Re: [Emacs-diffs] master 2534676 2/2: Simplify setfattr use by assuming GNU make
Paul Eggert <[email protected]>
| Newsgroups | gmane.comp.sysutils.autoconf.patches,gmane.emacs.devel |
|---|---|
| Organization | UCLA Computer Science Department |
| Message-ID | <[email protected]> |
On 01/02/2015 11:12 AM, Glenn Morris wrote: > The autoconf manual says "Don't rely on ln having a -f option." Although that was good advice in the early 1990s when that part of the Autoconf manual was written, the advice has been obsolete for years. I installed the attached patch into Autoconf to fix this (after bumping Autoconf's copyright year). I'm CC:ing this to autoconf-patches.
0001-doc-f-is-now-portable-for-cp-and-ln.patch
(text/x-patch, 1.9 KB)
From 4774ff5c33d34bb6ad21c06f3c2b54d6e700740e Mon Sep 17 00:00:00 2001 From: Paul Eggert <[email protected]> Date: Fri, 2 Jan 2015 13:02:48 -0800 Subject: [PATCH] doc: -f is now portable for cp and ln This follows up on a comment by Glenn Morris in: http://lists.gnu.org/archive/html/emacs-devel/2015-01/msg00011.html * doc/autoconf.texi (Limitations of Usual Tools): Remove circa-1990 advice about avoiding cp -f and ln -f. Although that advice was reasonable for the early 1990s, the -f option is portable for both cp and ln nowadays. These options were standardized in POSIX 1003.2-1992, and pre-POSIX systems such as SunOS 4 are no longer of practical concern. --- doc/autoconf.texi | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/doc/autoconf.texi b/doc/autoconf.texi index 639cec2..d9e833d 100644 --- a/doc/autoconf.texi +++ b/doc/autoconf.texi @@ -18684,9 +18684,7 @@ avoid this problem, omit the trailing slashes. For example, use @samp{cp -R source /tmp/newdir} rather than @samp{cp -R source /tmp/newdir/} if @file{/tmp/newdir} does not exist. -@c This is thanks to Ian. -The ancient SunOS 4 @command{cp} does not support @option{-f}, although -its @command{mv} does. +The @option{-f} option is portable nowadays. @cindex timestamp resolution Traditionally, file timestamps had 1-second resolution, and @samp{cp @@ -19088,9 +19086,11 @@ the workaround is to use @command{join -a1 file1 file2} instead. @item @command{ln} @c --------------- @prindex @command{ln} +The @option{-f} option is portable nowadays. + @cindex Symbolic links -Don't rely on @command{ln} having a @option{-f} option. Symbolic links -are not available on old systems; use @samp{$(LN_S)} as a portable substitute. +Symbolic links are not available on some systems; use @samp{$(LN_S)} as +a portable substitute. For versions of the DJGPP before 2.04, @command{ln} emulates symbolic links -- 2.1.0