranice je promenjen u tolikoj meri da stranica više ne može poslužiti prvobitnoj nameni ili je promenjen u potpunosti [na primer, veb-sajt je promenio vlasnika i sada se stranica koristi za prikazivanje nekog sasvim drugog sadržaja i sl.]
• celi veb-sajt na kome se nalazi stranica ne postoji ili je neispravan [na primer, veb-sajt je ugašen ili se održava pa je rad servera privremeno zaustavljen i sl.]
• veb-sajt na kome se nalazi stranica je premešten na drugu veb-adresu [na primer, veb-sajt je iz nekog razloga odlučio da promeni ime ali nije napravio određenu vrstu direktnog preusmerenja na stare stranice koje su sada na sajtu sa novom veb-adresom i sl.]

Prekomeran broj mrtvih veza u člancima predstavlja značajnu i direktnu pretnju za narušavanje Vikipedijine politike pouzdanosti kao i Vikipedijinih smernica o navođenju izvora.

Napor koji je potrebno uložiti za sprečavanje pojavljivanja mrtvih veza je bitno manji od napora potrebnog da se iste obnove ili ublaži njihovo po članak destruktivno dejstvo. Zbog toga, sprečavanje pojavljivanja (a ne kasnije ulaganje većih napora za obnavljanje) mrtvih veza ojačava enciklopediju.

Ovaj vodič pruža određene strategije za sprečavanje pojavljivanja mrtvih veza pre nego se problem sa „zdravim” vezama uopšte i desi (pre nego što one postanu mrtve, neispravne i beskorisne). Ove strategije uključuju korišćenje internetskih servisa za arhiviranje te upotrebu šablona za navođenje izvora ne kršeći smernice po kojima bi trebalo da se oni navode. Svi uređivači Vikipedija se podstiču da kao deo bilo kog od šablona za navođenje izvora pored jednog URL-a ka određenoj veb-stranici uvek (tj. uvek kada je to moguće) dodaju i dodatni URL ka arhivskoj verziji stranice koju navode kao izvor za određeni navod u članku, ili barem u pomenute šablone postavljaju URL-ove referencirane za arhiviranje (oni URL-ovi koji su referencirani su „sigurni”/„pouzdani”, a biće korišćeni pri pravljenju arhivskih verzija stranice od strane nekog od servisa za arhiviranje), i to neposredno posle postavljanja navoda ili dorađivanja istog u članku koji uređuju.

Kako god, pojavu mrtvih veza je apsolutno nemoguće sprečiti ili u potpunosti iskoreniti, tako da ovaj vodič takođe objašnjava kako obnoviti što više mrtvih veza pronalaženjem prethodno arhiviranih verzija veb-stranica i/ili nekih drugih izvora umesto nedostupnog na koji mrtva veza vodi. Primenjivanje ovih strategija bi trebalo da bude u skladu sa svim smernicama o sprečavanju i obnavljanju mrtvih veza, koje opisuju pojedinačne korake koje treba poduzimati kada veza postane mrtva ili kada se mrtva ne može ili teško može obnoviti.

Ne brišite referencirani navod „samo” zato što URL koji vodi do sadržaja izvora za isti ne radi, jer načini za obnavljanje mrtvih veza i sprečavanje pojavljivanja istih postoje. Smernice o proverljivosti ne zahtevaju da svaka informacija na Vikipediji mora biti potkrepljena ispravnom vezom, niti zahteva da izvor mora uopšte i biti objavljen na internetu (onlajn). [Ovo važi za sve navode unutar članaka osim za one čiji se URL-ovi u spoljašnjim vezama ne koriste da bi ih potkrepili.]

Sprečavanje pojavljivanja mrtvih veza

Dok pišete članke, možete pomoći u sprečavanju truljenja linkova na nekoliko načina. Prvi način da sprečite truljenje linkova je izbegavanje golih URL-ova tako što ćete zabeležiti što je više moguće tačan naslov, autora, izdavača i datuma izvora. Po želji, dodajte i datum pristupa. Ako se veza pokvari, ove dodatne informacije mogu pomoći budućem Vikipedijancu, bilo uredniku ili čitaocu, da pronađe novi izvor za originalni tekst, bilo na mreži ili u štampanoj kopiji. Ovo verovatno ne bi bilo moguće samo sa izolovanim, golim URL-om koji više ne funkcioniše. Lokalne i školske biblioteke su dobar resurs za lociranje takvih vanmrežnih izvora. Mnoge lokalne biblioteke imaju interne pretplate na digitalne baze podataka ili ugovore o međubibliotečkoj pozajmici, što olakšava pronalaženje izvora koje je teško pronaći. Dok uređujete, ako članak ima gole URL adrese u citatima, popravite ih ili barem označite odeljak Reference sa Šablon:Linkrot kao podsetnik da dovršite detalje citata kao što je gore i da kategorizujete članak kao da treba da se počisti.

