+ trap [ -p ] [ action ] [ sig ] ...
	      The  -p  option causes the trap action associated with each trap
	      as specified by the arguments to	be  printed  with  appropriate
	      quoting.	 Otherwise,  action will be processed as if it were an
	      argument to eval when the shell receives	signal(s)  sig.   Each
	      sig can be given as a number or as the name of the signal.  Trap
	      commands are executed in order of signal number.	Any attempt to
	      set  a trap on a signal that was ignored on entry to the current
	      shell is ineffective.  If action is omitted and the first sig is
	      a  number,  or if action is -, then the trap(s) for each sig are
	      reset to their original values.  If action is  the  null	string
	      then  this signal is ignored by the shell and by the commands it
	      invokes.	If sig is ERR then action will be executed whenever  a
	      command has a non-zero exit status.  If sig is DEBUG then action
	      will be executed before each command.  The variable  .sh.command
	      will  contain  the  contents  of	the  current command line when
	      action is running.  If the exit status of the trap is 2 the com-
	      mand  will  not  be executed.  If the exit status of the trap is
	      255 and inside a function or a dot script, the function  or  dot
	      script  will return.  If sig is 0 or EXIT and the trap statement
	      is executed inside the body of a function defined with the func-
	      tion  name syntax, then the command action is executed after the
	      function completes.  If sig is 0 or EXIT for a trap set  outside
	      any  function  then  the command action is executed on exit from
	      the shell.  If sig is KEYBD, then action will be executed  when-
	      ever  a key is read while in emacs, gmacs, or vi mode.  The trap
	      command with no arguments prints a list of  commands  associated
	      with each signal number.