# Try style "cvs"
Input: ``` $ cat compact.xml <myoutertag one="a" two="b" three="c"> <myinnertag four="d" five="e"/> </myoutertag> ```
Available styles: ``` $ which xml_pp | xargs head -n2 #!/usr/bin/perl -w # $Id: /xmltwig/trunk/tools/xml_pp/xml_pp 32 2008-01-18T13:11:52.128782Z mrodrigu $
$ xml_pp -s help usage: /usr/local/bin/xml_pp [-v] [-i<extension>] [-s (none|nsgmls|nice|indented|indented_close_tag|indented_c|wrapped|record_c|record|cvs|indented_a)] [-p <tag(s)>] [-e <encoding>] [-l] [-f <file>] [<files>] at /usr/local/bin/xml_pp line 100.
$ xml_pp -s help 2>&1 | cut -d"(" -f2 | cut -d")" -f1 | tr "|" "\n" | nl 1 none 2 nsgmls 3 nice 4 indented 5 indented_close_tag 6 indented_c 7 wrapped 8 record_c 9 record 10 cvs 11 indented_a ```
Style "cvs" applied: ``` $ cat compact.xml | xml_pp -s cvs <myoutertag one="a" three="c" two="b"> <myinnertag five="e" four="d" /> </myoutertag> ```

# Try `xml_pp` with style "-s cvs" You asked for something in libxml2. I don't know about that. But if you are willing to use something else, then read on below.
[xml_pp](https://dyn.manpages.debian.org/jump?q=xml_pp) is part of the [XML::Twig](https://metacpan.org/pod/XML::Twig) library and has a bunch of different preconfigured styles.
You can specify a style via the "-s" (style) parameter.
If you just leave "-s" empty, then it will show all available styles. (It actually generate that list on the fly. So it's guaranteed to be fresh.)
``` $ xml_pp -s Use of uninitialized value $opt{"style"} in hash element at /usr/bin/xml_pp line 100. usage: /usr/bin/xml_pp [-v] [-i<extension>] [-s (none|nsgmls|nice|indented|indented_close_tag|indented_c|wrapped|record_c|record|cvs|indented_a)] [-p <tag(s)>] [-e <encoding>] [-l] [-f <file>] [<files>] at /usr/bin/xml_pp line 100. ```
Here's the same thing again but in a nicer list format. It turns out that the version I have installed supports 11 formats out of the box: ``` $ xml_pp -s 2>&1 | grep -Po '(?<=\[-s \()[^)]*' -o | tr '|' '\n' | nl 1 none 2 nsgmls 3 nice 4 indented 5 indented_close_tag 6 indented_c 7 wrapped 8 record_c 9 record 10 cvs 11 indented_a ```
So let's try them all.
This is our input file: ``` $ cat in.xml <a attr="one" bttr="two" tttr="three" fttr="four"/> ```
And these are all the styles: ``` $ for STYLE in $(echo "none nsgmls nice indented indented_close_tag indented_c wrapped record_c record cvs indented_a"); do echo; echo "==> Style: xml_pp -s $STYLE <=="; cat in.xml | xml_pp -s $STYLE | tee out.xml_pp.$STYLE.xml; echo; done
==> Style: xml_pp -s none <== <a attr="one" bttr="two" fttr="four" tttr="three"/>
==> Style: xml_pp -s nsgmls <== <a attr="one" bttr="two" fttr="four" tttr="three" />
==> Style: xml_pp -s nice <== <a attr="one" bttr="two" fttr="four" tttr="three"/>
==> Style: xml_pp -s indented <== <a attr="one" bttr="two" fttr="four" tttr="three"/>
==> Style: xml_pp -s indented_close_tag <== <a attr="one" bttr="two" fttr="four" tttr="three"/>
==> Style: xml_pp -s indented_c <== <a attr="one" bttr="two" fttr="four" tttr="three"/>
==> Style: xml_pp -s wrapped <== <a attr="one" bttr="two" fttr="four" tttr="three"/>
==> Style: xml_pp -s record_c <==
<a attr="one" bttr="two" fttr="four" tttr="three"/>
==> Style: xml_pp -s record <==
<a attr="one" bttr="two" fttr="four" tttr="three"/>
==> Style: xml_pp -s cvs <== <a attr="one" bttr="two" fttr="four" tttr="three" />
==> Style: xml_pp -s indented_a <== <a attr="one" bttr="two" fttr="four" tttr="three" /> ```