Servisi za veb-arhiviranje

Vidi još: Wikipedia:Citing sources/Further considerations § Pre-emptive archiving

A second way to prevent link rot is to use a web archiving service. The two most popular services are the Wayback Machine, which crawls and archives many web pages as well as having a form to suggest a URL to be archived,Using the web form at https://archive.org, enter a URL and click "browse history". This will either redirect to show the latest previously archived copy, present a box near the bottom of the page with a link inviting the user to "save this URL in the Wayback Machine", display a calendar showing the extent of previously archived content for that URL, or show an error message explaining why the URL cannot be archived. If archiving is attempted and ultimately successful, the archived copy usually becomes available within minutes.
Alternately, you can use the bookmarklets listed at Wikipedia:Citing sources/Further considerations#Archiving bookmarklets. The bookmarklets enable you to cause the page that you are viewing to be archived with a single click. A new tab will open with the progress of the archiving without disturbing the tab you are using to view the to-be-archived page. Bookmarklets are available for both Archive.org (the Wayback Machine) and WebCite.</ref> and WebCite, which provides on-demand web archiving. These services collect and preserve web pages for future use even if the original web page is moved, changed, deleted, or placed behind a pay wall. Web archiving is especially important when citing web pages that are unstable or prone to changes, like time sensitive news articles or pages hosted by financially distressed organizations. Once you have the URL for the archived version of the web page, use the archiveurl= and archivedate= parameters in the citation template that you are using. The template will automatically incorporate the archived link into reference.

• Dubner, Stephen J. (24. 01. 2008). „Wall Street Journal Paywall Sturdier Than Suspected”. The New York Times Company. Pristupljeno 28. 10. 2009. 
• Dubner, Stephen J. (24. 01. 2008). „Wall Street Journal Paywall Sturdier Than Suspected”. The New York Times Company. Arhivirano iz originala 15. 08. 2011. g. 

However, not every web page can be archived. Webmasters and publishers may use a Robots exclusion standard in their domain to disallow archiving, or rely on complicated javascript, flash, or other code that can't easily be copied. In these cases, alternate methods of preserving the data may be available.

Robots.txt

A quirk in the way the Wayback Machine operates means archived copies of sites sometimes become unavailable, for example, the Freakonomics blog previously hosted at freakonomics.blogs.nytimes.com. Those URLs were then excluded from archiving by the New York Times' robots.txt file. This had the unfortunate effect of also rendering the previously archived content unavailable. But robots.txt changes can unhide that which previous changes have hidden, so do not delete an archiveURL solely because the archived content is currently unavailable. Luckily, in this case, not only can the content be found on a new site that is still open to archiving, but the site's robots.txt later changed to allow archiving again, and so the old archives are now unhidden (example).

Alternativne metode

Most citation templates have a quote= parameter that can be used to store text quotes of the source material. This can be used to store a limited amount of text from the source within the citation template. This is especially useful for sources that cannot be archived with web archiving services. It can also provide insurance against failure of the chosen web archiving service.

• Dubner, Stephen J. (24. 01. 2008). „Wall Street Journal Paywall Sturdier Than Suspected”. The New York Times Company. Arhivirano iz originala 30. 04. 2008. g. „'...the Wall Street Journal will not, as has been widely speculated, tear down its paywall entirely...'” 

When using the quote parameter, choose the most succinct and relevant material possible that preserves the context of the reference. Storing the entire text of the source is not appropriate under fair use policies, so choose only the most important portions of the text that most support the assertions in the Wikipedia article.

A quote also helps searching for other on-line versions of the source in the event that the original is discontinued.

Where applicable, public domain materials can be copied to Wikisource.

Obnavljanje mrtvih veza

There are several ways to try to repair a dead link, detailed below:

Pretraga sajta

Often web pages have simply moved, either in connection with a migration to a new server, or through general site maintenance. A site index or site-specific search feature is a useful place to locate the moved page.

