Replace only within a XML tag; exporting from Referencer .reflib to bibtex format with filenames intact and URL-encoding removed, with a bash command

I have many references in Referencer. I'm trying to include filenames in my bibtex file when exporting from Referencer. Since the software doesn't do this by default I'm trying to use a sed command to include the filename as a bibtex information in the XML file before I export and thus include the filename.

Input

  <doc>
<filename>file:///home/dwickrama/Desktop/stevenJonesLab/papers/Transcription%20Factor%20Binding/A%20Common%20Nuclear%20Signal%20Transduction%20Pathway%20Activated%20by%20Growth%20Factor%20and%20Cytokine.pdf</filename>
<relative_filename>A%20Common%20Nuclear%20Signal%20Transduction%20Pathway%20Activated%20by%20Growth%20Factor%20and%20Cytokine.pdf</relative_filename>
<key>Sadowski93</key>
<notes></notes>
<bib_type>article</bib_type>
<bib_doi></bib_doi>
<bib_title>A common nuclear signal transduction pathway activated by growth factor and cytokine receptors.</bib_title>
<bib_authors>Sadowski, H B and Shuai, K and Darnell, J E and Gilman, M Z</bib_authors>
<bib_journal>Science</bib_journal>
<bib_volume>261</bib_volume>
<bib_number>5129</bib_number>
<bib_pages>1739-44</bib_pages>
<bib_year>1993</bib_year>
<bib_extra key="pmid">8397445</bib_extra>

Ouput

  <doc>
<filename>file:///home/dwickrama/Desktop/stevenJonesLab/papers/Transcription%20Factor%20Binding/A%20Common%20Nuclear%20Signal%20Transductio开发者_StackOverflown%20Pathway%20Activated%20by%20Growth%20Factor%20and%20Cytokine.pdf</filename>
<bib_extra key="File">article:../Transcription\ Factor\ Binding/A\ Common\ Nuclear\ Signal\ Transduction\ Pathway\ Activated\ by\ Growth\ Factor\ and\ Cytokine.pdf:pdf</bib_extra>
<relative_filename>A%20Common%20Nuclear%20Signal%20Transduction%20Pathway%20Activated%20by%20Growth%20Factor%20and%20Cytokine.pdf</relative_filename>
<key>Sadowski93</key>
<notes></notes>
<bib_type>article</bib_type>
<bib_doi></bib_doi>
<bib_title>A common nuclear signal transduction pathway activated by growth factor and cytokine receptors.</bib_title>
<bib_authors>Sadowski, H B and Shuai, K and Darnell, J E and Gilman, M Z</bib_authors>
<bib_journal>Science</bib_journal>
<bib_volume>261</bib_volume>
<bib_number>5129</bib_number>
<bib_pages>1739-44</bib_pages>
<bib_year>1993</bib_year>
<bib_extra key="pmid">8397445</bib_extra>

I can use the following sed command to partially do what I want, but the URL encoding "%20" remains. How do I get rid of that in only the bibtex tag ?

sed -e 's/\(\ \ \ \ <filename>file:\/\/\/home\/dwickrama\/Desktop\/stevenJonesLab\/papers\)\([^.]*\)\(\.\?\)\(.*\)\(<\/filename>\)/\1\2\3\4\5\n\ \ \ \ <bib_extra\ key=\"File\">article:\.\.\2\3\4:\4<\/bib_extra>/g' NewPapers.reflib > NewPapers.new.reflib

Regex and sed are not very good tools for processing XML, or URL-decoding.

A quick script in more complete scripting language would be able to do it more clearly and reliably. For example in Python:

import urllib, urlparse
from xml.dom import minidom

doc= minidom.parse('NewPapers.reflib')
el= doc.getElementsByTagName('filename')[0]
path= urlparse.urlparse(el.firstChild.data)[2]
foldername, filename= map(urllib.unquote, path.split('/')[-2:])

extra= doc.createElement('bib_extra')
extra.setAttribute('key', 'File')
extra.appendChild(document.createTextNode('article:../%s/%s:pdf' % (foldername, filename)))
el.parentNode.insertBefore(extra, el.nextSibling)
doc.writexml(open('NewPapers.new.reflib'))

(I haven't included a function to reproduce the backslash-escaping in the given example output as it's not clearly exactly what format that is. The simplest approach would be filename= filename.replace(' ', '\\ '), but I'm not sure that would be correct.)

all you need is to add a line after right?? So just print it out after is searched.

#!/bin/bash

s='<bib_extra key="File">article:../Transcription\\ Factor\\ Binding/A\\ Common\\ Nuclear\\ Signal\\ Transduction\\ Pathway\\ Activated\\ by\\ Growth\\ Factor\\ and\\ Cytokine.pdf:pdf</bib_extra>'

awk -vstr="$s" '
/<filename>/{
    print
    print str;next
}
{print}' file