A bunch of these styles are equivalent for this small input file. They produce the same output: ``` $ sha256sum * | sort 452f5c19177d9cc6a54589168dbb1ee790c783a963110662e7dfae170bf997e4 out.xml_pp.cvs.xml 452f5c19177d9cc6a54589168dbb1ee790c783a963110662e7dfae170bf997e4 out.xml_pp.indented_a.xml 8e119bb50bcbf3d72159c96139cf328f46a0de259410acdd344f26e52f033996 out.xml_pp.nsgmls.xml d1ed9a4d1ebf8b9f1d012577809909e91e1ba0fc01b5afc8ff1302ca9dced617 out.xml_pp.record_c.xml d1ed9a4d1ebf8b9f1d012577809909e91e1ba0fc01b5afc8ff1302ca9dced617 out.xml_pp.record.xml e0d13f80ddc48876678c62e407abd3ab1eac8481a82d5aabb1514e24aee4717c in.xml ea90003eab0ba71936a8a329a87b079b4fb120fe6873d4fa9bc8f986e8654b45 out.xml_pp.indented_close_tag.xml ea90003eab0ba71936a8a329a87b079b4fb120fe6873d4fa9bc8f986e8654b45 out.xml_pp.indented_c.xml ea90003eab0ba71936a8a329a87b079b4fb120fe6873d4fa9bc8f986e8654b45 out.xml_pp.indented.xml ea90003eab0ba71936a8a329a87b079b4fb120fe6873d4fa9bc8f986e8654b45 out.xml_pp.nice.xml ea90003eab0ba71936a8a329a87b079b4fb120fe6873d4fa9bc8f986e8654b45 out.xml_pp.none.xml ea90003eab0ba71936a8a329a87b079b4fb120fe6873d4fa9bc8f986e8654b45 out.xml_pp.wrapped.xml ```
None of these style are exactly what you wanted.
But "cvs" is pretty close. (And "indented_a" produces identical output.)

# Afterthoughts: bit dirty Afterthoughts: Output feels a little dirty.
(a) Some of the files just start with a blank line for no good reason... ``` $ grep '^$' * -n out.xml_pp.record_c.xml:1: out.xml_pp.record.xml:1: ```
(b) ... and some of the files just have no line terminators at all: ``` $ file * in.xml: ASCII text out.xml_pp.cvs.xml: ASCII text out.xml_pp.indented_a.xml: ASCII text out.xml_pp.indented_close_tag.xml: ASCII text, with no line terminators out.xml_pp.indented_c.xml: ASCII text, with no line terminators out.xml_pp.indented.xml: ASCII text, with no line terminators out.xml_pp.nice.xml: ASCII text, with no line terminators out.xml_pp.none.xml: ASCII text, with no line terminators out.xml_pp.nsgmls.xml: ASCII text out.xml_pp.record_c.xml: ASCII text out.xml_pp.record.xml: ASCII text out.xml_pp.wrapped.xml: ASCII text, with no line terminators ```
-- The thing seems to be that xml_pp does not add a trailing newline after the last line. So if you only have ONE line then there will be no newline byte in there. Quite weird.
Looks like this: ``` $ wc --lines * 5 out.xml_pp.cvs.xml 5 out.xml_pp.indented_a.xml 0 out.xml_pp.indented_close_tag.xml 0 out.xml_pp.indented_c.xml 0 out.xml_pp.indented.xml 0 out.xml_pp.nice.xml 0 out.xml_pp.none.xml 5 out.xml_pp.nsgmls.xml 1 out.xml_pp.record_c.xml 1 out.xml_pp.record.xml 0 out.xml_pp.wrapped.xml 17 total ```
This here is how I like to add a trailing LF (0x0A byte) if none is present: ``` $ mkdir 1; mv out.*.xml 1/; cp -r 1/ 2/
$ pcregrep -LMr '\n\Z' 2/ | xargs -n1 --no-run-if-empty -- sed -i -e '$a\' --
$ diff --recursive 1/ 2/ | head diff --recursive 1/out.xml_pp.cvs.xml 2/out.xml_pp.cvs.xml 6c6 < /> \ No newline at end of file --- > /> diff --recursive 1/out.xml_pp.indented_a.xml 2/out.xml_pp.indented_a.xml 6c6 < /> \ No newline at end of file ```
Looks like this afterwards: ``` $ cd 2/
$ wc --lines * 6 out.xml_pp.cvs.xml 6 out.xml_pp.indented_a.xml 1 out.xml_pp.indented_close_tag.xml 1 out.xml_pp.indented_c.xml 1 out.xml_pp.indented.xml 1 out.xml_pp.nice.xml 1 out.xml_pp.none.xml 6 out.xml_pp.nsgmls.xml 2 out.xml_pp.record_c.xml 2 out.xml_pp.record.xml 1 out.xml_pp.wrapped.xml 28 total ```