Re: tail question

[Paul Eggert]

Warren L Dodge <address@hidden> writes:

> Another person told me about this to force old behavior.
> 
>   ./configure CPPFLAGS=-D_POSIX2_VERSION=199209
> 
> Should I do this with "all" configures to make sure of what I have?

Better is "./configure DEFAULT_POSIX2_VERSION=199209" as described in
coreutils/NEWS.  The CPPFLAGS method doesn't work on all platforms.

> Also do you know what version of the coreutils this appeared in?

The above "configure" behavior first appeared in 5.1.1.

The 'tail -1' behavior change has been around for a couple of years
anyway: it predates coreutils 4.5.1, the first version of coreutils
proper.  It didn't become much of an issue, though, until systems
appeared that claimed conformance to the 2001 POSIX standard.  This
started happening a few months ago.

> The linux /usr/bin/tail I am using does both formats.

Most likely it was generated on a system that claims conformance to
1992 POSIX, not 2001 POSIX.  1992 POSIX requires support for both the
old (tail -1) and the new (tail -n 1) syntax.  2001 POSIX declares the
old syntax obsolete, and requires that support for it be removed.