From a9b904a282b5ca61c9a1f41389832747689ed9cf Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Tue, 20 Apr 2010 16:26:27 -0600 Subject: [PATCH] docs: document transformation of obsolete sort syntax * doc/coreutils.texi (sort invocation): Mention the conversion. --- doc/coreutils.texi | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 7561f2a..f40993e 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -4126,6 +4126,11 @@ is counted from the first nonblank character of the field. @vindex POSIXLY_CORRECT On older systems, @command{sort} supports an obsolete origin-zero syntax @samp{+@var{pos1} [-@var{pos2}]} for specifying sort keys. +The obsolete sequence @samp{sort +@var{a}.@var{x} -@var{b}.@var{y}} +is equivalent to @samp{sort -k @var{a+1}.@var{x+1},@var{b}} if @var{y} +is @samp{0} or absent, otherwise it is equivalent to @samp{sort -k +@var{a+1}.@var{x+1},@var{b+1}.@var{y}}. + This obsolete behavior can be enabled or disabled with the @env{_POSIX2_VERSION} environment variable (@pxref{Standards conformance}); it can also be enabled when @env{POSIXLY_CORRECT} is -- 2.7.4