Subject: Re: sort(1) behavior?
To: NetBSD-current Discussion List <current-users@NetBSD.org>
From: Steven M. Bellovin <firstname.lastname@example.org>
Date: 04/10/2004 10:21:14
In message <m1BC8y6-0002VGC@proven.weird.com>, "Greg A. Woods" writes:
>[ On Thursday, April 8, 2004 at 16:54:43 (-0500), MLH wrote: ]
>> Subject: sort(1) behavior?
>> There is seen a high degree of variability in results with sort(1)
>> on various systems, particularly when using the -k field specifications.
>I'll note first off that you're using '-n' and you've got what appear to
>be decimal fractions in your test data. I haven't looked into all the
>issues surrounding the interpretation of decimal numbers with decimal
>fractions by sort, but I have found that it doesn't always do what one
>might expect despite claims in the NetBSD manual page.
>Note also that it appears as if POSIX doesn't require support of decimal
>numbers (quoted from SuSv3, aka IEEE Std 1003.1-2001):
> Restrict the sort key to an initial numeric string, consisting
> of optional <blank>s, optional minus sign, and zero or more
> digits with an optional radix character and thousands separators
> (as defined in the current locale), which shall be sorted by
> arithmetic value. An empty digit string shall be treated as
> zero. Leading zeros and signs on zeros shall not affect
I don't read it that way -- I read that as saying that the radix point
need not appear in the actual number being sorted, not that the sort
command can ignore it if it occurs. (OTOH, in the past I've noticed
significant non-portability of sort command option strings between
different operating systems.)
--Steve Bellovin, http://www.research.att.com/~smb