Re: Help a sed noob

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 3, 2007, 23:38 UTC
Message-ID: <7vhcngkx38.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <fcaeb9bf0708031622w25ab6e9ev61372169cfc0bd98@mail.gmail.com>

"Nguyen Thai Ngoc Duy" <pclouds@gmail.com> writes:

Show 12 quoted lines

> There is a construct like this in git-parse-remote.sh which makes
> busybox ash unhappy:
>
>                 sed -ne '/^URL: */{
>                         s///p
>                         q
>                 }' "$GIT_DIR/remotes/$1"
>
> It complains about "no previous regexp" while gnu sed is ok. Can
> anyone explain to me what does "s///p" do? GNU Sed info page says
> nothing about empty regexp. If I replace it with "s/\(.*\)/\1/p" then
> I get "URL: " along with the remote path.

Traditionally empty LHS regexp means "the same as last match". Replace it with "s/^URL: *//p" and you would be Ok.