From: "SHULTZ,BARRY (HP-Israel,ex1)" <barry_shultz@...>
Date: 2001-04-05T21:06:33+09:00
Subject: [ruby-talk:13511] Re: BUG?: HP-UX 10.20 and IO#gets followed 	 by IO#puts

>      When a file is opened with update mode (+ as the  second  or
>      third character in the mode argument), both input and output
>      may be performed on the associated stream.  However,  output
>      must   not   be   directly  followed  by  input  without  an
>      intervening call to fflush(3S)  or  to  a  file  positioning
>      function ( fseek(3S), fsetpos(3S) or rewind( 3S)), and input
>                                                         ^^^^^^^^
>      must not be directly followed by output without an interven-
>      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>      ing  call  to  a file positioning function, unless the input
>      operation encounters end-of-file.
>  

OK, at least the Unix case is clear now. Thanks again.

Barry