Re: Bug in pr?

[Paul Eggert]

Jim Meyering <address@hidden> writes:

> Richard Stallman <address@hidden> wrote:
>> The pr program has what may arguably be a bug: when used with -F, it
>> ends the last line on a page with a newline.  With the printer
>> here (and maybe all printers nowadays), that causes a blank page
>> after each real page.

I looked into this.  GNU 'pr' differs from BSD 'pr' here, and I think
the difference explains the problem.  With BSD 'pr', the -F option
affects only whether formfeeds or newlines are used to separate pages.
With GNU 'pr', -F also shrinks the header and omits the trailer of 5
blank lines.  Omitting the trailer causes GNU pr to try to print on
the very last line of the output page, which is a portability hassle:
some printers and printer emulators ignore newline before formfeed on
the last line of a page, while others don't.

The simplest fix is to change GNU pr to behave like BSD pr.  I'll
submit a patch along those lines shortly, to bug-coreutils.  This is
an incompatible change, since it will output 7 fewer lines per page
when you specify -F; but it does make sense for -F to affect only
whether formfeeds are used, not the layout of the header and the
footer.  I suspect GNU pr behaves the way that it does for
compatibility with Solaris /bin/pr, but that's less of a factor
nowadays.