Some ambiguity (e.g., same-named man pages in multiple volumes)
makes it impossible to fully automate this, but the following
Python snippet (run inside the man/ directory of the systemd repo)
helped to generate the sed command lines (which were subsequently
manually reviewed, run and the false positives reverted):
from pathlib import Path
import lxml
from lxml import etree as ET
man2vol: dict[str, str] = {}
man2citerefs: dict[str, list] = {}
for file in Path(".").glob("*.xml"):
tree = ET.parse(file, lxml.etree.XMLParser(recover=True))
meta = tree.find("refmeta")
if meta is not None:
title = meta.findtext("refentrytitle")
if title is not None:
vol = meta.findtext("manvolnum")
if vol is not None:
man2vol[title] = vol
citerefs = list(tree.iter("citerefentry"))
if citerefs:
man2citerefs[title] = citerefs
for man, refs in man2citerefs.items():
for ref in refs:
title = ref.findtext("refentrytitle")
if title is not None:
has = ref.findtext("manvolnum")
try:
should_have = man2vol[title]
except KeyError: # Non-systemd man page reference? Ignore.
continue
if has != should_have:
print(
f"sed -i '\\|<citerefentry><refentrytitle>{title}"
f"</refentrytitle><manvolnum>{has}</manvolnum>"
f"</citerefentry>|s|<manvolnum>{has}</manvolnum>|"
f"<manvolnum>{should_have}</manvolnum>|' {man}.xml"
)
This tries to add information about when each option was added. It goes
back to version 183.
The version info is included from a separate file to allow generating it,
which would allow more control on the formatting of the final output.