On 7/13/16, Jeff Law <l...@redhat.com> wrote:
> On 06/27/2016 08:10 PM, Eric Gallager wrote:
>> The last time I ran ./contrib/download_prerequisites, I already had
>> previous symlinks set up from a previous run of the script, so `ln`
>> followed the existing symlinks and created the new ones in the
>> directories to which the symlinks pointed. This patch should fix that
>> by removing the old symlinks before creating new ones. (For some
>> reason the `-f` flag to `ln` that was already there wasn't enough for
>> me.) Tested by running the script and ensuring that the new isl
>> symlink pointed to the correct directory, and that there were no bad
>> symlinks in the old isl directory. Could someone commit this trivial
>> patch for me, or something like it? I don't have write access.
> I'd really rather know why the "-f" flag didn't work for you. The whole
> point of -f is to remove the destination file first.
>
> Jeff
>
Reading my ln manpage, it describes the "-f" flag like this:
-f If the target file already exists, then unlink it so that the
link may occur. (The -f option overrides any previous -i
options.)
Okay, so that seems like it should do what you say, but the manpage
also describes a separate uppercase "-F" option:
-F If the target file already exists and is a directory, then
remove it so that the link may occur. The -F option should be
used with either -f or -i options. If none is specified, -f is
implied. The -F option is a no-op unless -s option is speci-
fied.
So it seems to imply that "-f" will only remove the destination file
if it's a regular file, while "-F" is needed if the destination file
is a directory. The page also has this to say about "-F" later:
The -F option is FreeBSD extention and should not be used in portable
scripts.
So this could be a BSD vs. GNU thing.