Veb-pretraživač

A search engine query using the title of the page, possibly with a search restriction to the same site, might also find the page. Using the examples from above, a web search (such as Google, Yahoo, etc.) might look like one of these:

site:freakonomics.blogs.nytimes.com/ "Wall Street Journal Paywall Sturdier Than Suspected"

site:nytimes.com/ "Wall Street Journal Paywall Sturdier Than Suspected"

"Wall Street Journal Paywall Sturdier Than Suspected"

Also, a search for some components of the dead link with punctuation removed is often fruitful; e.g. a search through Google for

groups.csail.mit.edu sFFT paper pdf

leads to a page enabling this fix. A search for an unusual or unique-looking substring of the URL, such as just the filename at the end, is often fruitful.

Veb-arhive

Check for archived versions of the page in the archiving services. If you find an archived version of the dead link, double-check to make sure that citation still supports the article text. It is also a good idea to consult the access date of the citation (if it was specified, or a history search for when it was added) to see how contemporaneous this archived version is to the link when it was cited.

The following archiving services are considered to be reliable:

• Internet Archive Wayback Machine at https://archive.org/
• WebCite at http://www.webcitation.org/query
• UK Government Web Archive at http://webarchive.nationalarchives.gov.uk/

The Mementos interface allows you to search multiple archiving services for archived versions of some pages with a single request using the Memento protocol. Unfortunately, the Mementos webpage interface removes any parameters which are included with the URL. If the URL contains a "?" it is unlikely to work properly when entered manually without changes. When entering the URL into the Mementos interface manually, the most common change needed is to change "?" to "%3F". While making only this change will not be sufficient in all cases, it will work most of the time. The bookmarklet in the table below will properly encode URLs such that searches will work. Mementos looks like it is, or at least will be, very convenient. However, if archives are not found at Mementos, it should not be the only site checked. Mementos can sometimes return no results when archives exist at sites which it normally includes. An example of this is trying to find archives of Battle of the Atlantic. Ažurirano: April 2014., Archive.org reports it has 63 or 64 archives (https, http). Mementos reports 0 archives (https, http). Mementos usually finds archives at Archive.org, but sometimes Mementos does not even when archives exist. If you try Mementos first, don't assume that there really are no archives if Mementos reports that there are none.

There are many Internet archive projects in existence.

When multiple archive dates are available, try to use the one that is most likely to be the contents of the page seen by the editor who entered the reference on the |accessdate=. If that parameter is not specified, a search of the article's revision history can be performed to determine when the link was added to the article.

View the archive to verify that it contains valid page information. Sometimes archives are actually archives of the fact that the link is dead, or that the archiving failed. If this is the case, try using an archive from a different date. Usually dates closer to the time the link was placed in the Wikipedia page, or earlier, are more likely to show valid information. Different archiving sites should also be tried.

For most citation templates, archives are entered using the |archiveurl=, |archivedate= and |deadurl= parameters. The primary link is automatically switched to the archive when |deadurl=yes. This retains the original link location for reference.

Bookmarklets to check common archive sites for archives of the current page
(all open in a new tab or window)

Archive site	Bookmarklet
Archive.org	javascript:void(window.open('https://web.archive.org/web/*/'+location.href))
WebCite	javascript:void(window.open('http://www.webcitation.org/query.php?url='+location.href))
Wikiwix	javascript:void(window.open('http://archive.wikiwix.com/cache/?url='+location.href))
Mementos interface	javascript:void(window.open('http://www.webarchive.org.uk/mementos/search/'+encodeURIComponent(location.href)+'?referrer='+encodeURIComponent(document.referrer)))

The following archiving services are not permitted on the English Wikipedia:

• archive.is See WP:Archive.is RFC and WP:Archive.is RFC 3 for more information.

Ublažavanje po članak destruktivnog dejstva mrtvih veza

At times, all attempts to repair the link will be unsuccessful. In that event, consider finding an alternate source so that the loss of the original does not harm the verifiability of the article. Alternate sources about broad topics are usually easily located. A simple search engine query might locate an appropriate alternative, but be extremely careful to avoid citing mirrors and forks of Wikipedia itself, which would violate Wikipedia:Verifiability.

Sometimes, finding an appropriate source is not possible, or would require more extensive research techniques, such as a visit to a library or the use of a subscription-based database. If that is the case, consider consulting with Wikipedia editors at Wikipedia:WikiProject Resource Exchange, the Wikipedia:Village pump, or Wikipedia:Help desk. Also, consider contacting experts or other interested editors at a relevant WikiProject.

