forgot to commit openos

data/openos/bin/alias.lua

@@ -0,0 +1,62 @@
+local shell = require("shell")
+local args, options = shell.parse(...)
+
+local ec, error_prefix = 0, "alias:"
+
+if options.help then
+  print(string.format("Usage: alias: [name[=value] ... ]"))
+  return
+end
+
+local function validAliasName(k)
+  return k:match("[/%$`=|&;%(%)<> \t]") == nil
+end
+
+local function setAlias(k, v)
+  if not validAliasName(k) then
+    io.stderr:write(string.format("%s `%s': invalid alias name\n", error_prefix, k))
+  else
+    shell.setAlias(k, v)
+  end
+end
+
+local function printAlias(k)
+  local v = shell.getAlias(k)
+  if not v then
+    io.stderr:write(string.format("%s %s: not found\n", error_prefix, k))
+    ec = 1
+  else
+    io.write(string.format("alias %s='%s'\n", k, v))
+  end
+end
+
+local function splitPair(arg)
+  local matchBegin, matchEnd = arg:find("=")
+  if matchBegin == nil or matchBegin == 1 then
+    return arg
+  else
+    return arg:sub(1, matchBegin - 1), arg:sub(matchEnd + 1)
+  end
+end
+
+local function handlePair(k, v)
+  if v then
+    return setAlias(k, v)
+  else
+    return printAlias(k)
+  end
+end
+
+if not next(args) then -- no args
+  -- print all aliases
+  for k,v in shell.aliases() do
+    print(string.format("alias %s='%s'", k, v))
+  end
+else
+  for _,v in ipairs(args) do
+    checkArg(1,v,"string")
+    handlePair(splitPair(v))
+  end
+end
+
+return ec