[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: diff -b does not actually work with newlines
From: |
David Kastrup |
Subject: |
Re: diff -b does not actually work with newlines |
Date: |
Fri, 13 Jul 2007 21:04:22 +0200 |
User-agent: |
Gnus/5.11 (Gnus v5.11) Emacs/23.0.51 (gnu/linux) |
Paul Eggert <address@hidden> writes:
> David Kastrup <address@hidden> writes:
>
>> The `-b' and `--ignore-space-change' options ignore white space at line
>> end,
>
> It ignores all white space at the line end, but it does not ignore the
> line end itself. This is longstanding behavior, specified by POSIX
> <http://www.opengroup.org/onlinepubs/009695399/utilities/diff.html>.
> Perhaps it could be documented more clearly (wording suggestions would
> be gratefully suggested).
Your Posix reference specifies:
-b Cause any amount of white space at the end of a line to be treated
as a single <newline> (that is, the white-space characters
preceding the <newline> are ignored) and other strings of
white-space characters, not including <newline>s, to compare
equal.
It is not a matter of "documented less clearly" if you omit "not
including <newline>s" from the option description. It is plainly
wrong.
So fine, this is long-standing behavior _and_ prescribed by Posix. It
is just described completely and utterly wrong in info file and
--help. I would then wish for the following:
a) the bit about "not including <newline>s" be added to the info
file and help string. It is absolutely essential.
b) add options, say
--one-newline-is-whitespace (for determining differing hunks, a single
newline after end-of-line space removal
counts as whitespace)
--newlines-are-whitespace (the same for multiple newlines).
This is _really_ important functionality.
Thanks,
--
David Kastrup