How can I extract URLs from JSON data?

I've a text document from which I want to extract URLs and place them in a new text file. How can I do that in Perl? A sample of the text file is here:

{"type":"TabGroupsManager:GroupData","id":65,"name":"XML Schema Editor","image":"http://www.altova.com/favicon.ico","disableAutoRename":false,"titleList":"XML Schema Editor\u000aAltova XMLSpy Code Generation\u000aOnline Video Demos\u000aScheduled Data Exchange Case Study\u000aXML Editor\u000aAltova XMLSpy 2011\u000aXML Schema Management Tool\u000a","tabs":["{\"entries\":[{\"url\":\"http://www.altova.com/xmlspy/xml-schema-editor.html\",\"title\":\"XML Schema Editor\",\"ID\":1442422751,\"referrer\":\"http://www.altova.com/xmlspy/xml-editing.html\",\"scroll\":\"0,0\",\"formdata\":{\"#q\":\"\"}}],\"index\":1,\"attributes\":{\"image\":\"http://www.altova.com/favicon.ico\"},\"extData\":{\"TabGroupsManagerGroupId\":\"65\",\"TabGroupsManagerGroupName\":\"XML Schema Editor\"},\"_formDataSaved\":true}","{\"entries\":[{\"url\":\"http://www.altova.com/xmlspy/xml-code-generation.html\",\"title\":\"Altova XMLSpy Code Generation\",\"ID\":1442423118,\"referrer\":\"http://www.google.com/search?hl=en&client=firefox-a&hs=GR1&rls=org.mozilla%3Aen-GB%3Aofficial&q=altova+derive+schema+from+xml&aq=f&aqi=m1&aql=&oq=&gs_rfai=\",\"scroll\":\"0,0\",\"formdata\":{\"#q\":\"\"}}],\"index\":1,\"attributes\":{\"image\":\"http://www.altova.com/favicon.ico\"},\"extData\":{\"TabGroupsManagerGroupId\":\"65\",\"TabGroupsManagerGroupName\":\"XML Schema Editor\"},\"_formDataSaved\":true}","{\"entries\":[{\"url\":\"http://www.altova.com/videos.asp?type=0&video=xmlspy\",\"title\":\"Online Video Demos\",\"ID\":1442423184,\"referrer\":\"http://www.altova.com/xmlspy/xml-code-generation.html\",\"scroll\":\"0,0\",\"formdata\":{\"#q\":\"\"}}],\"index\":1,\"attributes\":{\"image\":\"http://www.altova.com/favicon.ico\"},\"extData\":{\"TabGroupsManagerGroupId\":\"65\",\"TabGroupsManagerGroupName\":\"XML Schema Editor\"},\"_formDataSaved\":true}","{\"entries\":[{\"url\":\"http://www.altova.com/solutions/exchange_ratecasestudy.html\",\"title\":\"Scheduled Data Exchange Case Study\",\"ID\":2618,\"formdata\":{\"#q\":\"\"},\"scroll\":\"0,1369\"}],\"index\":1,\"attributes\":{\"image\":\"http://www.altova.com/favicon.ico\"},\"extData\":{\"TabGroupsManagerGroupId\":\"65\",\"TabGroupsManagerGroupName\":\"XML Schema Editor\"},\"_formDataSaved\":true}","{\"entries\":[{\"url\":\"http://www.altova.com/xml-editor/\",\"title\":\"XML Editor\",\"ID\":2620,\"formdata\":{\"#q\":\"\"},\"scroll\":\"0,0\"}],\"index\":1,\"attributes\":{\"image\":\"http://www.altova.com/favicon.ico\"},\"extData\":{\"TabGroupsManagerGroupId\":\"65\",\"TabGroupsManagerGroupName\":\"XML Schema Editor\"},\"_formDataSaved\":true}","{\"entries\":[{\"url\":\"http://manual.altova.com/XMLSpy/spystandard/index.html?xmlschemasstd.htm\",\"title\":\"Altova XMLSpy 2011\",\"ID\":2622,\"children\":[{\"url\":\"http://manual.altova.com/XMLSpy/spystandard/xmlspy_co开发者_如何学Pythonntent_dyn.html\",\"title\":\"Altova XMLSpy 2011\",\"ID\":2623,\"referrer\":\"http://manual.altova.com/XMLSpy/spystandard/index.html?xmlschemasstd.htm\",\"scroll\":\"0,0\"},{\"url\":\"http://manual.altova.com/XMLSpy/spystandard/xmlschemasstd.htm\",\"title\":\"XML Schemas\",\"ID\":2624,\"referrer\":\"http://manual.altova.com/XMLSpy/spystandard/index.html?xmlschemasstd.htm\",\"scroll\":\"0,260\"}],\"scroll\":\"0,0\"}],\"index\":1,\"attributes\":{},\"extData\":{\"TabGroupsManagerGroupId\":\"65\",\"TabGroupsManagerGroupName\":\"XML Schema Editor\"},\"_formDataSaved\":true}","{\"entries\":[{\"url\":\"http://www.altova.com/schemaagent.html\",\"title\":\"XML Schema Management Tool\",\"ID\":2626,\"formdata\":{\"#q\":\"\"},\"scroll\":\"0,171\"}],\"index\":1,\"attributes\":{\"image\":\"http://www.altova.com/favicon.ico\"},\"extData\":{\"TabGroupsManagerGroupId\":\"65\",\"TabGroupsManagerGroupName\":\"XML Schema Editor\"},\"_formDataSaved\":true}"]}

From that I want to create a text file like:

http://www.altova.com/xmlspy/xml-schema-editor.html
http://www.altova.com/xmlspy/xml-code-generation.html

Since that appears to be a JSON file rather than a plain text file, use one of the JSON modules on CPAN. This is slightly complicated by the fact that you appear to have data encoded as JSON then stored as strings in a larger object which has then been converted to JSON — so you will have to parse the file, extract the strings, parse them as JSON in turn and then extract the URIs from them.

if Perl is not a must ,

$ sed 's|\\||g' file| awk -vRS='"url":' -F"," '{print $1}' | grep -E "http|ftp"
"http://www.altova.com/xmlspy/xml-schema-editor.html"
"http://www.altova.com/xmlspy/xml-code-generation.html"
"http://www.altova.com/videos.asp?type=0&video=xmlspy"
"http://www.altova.com/solutions/exchange_ratecasestudy.html"
"http://www.altova.com/xml-editor/"
"http://manual.altova.com/XMLSpy/spystandard/index.html?xmlschemasstd.htm"
"http://manual.altova.com/XMLSpy/spystandard/xmlspy_content_dyn.html"
"http://manual.altova.com/XMLSpy/spystandard/xmlschemasstd.htm"
"http://www.altova.com/schemaagent.html"