NetBSD/libexec/httpd/lua/optparse.lua

124 lines
3.9 KiB
Lua

-- Lua command line option parser.
-- Interface based on Pythons optparse.
-- http://docs.python.org/lib/module-optparse.html
-- (c) 2008 David Manura, Licensed under the same terms as Lua (MIT license)
--
-- To be used like this:
-- t={usage="<some usage message>", version="<version string>"}
-- op=OptionParser(t)
-- op=add_option{"<opt>", action=<action>, dest=<dest>, help="<help message for this option>"}
--
-- with :
-- <opt> the option string to be used (can be anything, if one letter opt, then should be -x val, more letters: -xy=val )
-- <action> one of
-- - store: store in options as key, val
-- - store_true: stores key, true
-- - store_false: stores key, false
-- <dest> is the key under which the option is saved
--
-- options,args = op.parse_args()
--
-- now options is the table of options (key, val) and args is the table with non-option arguments.
-- You can use op.fail(message) for failing and op.print_help() for printing the usage as you like.
function OptionParser(t)
local usage = t.usage
local version = t.version
local o = {}
local option_descriptions = {}
local option_of = {}
function o.fail(s) -- extension
io.stderr:write(s .. '\n')
os.exit(1)
end
function o.add_option(optdesc)
option_descriptions[#option_descriptions+1] = optdesc
for _,v in ipairs(optdesc) do
option_of[v] = optdesc
end
end
function o.parse_args()
-- expand options (e.g. "--input=file" -> "--input", "file")
local arg = {unpack(arg)}
for i=#arg,1,-1 do local v = arg[i]
local flag, val = v:match('^(%-%-%w+)=(.*)')
if flag then
arg[i] = flag
table.insert(arg, i+1, val)
end
end
local options = {}
local args = {}
local i = 1
while i <= #arg do local v = arg[i]
local optdesc = option_of[v]
if optdesc then
local action = optdesc.action
local val
if action == 'store' or action == nil then
i = i + 1
val = arg[i]
if not val then o.fail('option requires an argument ' .. v) end
elseif action == 'store_true' then
val = true
elseif action == 'store_false' then
val = false
end
options[optdesc.dest] = val
else
if v:match('^%-') then o.fail('invalid option ' .. v) end
args[#args+1] = v
end
i = i + 1
end
if options.help then
o.print_help()
os.exit()
end
if options.version then
io.stdout:write(t.version .. "\n")
os.exit()
end
return options, args
end
local function flags_str(optdesc)
local sflags = {}
local action = optdesc.action
for _,flag in ipairs(optdesc) do
local sflagend
if action == nil or action == 'store' then
local metavar = optdesc.metavar or optdesc.dest:upper()
sflagend = #flag == 2 and ' ' .. metavar
or '=' .. metavar
else
sflagend = ''
end
sflags[#sflags+1] = flag .. sflagend
end
return table.concat(sflags, ', ')
end
function o.print_help()
io.stdout:write("Usage: " .. usage:gsub('%%prog', arg[0]) .. "\n")
io.stdout:write("\n")
io.stdout:write("Options:\n")
for _,optdesc in ipairs(option_descriptions) do
io.stdout:write(" " .. flags_str(optdesc) ..
" " .. optdesc.help .. "\n")
end
end
o.add_option{"--help", action="store_true", dest="help",
help="show this help message and exit"}
if t.version then
o.add_option{"--version", action="store_true", dest="version",
help="output version info."}
end
return o
end