elua: getopt module

diff --git a/src/bin/elua/modules/getopt.lua b/src/bin/elua/modules/getopt.lua
new file mode 100644 (file)
index 0000000..5d848e2
--- /dev/null
+++ b/src/bin/elua/modules/getopt.lua
@@ -0,0 +1,97 @@
+-- Elua getopt module
+
+local M = {}
+
+local hasval_l = function(opt, long)
+    for i, v in ipairs(long) do
+        if v:sub(1, #opt) == opt then
+            local rest = v:sub(#opt + 1)
+            if #rest == 0 then
+                return false, opt
+            elseif rest == "=" then
+                return true, opt
+            end
+        end
+    end
+    error("option --" .. opt .. " not recognized", 4)
+end
+
+local parse_l = function(opts, opt, long, args)
+    local optval
+    local i = opt:find("=")
+    if i then
+        opt, optval = opt:sub(1, i - 1), opt:sub(i + 1)
+    end
+
+    local has_val
+    hasval, opt = hasval_l(opt, long)
+    if hasval then
+        if not optval then
+            if #args == 0 then
+                error("option --" .. opt .. " requires an argument", 3)
+            end
+            optval, args = args[1], { unpack(args, 2) }
+        end
+    elseif optval then
+        error("option --" .. opt .. " cannot have an argument", 3)
+    end
+    opts[#opts + 1] = { "--" .. opt, optval }
+    return opts, args
+end
+
+local hasval_s = function(opt, short)
+    if short:find(opt, 1, true) then
+        return not not short:find(opt .. ":", 1, true)
+    end
+    error("option -" .. opt .. " not recognized", 4)
+end
+
+local parse_s = function(opts, optstr, short, args)
+    while optstr ~= "" do
+        local optval
+        local opt = optstr:sub(1, 1)
+        optstr = optstr:sub(2)
+        if hasval_s(opt, short) then
+            if optstr == "" then
+                if #args == 0 then
+                    error("option -" .. opt .. " requires an argument", 3)
+                end
+                optstr, args = args[1], { unpack(args, 2) }
+            end
+            optval, optstr = optstr, ""
+        end
+        opts[#opts + 1] = { "-" .. opt, optval }
+    end
+    return opts, args
+end
+
+local getopt_u = function(args, short, long)
+    local opts = {}
+    if type(long) == "string" then
+        long = { long }
+    end
+    while args and #args > 0 and args[1]:sub(1, 1) == "-" and args[1] ~= "-" do
+        if args[1] == "--" then
+            args = { unpack(args, 2) }
+            break
+        end
+        if args[1]:sub(1, 2) == "--" then
+            opts, args = parse_l(opts, args[1]:sub(3), long,
+                { unpack(args, 2) })
+        else
+            opts, args = parse_s(opts, args[1]:sub(2), short,
+                { unpack(args, 2) })
+        end
+    end
+    return opts, args
+end
+
+M.getopt = function(args, short, long)
+    local ret, opts, args = pcall(getopt_u, args, short, long)
+    if not ret then
+        return nil, opts
+    end
+    return opts, args
+end
+
+return M
\ No newline at end of file