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Diffstat (limited to 'Data/Libraries/Penlight/lua/pl/config.lua')
| -rw-r--r-- | Data/Libraries/Penlight/lua/pl/config.lua | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/Data/Libraries/Penlight/lua/pl/config.lua b/Data/Libraries/Penlight/lua/pl/config.lua new file mode 100644 index 0000000..2e6db0c --- /dev/null +++ b/Data/Libraries/Penlight/lua/pl/config.lua @@ -0,0 +1,207 @@ +--- Reads configuration files into a Lua table. +-- Understands INI files, classic Unix config files, and simple +-- delimited columns of values. See @{06-data.md.Reading_Configuration_Files|the Guide} +-- +-- # test.config +-- # Read timeout in seconds +-- read.timeout=10 +-- # Write timeout in seconds +-- write.timeout=5 +-- #acceptable ports +-- ports = 1002,1003,1004 +-- +-- -- readconfig.lua +-- local config = require 'config' +-- local t = config.read 'test.config' +-- print(pretty.write(t)) +-- +-- ### output ##### +-- { +-- ports = { +-- 1002, +-- 1003, +-- 1004 +-- }, +-- write_timeout = 5, +-- read_timeout = 10 +-- } +-- +-- @module pl.config + +local type,tonumber,ipairs,io, table = _G.type,_G.tonumber,_G.ipairs,_G.io,_G.table + +local function split(s,re) + local res = {} + local t_insert = table.insert + re = '[^'..re..']+' + for k in s:gmatch(re) do t_insert(res,k) end + return res +end + +local function strip(s) + return s:gsub('^%s+',''):gsub('%s+$','') +end + +local function strip_quotes (s) + return s:gsub("['\"](.*)['\"]",'%1') +end + +local config = {} + +--- like io.lines(), but allows for lines to be continued with '\'. +-- @param file a file-like object (anything where read() returns the next line) or a filename. +-- Defaults to stardard input. +-- @return an iterator over the lines, or nil +-- @return error 'not a file-like object' or 'file is nil' +function config.lines(file) + local f,openf,err + local line = '' + if type(file) == 'string' then + f,err = io.open(file,'r') + if not f then return nil,err end + openf = true + else + f = file or io.stdin + if not file.read then return nil, 'not a file-like object' end + end + if not f then return nil, 'file is nil' end + return function() + local l = f:read() + while l do + -- only for non-blank lines that don't begin with either ';' or '#' + if l:match '%S' and not l:match '^%s*[;#]' then + -- does the line end with '\'? + local i = l:find '\\%s*$' + if i then -- if so, + line = line..l:sub(1,i-1) + elseif line == '' then + return l + else + l = line..l + line = '' + return l + end + end + l = f:read() + end + if openf then f:close() end + end +end + +--- read a configuration file into a table +-- @param file either a file-like object or a string, which must be a filename +-- @tab[opt] cnfg a configuration table that may contain these fields: +-- +-- * `smart` try to deduce what kind of config file we have (default false) +-- * `variabilize` make names into valid Lua identifiers (default true) +-- * `convert_numbers` try to convert values into numbers (default true) +-- * `trim_space` ensure that there is no starting or trailing whitespace with values (default true) +-- * `trim_quotes` remove quotes from strings (default false) +-- * `list_delim` delimiter to use when separating columns (default ',') +-- * `keysep` separator between key and value pairs (default '=') +-- +-- @return a table containing items, or `nil` +-- @return error message (same as @{config.lines} +function config.read(file,cnfg) + local auto + + local iter,err = config.lines(file) + if not iter then return nil,err end + local line = iter() + cnfg = cnfg or {} + if cnfg.smart then + auto = true + if line:match '^[^=]+=' then + cnfg.keysep = '=' + elseif line:match '^[^:]+:' then + cnfg.keysep = ':' + cnfg.list_delim = ':' + elseif line:match '^%S+%s+' then + cnfg.keysep = ' ' + -- more than two columns assume that it's a space-delimited list + -- cf /etc/fstab with /etc/ssh/ssh_config + if line:match '^%S+%s+%S+%s+%S+' then + cnfg.list_delim = ' ' + end + cnfg.variabilize = false + end + end + + + local function check_cnfg (var,def) + local val = cnfg[var] + if val == nil then return def else return val end + end + + local initial_digits = '^[%d%+%-]' + local t = {} + local top_t = t + local variabilize = check_cnfg ('variabilize',true) + local list_delim = check_cnfg('list_delim',',') + local convert_numbers = check_cnfg('convert_numbers',true) + local convert_boolean = check_cnfg('convert_boolean',false) + local trim_space = check_cnfg('trim_space',true) + local trim_quotes = check_cnfg('trim_quotes',false) + local ignore_assign = check_cnfg('ignore_assign',false) + local keysep = check_cnfg('keysep','=') + local keypat = keysep == ' ' and '%s+' or '%s*'..keysep..'%s*' + if list_delim == ' ' then list_delim = '%s+' end + + local function process_name(key) + if variabilize then + key = key:gsub('[^%w]','_') + end + return key + end + + local function process_value(value) + if list_delim and value:find(list_delim) then + value = split(value,list_delim) + for i,v in ipairs(value) do + value[i] = process_value(v) + end + elseif convert_numbers and value:find(initial_digits) then + local val = tonumber(value) + if not val and value:match ' kB$' then + value = value:gsub(' kB','') + val = tonumber(value) + end + if val then value = val end + elseif convert_boolean and value == 'true' then + return true + elseif convert_boolean and value == 'false' then + return false + end + if type(value) == 'string' then + if trim_space then value = strip(value) end + if not trim_quotes and auto and value:match '^"' then + trim_quotes = true + end + if trim_quotes then value = strip_quotes(value) end + end + return value + end + + while line do + if line:find('^%[') then -- section! + local section = process_name(line:match('%[([^%]]+)%]')) + t = top_t + t[section] = {} + t = t[section] + else + line = line:gsub('^%s*','') + local i1,i2 = line:find(keypat) + if i1 and not ignore_assign then -- key,value assignment + local key = process_name(line:sub(1,i1-1)) + local value = process_value(line:sub(i2+1)) + t[key] = value + else -- a plain list of values... + t[#t+1] = process_value(line) + end + end + line = iter() + end + return top_t +end + +return config |