Re: info diff - diff exitcodes (and perhaps wrong exitcodes in diff)

[Paul Eggert]

Christian Boltz <address@hidden> writes:

> improvement suggestion for 'info diff':
> ===
> Exit status
> - 0 means no differences were found
> - 1 means some differences were found and (if not using -q) a patch
>   could be created
> - 2 means trouble. Reasons for this can be:
>   - differences in binary files and -q was *not* given
>   - one of the given files does not exist or is not readable

Thanks for the suggestion.  I'd like to use the following text
instead, as I think it's a bit clearer.

   An exit status of 0 means no differences were found, 1 means some
   differences were found, and 2 means trouble.  Normally, differing
   binary files count as trouble, but this can be altered by using the
   @option{--a} or @option{--text} option, or the @option{-q} or
   @option{--brief} option.

> perhaps there's a wrong exitcode in diff. When calling
>     diff -r dir1/ dir2/   # *without* -N
> I get a message
>     Only in dir1/: file1
> with $? = 1, but the resulting patch is not complete (file1 is missing 
> in it). Shouldn't the exitcode also be 2 in this case?

I think not, as POSIX specifies that output report format in
<http://www.opengroup.org/onlinepubs/007904975/utilities/diff.html>
so it's not trouble when it occurs.