Re: What's cooking in git.git (Jan 2021, #02; Fri, 8)

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 9, 2021, 23:08 UTC
Message-ID: <xmqqft39emiu.fsf@gitster.c.googlers.com>
In-Reply-To: <CAJDDKr6V+kKMs4yz+YQx1AhiY5qQwENfs_yZqxXWBqmLUk2oAw@mail.gmail.com>

David Aguilar <davvid@gmail.com> writes:

Show 10 quoted lines

> Fun times in sed portability land.  After a bit of experimentation,
> this is what I've managed to whip up:
>
> cr=$(printf '\x0d')
> sed -e "/^<<<<<<< /,/^=======$cr\{0,1\}$/d" -e '/^>>>>>>> /d' tiger
>
> - Instead of \r use printf to capture CR into a string so that we can
> embed the literal using $cr.
> - DQ "..." instead of SQ '...' to allow $cr to be substituted in the string.
> - Instead of \? use \{0,1\} which seems to work on both macOS and Linux.

Ah, all the fun with avoiding GNU-ism in scripts; thanks for figuring it out.

I am perfectly fine with the above, but I also am OK with Perl script. We may even be able to generate three output files in a single pass by passing their filenames and open them for writing in the script.

> That seems to work and the tests now pass.
> If not sed, is there perhaps a perl equivalent for these multi-line
> delete-from-X-until-Y expressions that might provide better
> portability?

> I'll start putting together a patch shortly as this seems to work in
> practice.  Let me know if y'all have any sugs or if there are any
> portability pitfalls I'm not considering.