Por que este XMLStarlet Query não funciona?

Question

Estou tentando escrever um script simples que analisa as informações de preço dos resultados da pesquisa da API do desenvolvedor do ebay. Aqui está um exemplo de resultados de pesquisa XML para "Detective Comics 700":

<findItemsAdvancedResponse xmlns="http://www.ebay.com/marketplace/search/v1/services">
<ack>Success</ack>
<version>1.12.0</version>
<timestamp>2014-06-21T19:03:49.943Z</timestamp>
<searchResult count="1">
<item>
<itemId>301209856743</itemId>
<title>
DETECTIVE COMICS (1937 Series) #700 Near Mint Comics Book
</title>
<globalId>EBAY-US</globalId>
<primaryCategory>
<categoryId>77</categoryId>
<categoryName>Other</categoryName>
</primaryCategory>
<galleryURL>
http://thumbs4.ebaystatic.com/m/mBYOI1SLUSGe0DL1FmHjdCw/140.jpg
</galleryURL>
<viewItemURL>
http://www.ebay.com/itm/DETECTIVE-COMICS-1937-Series-700-Near-Mint-Comics-Book-/301209856743?pt=US_Comic_Books
</viewItemURL>
<paymentMethod>PayPal</paymentMethod>
<paymentMethod>VisaMC</paymentMethod>
<paymentMethod>Discover</paymentMethod>
<autoPay>false</autoPay>
<location>USA</location>
<country>US</country>
<shippingInfo>
<shippingServiceCost currencyId="USD">4.95</shippingServiceCost>
<shippingType>Flat</shippingType>
<shipToLocations>Worldwide</shipToLocations>
<expeditedShipping>true</expeditedShipping>
<oneDayShippingAvailable>false</oneDayShippingAvailable>
<handlingTime>3</handlingTime>
</shippingInfo>
<sellingStatus>
<currentPrice currencyId="USD">6.0</currentPrice>
<convertedCurrentPrice currencyId="USD">6.0</convertedCurrentPrice>
<sellingState>Active</sellingState>
<timeLeft>P17DT7H31M1S</timeLeft>
</sellingStatus>
<listingInfo>
<bestOfferEnabled>false</bestOfferEnabled>
<buyItNowAvailable>false</buyItNowAvailable>
<startTime>2014-06-09T02:34:50.000Z</startTime>
<endTime>2014-07-09T02:34:50.000Z</endTime>
<listingType>StoreInventory</listingType>
<gift>false</gift>
</listingInfo>
<returnsAccepted>true</returnsAccepted>
<galleryPlusPictureURL>
http://galleryplus.ebayimg.com/ws/web/301209856743_1_0_1.jpg
</galleryPlusPictureURL>
<isMultiVariationListing>false</isMultiVariationListing>
<topRatedListing>false</topRatedListing>
</item>
</searchResult>
<paginationOutput>
<pageNumber>1</pageNumber>
<entriesPerPage>1</entriesPerPage>
<totalPages>111</totalPages>
<totalEntries>111</totalEntries>
</paginationOutput>
<itemSearchURL>
http://www.ebay.com/sch/63/i.html?LH_TitleDesc=1&_nkw=detective+comics+700&_ddo=1&_ipg=1&_pgn=1
</itemSearchURL>
</findItemsAdvancedResponse>

Eu essencialmente quero analisar apenas o título, o preço e talvez o custo de envio.

Pesquisas preliminares indicaram que xmlstarlet é uma escolha sensata para isso, mas não está funcionando (eu sei que devo estar fazendo algo errado).

Quando tento pesquisar, recebo um resultado em branco:

[foouser@foobox fooapp]# cat xmlsample | xmlstarlet sel -t -v "//title"
[foouser@foobox fooapp]#

[foouser@foobox fooapp]# xmlstarlet sel -t -v "//findItemsAdvancedResponse/searchResult/item/title" xmlsample
[foouser@foobox fooapp]#

Alguma idéia de onde eu me perdi?

    

Answer 1

Quando tento reproduzir seus passos, tenho dois problemas:

• EntityRef: expecting ';'

Parece que o documento de origem usa & , onde deve usar & .

Eu consertei isso usando sed -i -e 's/&/&/g' xmlresult .

• None of the XPaths matched; to match a node in the default namespace use '_' as the prefix (see section 5.1 in the manual).

Após a seção 5.1 , tentei adicionar -N services=http://www.ebay.com/marketplace/search/v1/services e colocar services: dentro da consulta XPath e agora eu recebo algo útil.

$ xmlstarlet sel -N services=http://www.ebay.com/marketplace/search/v1/services -t -v '//services:title' result.xml

DETECTIVE COMICS (1937 Series) #700 Near Mint Comics Book