refactor parallel code

openos/rm.lua

@@ -0,0 +1,158 @@
+local fs = require("filesystem")
+local shell = require("shell")
+
+local function usage()
+  print("Usage: rm [options] <filename1> [<filename2> [...]]"..[[
+
+  -f          ignore nonexistent files and arguments, never prompt
+  -r          remove directories and their contents recursively
+  -v          explain what is being done
+      --help  display this help and exit
+
+For complete documentation and more options, run: man rm]])
+end
+
+local args, options = shell.parse(...)
+if #args == 0 or options.help then
+  usage()
+  return 1
+end
+
+local bRec = options.r or options.R or options.recursive
+local bForce = options.f or options.force
+local bVerbose = options.v or options.verbose
+local bEmptyDirs = options.d or options.dir
+local promptLevel = (options.I and 3) or (options.i and 1) or 0
+
+bVerbose = bVerbose and not bForce
+promptLevel = bForce and 0 or promptLevel
+
+local function perr(...)
+  if not bForce then
+    io.stderr:write(...)
+  end
+end
+
+local function pout(...)
+  if not bForce then
+    io.stdout:write(...)
+  end
+end
+
+local metas = {}
+
+-- promptLevel 3 done before fs.exists
+-- promptLevel 1 asks for each, displaying fs.exists on hit as it visits
+
+local function _path(m) return shell.resolve(m.rel) end
+local function _link(m) return fs.isLink(_path(m)) end
+local function _exists(m) return _link(m) or fs.exists(_path(m)) end
+local function _dir(m) return not _link(m) and fs.isDirectory(_path(m)) end
+local function _readonly(m) return not _exists(m) or fs.get(_path(m)).isReadOnly() end
+local function _empty(m) return _exists(m) and _dir(m) and (fs.list(_path(m))==nil) end
+
+local function createMeta(origin, rel)
+  local m = {origin=origin,rel=rel:gsub("/+$", "")}
+  if _dir(m) then
+    m.rel = m.rel .. '/'
+  end
+  return m
+end
+
+local function unlink(path)
+  os.remove(path)
+  return true
+end
+
+local function confirm()
+  if bForce then
+    return true
+  end
+  local r = io.read()
+  return r == 'y' or r == 'yes'
+end
+
+local function remove_all(parent)
+  if parent == nil or not _dir(parent) or _empty(parent) then
+    return true
+  end
+
+  local all_ok = true
+  if bRec and promptLevel == 1 then
+    pout(string.format("rm: descend into directory `%s'? ", parent.rel))
+    if not confirm() then
+      return false
+    end
+
+    for file in fs.list(_path(parent)) do
+      local child = createMeta(parent.origin, parent.rel .. file)
+      all_ok = remove(child) and all_ok
+    end
+  end
+
+  return all_ok
+end
+
+local function remove(meta)
+  if not remove_all(meta) then
+    return false
+  end
+
+  if not _exists(meta) then
+    perr(string.format("rm: cannot remove `%s': No such file or directory\n", meta.rel))
+    return false
+  elseif _dir(meta) and not bRec and not (_empty(meta) and bEmptyDirs) then
+    if not bEmptyDirs then
+      perr(string.format("rm: cannot remove `%s': Is a directory\n", meta.rel))
+    else
+      perr(string.format("rm: cannot remove `%s': Directory not empty\n", meta.rel))
+    end
+    return false
+  end
+
+  local ok = true
+  if promptLevel == 1 then
+    if _dir(meta) then
+      pout(string.format("rm: remove directory `%s'? ", meta.rel))
+    elseif meta.link then
+      pout(string.format("rm: remove symbolic link `%s'? ", meta.rel))
+    else -- file
+      pout(string.format("rm: remove regular file `%s'? ", meta.rel))
+    end
+
+    ok = confirm()
+  end
+
+  if ok then
+    if _readonly(meta) then
+      perr(string.format("rm: cannot remove `%s': Is read only\n", meta.rel))
+      return false
+    elseif not unlink(_path(meta)) then
+      perr(meta.rel .. ": failed to be removed\n")
+      ok = false
+    elseif bVerbose then
+      pout("removed '" .. meta.rel .. "'\n");
+    end
+  end
+
+  return ok
+end
+
+for _,arg in ipairs(args) do
+  metas[#metas+1] = createMeta(arg, arg)
+end
+
+if promptLevel == 3 and #metas > 3 then
+  pout(string.format("rm: remove %i arguments? ", #metas))
+  if not confirm() then
+    return
+  end
+end
+
+local ok = true
+for _,meta in ipairs(metas) do
+  local result = remove(meta)
+  ok = ok and result
+end
+
+return bForce or ok