Merge multiple XML files from command line

Question

I have several xml files. They all have the same structure, but were splitted due to file size. So, let\'s say I have A.xml, B.xml, C.xml

Answer 1

Low-tech simple answer:

echo '<products>' > combined.xml
grep -vh '</\?products>\|<?xml' *.xml >> combined.xml
echo '</products>' >> combined.xml

Limitations:

• The opening and closing tags need to be on their own line.
• The files need to all have the same outer tags.
• The outer tags must not have attributes.
• The files must not have inner tags that match the outer tags.
• Any current contents of combined.xml will be wiped out instead of getting included.

Each of these limitations can be worked around, but not all of them easily.

Answer 2

xml_grep

http://search.cpan.org/dist/XML-Twig/tools/xml_grep/xml_grep

xml_grep --pretty_print indented --wrap products --descr '' --cond "product" *.xml > combined.xml

• --wrap : encloses/wraps the the xml result with the given tag. (here: products)
• --cond : the xml subtree to grep (here: product)

Answer 3

High-tech answer:

Save this Python script as xmlcombine.py:

#!/usr/bin/env python
import sys
from xml.etree import ElementTree

def run(files):
    first = None
    for filename in files:
        data = ElementTree.parse(filename).getroot()
        if first is None:
            first = data
        else:
            first.extend(data)
    if first is not None:
        print ElementTree.tostring(first)

if __name__ == "__main__":
    run(sys.argv[1:])

To combine files, run:

python xmlcombine.py ?.xml > combined.xml

For further enhancement, consider using:

• chmod +x xmlcombine.py: Allows you to omit python in the command line

• xmlcombine.py !(combined).xml > combined.xml: Collects all XML files except the output, but requires bash's extglob option

• xmlcombine.py *.xml | sponge combined.xml: Collects everything in combined.xml as well, but requires the sponge program

• import lxml.etree as ElementTree: Uses a potentially faster XML parser