[2289] in Athena Bugs
tail usage message
daemon@ATHENA.MIT.EDU (David Krikorian)
Fri May 26 02:31:48 1989
Date: Fri, 26 May 89 02:31:32 EDT
From: David Krikorian <dkk@ATHENA.MIT.EDU>
To: bugs@ATHENA.MIT.EDU
Reply-To: dkk@ATHENA.MIT.EDU
The tail program gives this usage message:
dkk) tail -safdg
usage: tail [_[n][lbc][rf]] [file]
dkk) tail -safdg |& od -c
0000000 u s a g e : t a i l [ + \b _
0000020 [ n ] [ l b c ] [ r f ] ] [ f
0000040 i l e ] \n
0000045
dkk)
Note the underscore after the first left bracket in the usage message.
The string that follows is a '+' followed by a backspace, then an
underscore. This combination was intended to produce a plus sign
directly over a minus sign. As you can see above, it doesn't. I get
the correct string printed when I type either of the following two
commands:
man tail
more /paris/source/4.3/ucb/tail.c
Tail is using fprintf to output the string. I guess "more" isn't.
Typing set_edit_char at the shell (logged in as testuser on a 6.0R
machine) shows:
C-H: delete_backward
I presume that's where fprintf is getting it's ^H interpreted as a
delete, while "more" is getting around it.
Perhaps the fprintf should use "\b" rather than '^H' for backspace?
