testing version of LuaBIOS and OpenOS

people were having issues getting them to work so now we promote consistency

data/OpenOS/lib/shell.lua

@@ -0,0 +1,144 @@
+local fs = require("filesystem")
+local unicode = require("unicode")
+local process = require("process")
+
+local shell = {}
+
+-- Cache loaded shells for command execution. This puts the requirement on
+-- shells that they do not keep a global state, since they may be called
+-- multiple times, but reduces memory usage a lot.
+local shells = setmetatable({}, {__mode="v"})
+
+function shell.getShell()
+  local shellPath = os.getenv("SHELL") or "/bin/sh"
+  local shellName, reason = shell.resolve(shellPath, "lua")
+  if not shellName then
+    return nil, "cannot resolve shell `" .. shellPath .. "': " .. reason
+  end
+  if shells[shellName] then
+    return shells[shellName]
+  end
+  local sh, load_reason = loadfile(shellName, nil, setmetatable({}, {__index=_G}))
+  if sh then
+    shells[shellName] = sh
+  end
+  return sh, load_reason
+end
+
+-------------------------------------------------------------------------------
+
+function shell.prime()
+  local data = process.info().data
+  for _,key in ipairs({'aliases','vars'}) do
+    -- first time get need to populate
+    local raw = rawget(data, key)
+    if not raw then
+      -- current process does not have the key
+      local current = data[key]
+      data[key] = {}
+      if current then
+        for k,v in pairs(current) do
+          data[key][k] = v
+        end
+      end
+    end
+  end
+end
+
+function shell.getAlias(alias)
+  return process.info().data.aliases[alias]
+end
+
+function shell.setAlias(alias, value)
+  checkArg(1, alias, "string")
+  checkArg(2, value, "string", "nil")
+  process.info().data.aliases[alias] = value
+end
+
+function shell.getWorkingDirectory()
+  -- if no env PWD default to /
+  return os.getenv("PWD") or "/"
+end
+
+function shell.setWorkingDirectory(dir)
+  checkArg(1, dir, "string")
+  -- ensure at least /
+  -- and remove trailing /
+  dir = fs.canonical(dir):gsub("^$", "/"):gsub("(.)/$", "%1")
+  if fs.isDirectory(dir) then
+    os.setenv("PWD", dir)
+    return true
+  else
+    return nil, "not a directory"
+  end
+end
+
+function shell.resolve(path, ext)
+  checkArg(1, path, "string")
+
+  local dir = path
+  if dir:find("/") ~= 1 then
+    dir = fs.concat(shell.getWorkingDirectory(), dir)
+  end
+  local name = fs.name(path)
+  dir = fs[name and "path" or "canonical"](dir)
+  local fullname = fs.concat(dir, name or "")
+
+  if not ext then
+    return fullname
+  elseif name then
+    checkArg(2, ext, "string")
+    -- search for name in PATH if no dir was given
+    -- no dir was given if path has no /
+    local search_in = path:find("/") and dir or os.getenv("PATH")
+    for search_path in string.gmatch(search_in, "[^:]+") do
+      -- resolve search_path because they may be relative
+      local search_name = fs.concat(shell.resolve(search_path), name)
+      if not fs.exists(search_name) then
+        search_name = search_name .. "." .. ext
+      end
+      -- extensions are provided when the caller is looking for a file
+      if fs.exists(search_name) and not fs.isDirectory(search_name) then
+        return search_name
+      end
+    end
+  end
+
+  return nil, "file not found"
+end
+
+function shell.parse(...)
+  local params = table.pack(...)
+  local args = {}
+  local options = {}
+  local doneWithOptions = false
+  for i = 1, params.n do
+    local param = params[i]
+    if not doneWithOptions and type(param) == "string" then
+      if param == "--" then
+        doneWithOptions = true -- stop processing options at `--`
+      elseif param:sub(1, 2) == "--" then
+        local key, value = param:match("%-%-(.-)=(.*)")
+        if not key then
+          key, value = param:sub(3), true
+        end
+        options[key] = value
+      elseif param:sub(1, 1) == "-" and param ~= "-" then
+        for j = 2, unicode.len(param) do
+          options[unicode.sub(param, j, j)] = true
+        end
+      else
+        table.insert(args, param)
+      end
+    else
+      table.insert(args, param)
+    end
+  end
+  return args, options
+end
+
+-------------------------------------------------------------------------------
+
+require("package").delay(shell, "/lib/core/full_shell.lua")
+
+return shell