Bibgen

bibgen.lua

-- invoke as: lua bibgen.lua master.bib paper1.tex paper2.mybib paper3.cites ...
-- a ".tex" or ".latex" file will be parsed for \cite{name} entries
-- anything else will be treated as a newline-separated list of paper names
-- the output file will be the name of the input file, with the extension replaced with ".bib"
-- note: will overwrite files without prompting. Handle with care.

-- parse a BibTeX file into a table of entries indexed by name
local function parsebib(buf)
  local bib = {}
  
  -- each entry is of the form @<type>{name, key=value, key=value, ...}
  for entry in buf:gmatch('@%w+%b{}') do
    local name = entry:match('{%s*([^,]+)')
    bib[name] = entry
  end
  
  return bib
end

-- scan a TeX or LaTeX file for \cites
local function parseTeX(buf)
  local iter = buf:gmatch([[\cite(%b{})]])
  return function() for cite in iter do return cite:sub(2,-2) end end
end

local function genbib(bib, file)
  local cites
  local ofname = file:gsub("%.[^%.]*$", ".bib")
  local fout = assert(io.open(ofname, "w"))
  
  print("Generating " .. ofname .. " from " .. file)
  
  if file:match("%.tex$") or file:match("%.latex$") then
    local buf = assert(io.open(file, "r")):read("*a")
    cites = parseTeX(buf)
  else
    cites = io.lines(file)
  end
  
  for cite in cites do
    if bib[cite] then
      fout:write(bib[cite] .. "\n\n")
    else
      print("", "WARNING: cite '" .. cite .. "' not found in master file.")
    end
  end
  
  fout:close()
end   

print("Loading " .. arg[1] .. "...")
local bib = parsebib(assert(io.open(arg[1], "r")):read("*a"))
for name in pairs(bib) do print("", name) end

for i=2,#arg do
  genbib(bib, arg[i])
end