xml_split - cut a big XML file into smaller chunks
"xml_split" takes a (presumably big) XML file and split it in several
smaller files. The memory used is the memory needed for the biggest chunk (ie
memory is reused for each new chunk).
It can split at a given level in the tree (the default, splits children of the
root), or on a condition (using the subset of XPath understood by XML::Twig,
so "section" or "/doc/section").
Each generated file is replaced by a processing instruction that will allow
"xml_merge" to rebuild the original document. The processing
instruction format is "<?merge subdocs= :<filename>
File names are <file>-<nb>.xml, with <file>-00.xml holding the
- -l <level>
- level to cut at: 1 generates a file for each child of the root, 2 for each
defaults to 1
- -c <condition>
- generate a file for each element that passes the condition
xml_split -c <section> will put each "section" element in
its own file (nested sections are handled too)
Note that at the moment this option is a lot slower than using
- -s <size>
- generates files of (approximately) <size>. The content of each file
is enclosed in a new element ("xml_split::root"), so it's
well-formed XML. The size can be given in bytes, Kb, Mb or Gb.
- -g <nb>
- groups <nb> elements in a single file. The content of each file is
enclosed in a new element ("xml_split::root"), so it's
- -b <name>
- base name for the output, files will be named
<nb> is a sequence number, see below "--nb_digits"
<ext> is an extension, see below "--extension"
defaults to the original file name (if available) or "out" (if
input comes from the standard input)
- -n <nb>
- number of digits in the sequence number for each file
if more digits than <nb> are needed, then they are used: if
"--nb_digits 2" is used and 112 files are generated they will be
named "<file>-01.xml" to "<file>-112.xml"
defaults to 2
- -e <ext>
- extension to use for generated files
defaults to the original file extension or ".xml"
- use XInclude elements instead of Processing Instructions to mark where sub
files need to be included
- verbose output
Note that this option can slow down processing considerably (by an order of
magnitude) when generating lots of small documents
- outputs version and exit
- short help
- man (requires pod2text to be in the path)
xml_split foo.xml # split at level 1
xml_split -l 2 foo.xml # split at level 2
xml_split -c section foo.xml # a file is generated for each section element
# nested sections are split properly
- optimize the code
- any idea welcome! I have already implemented most of what I thought would
- provide other methods that PIs to keep merge information
- XInclude is a good candidate (alpha support added in 0.04).
using entities, which would seem the natural way to do it, doesn't work, as
they make it impossible to have both the main document and the sub docs to
be well-formed if the sub docs include sub-sub docs (you can't have entity
declarations in an entity)
Michel Rodriguez <email@example.com>
This tool is free software; you can redistribute it and/or modify it under the
same terms as Perl itself.