Zadržavanje mrtvih veza

A dead, unarchived source URL may still be useful. Such a link indicates that information was (probably) verifiable in the past, and the link might provide another user with greater resources or expertise with enough information to find the reference. It could also return from the dead. With a dead link, it is possible to determine if it has been cited elsewhere, or to contact the person originally responsible for the source. For example, one could contact the Yale Computer Science department if http://www.cs.yale.edu/~EliYale/Defense-in-Depth-PhD-thesis.pdf were dead. Place {{dead link}} after the dead URL and just before the </ref> tag if applicable, leaving the original link intact. Placing {{dead link}} auto-categorizes the article into Articles with dead external links project category, and into specific monthly date range category based on |date= parameter. Do not delete a URL just because it has been tagged with {{dead link}} for a long time.

Automatizovane alatke

There have been bots that proactively and automatically archive external URLs used in Wikipedia articles. None are currently working.

There have been bots (the semi-automated RjwilmsiBot (razgovor · doprinosi) ) that automatically identify and flag dead links with {{dead link}}. No bots currently attempt to repair dead links or add an archivedate= field to citations with just an archiveurl= field.

Mrtve veze na ne-Vikimedijinim sajtovima

Non-Wikimedia sites are also susceptible to link rot. Following a page move or page deletion, links to Wikipedia pages from other websites may break. In most page moves, a redirect will remain at the old page — this won't cause a problem. But if a page is completely deleted or usurped (i.e. replaced with other content) then link rot will have been caused on any external websites that link to it.

Replacement of page content with a disambiguation page may still cause link rot, but is less harmful because a disambiguation page is essentially a type of soft redirect that will lead the reader to the required content. If a page is usurped with content for another subject that shares its name, a hatnote may be placed at the top that directs readers to the original content on its new page — this again is a type of soft redirect, but less obvious. In these cases, readers arriving from an external rotten link should be able to find what they're looking for, but the situation is best avoided as they would have to get there via an additional page, potentially giving a poor impression of both Wikipedia and the linking website.

It will be impossible to tell how many, if any, external web pages will be affected by a move or deletion, but the risk of link rot will probably be greatest on older and higher profile pages. In truth, there is not a lot that can be done; maintenance of non-Wikimedia websites is not within the scope of being a Wikimedian, nor in most cases within our capability (although if they can be fixed, it would be helpful to do so). However, it may be good practice to think about the potential impact on other sites when deleting or moving Wikipedia pages, especially if no redirect or hatnote will remain. If a move or deletion is expected to cause significant damage, then this might be a factor to consider in WP:RM or WP:AFD discussions, although other factors may carry more weight.

Vidi još

• List of HTTP status codes.
• Wikipedia:Citing sources#Preventing and repairing dead links.
• Wikipedia:External links#Longevity of links—prescribes removal of dead URLs from the "External links" section.
• Wikipedia:Offline sources—essay.
• Wikipedia:Using the Wayback Machine—how-to guide.
• Wikipedia:Using WebCite—how-to guide.
• Wikipedia:Citing_sources/Further_considerations#Pre-emptive_archiving—brief guide on how to use various archiving services.
• WikiProject External links—dedicated to cleaning up overly long lists of external links and having articles conform to Wikipedia's external links guidelines.
• Category:Articles needing link rot cleanup—the backlog of articles containing bare URLs at risk of link rot, sub-categorised by month.
• Category:Articles with dead external links—the backlog of articles containing dead links, sub-categorised by month.
• Special:LinkSearch—to find all the pages that contain a particular URL.

Botovi

• WP:STiki/Dead_links—Page reporting NEWLY added dead links, a component of the STiki project.
• User:MerlLinkBot—purpose is to change links in articles which are outdated and can be successfully replaced by a new one. Submit requests for link updates to the bot's talk page.
• User:Legobot—can mass tag links with {{dead link}}. Requests can be made at User talk:Legoktm.

Spoljašnje veze

• weblinkchecker.py—script from the Python Wikipedia Bot collection which finds broken external links.
• UndeadLinks.org—allows you to search for a broken link's new address.
• Resurrect Pages—add-on for Firefox, provides links to seven cache/archive websites upon coming across a dead link.
• 404-Error?—add-on for Firefox, automatically brings you to the archive.org version upon coming across a dead link.
• PageHistory—addon for Safari.
• Webcache—add-on for Opera.
• Web Cache—add-on for Chrome.
• Internet Archive
• BrokenWikiLinks Twitter bot—tweets about pages with broken links