bin/152154: /bin/csh & /bin/tcsh improperly diddle termios flags

[Robert Bonomi]

The following reply was made to PR bin/152154; it has been noted by GNATS.

From: Robert Bonomi <bonomi at mail.r-bonomi.com>
To: brde at optusnet.com.au
Cc: freebsd-bugs at freebsd.org, FreeBSD-gnats-submit at freebsd.org,
        rfg at tristatelogic.com
Subject: Re: bin/152154: /bin/csh & /bin/tcsh improperly diddle termios flags
Date: Sat, 13 Nov 2010 09:36:39 -0600 (CST)

 > From owner-freebsd-bugs at freebsd.org  Fri Nov 12 03:46:22 2010
 > Date: Fri, 12 Nov 2010 20:48:08 +1100 (EST)
 > From: Bruce Evans <brde at optusnet.com.au>
 > Subject: Re: bin/152154: /bin/csh & /bin/tcsh improperly diddle termios flags
 >
 > On Fri, 12 Nov 2010, Bruce Evans wrote:
 >
 >
 > I just remembered a related problem.  I often mistype command lines,
 > or do complicated editing of them involving many backspaces and other
 > control characters to move around or search history.  script makes a
 > mess of this by showing all the control characters, even without -k.
 
 This is  _documented behavior_.   It is, also, essentially inescapable.
 
   " BUGS
       Script places everything in the log file, including linefeeds and
       backspaces.  This is not what the naive user expects. "
 
 
 It is also documented in the body of the description:
 
   " The script utility works best with commands that do not manipulate 
     the screen.  The results are meant to emulate a hardcopy terminal, 
     not an addressable one. "
 
 Aside: some of us _count_  on script behaving that way -- capturing _every_ 
 character sent out.  
 
 Script has -no- way of knowing what is echoed 'editing' characters, and 
 what is 'significant' output.
 
 *ALL* script 'guarantees' -- in the situation involving an 'addressable'
 terminal -- is that if you play back the logfile to the _same_ type of 
 terminal is that 'what you see' on the screen on replay is "what you got'
 originally.   True "WYSIWYG".  <grin>
 
 
 > The only way to handle this right might be to have the line editor in
 > script itself ...
 
 That works _UNTIL_ you need to pass a 'line edit' character to an application.
 Heaven forbid you forget you have script running, and invoke a full-screen 
 editor (or any-other full-scrren utility for that matter) that uses one of
 the line-edit characters as it's "exit" sequence.
 
 And, even doing _that_ does not help with the 'mess' created by rummaging
 through, say, the csh cmommand history.
 
 A script functionality integrated into whichever CLI (shell) one uses
 could eliminate the line-edit / history, etc. "mess" from the logfile,
 but that is 'no help' in dealing with _all_ the other programs that 
 produce output "assuming" an 'addressable' display.  How do you log a
 'vi' session, for example?  <evil grin>
 
 For a 'cleaner' typescript, set the TERM environment variable to 'dumb'.