From: Jonathan Nieder <jrnieder@gmail.com>
To: "brian m. carlson" <sandals@crustytoothpaste.net>
Cc: git@vger.kernel.org, Jeff King <peff@peff.net>,
Duy Nguyen <pclouds@gmail.com>
Subject: Re: [PATCH] diff: add support for reading files literally with --no-index
Date: Thu, 3 Jan 2019 18:18:55 -0800 [thread overview]
Message-ID: <20190104021855.GB97188@google.com> (raw)
In-Reply-To: <20181220002610.43832-1-sandals@crustytoothpaste.net>
Hi,
brian m. carlson wrote:
> In some shells, such as bash and zsh, it's possible to use a command
> substitution to provide the output of a command as a file argument to
> another process, like so:
>
> diff -u <(printf "a\nb\n") <(printf "a\nc\n")
>
> However, this syntax does not produce useful results with git diff
> --no-index.
Thanks much for fixing this. It's something I've run into, too.
[...]
> --- a/Documentation/git-diff.txt
> +++ b/Documentation/git-diff.txt
> @@ -111,6 +111,11 @@ include::diff-options.txt[]
> "Unmerged". Can be used only when comparing the working tree
> with the index.
>
> +--literally::
> + Read the specified files literally, as `diff` would,
> + dereferencing any symlinks and reading data from pipes.
> + This option only works with `--no-index`.
I may be a minority in this opinion, but I had trouble understanding
what --literally would do from its name. I suspect we can come up
with a better name.
Unfortunately, I'm terrible at coming up with names. :-P
--dereference would be a good name when it comes to symlinks, but
it's not a good name for reading what is on the other side of a pipe.
On the plus side, it matches "diff" and "cp"'s name for the "follow
symbolic links" option.
--plain captures the desire a little better --- we want a plain
read(2) from the file instead of trying to be smart and look at
whether it is e.g. a block device. But in the context of "diff", that
would seem more like an option that affects the output.
What would you think of
- always reading from fifos instead of describing them, since I've
never encountered a use case where people want the latter
- --dereference to control whether to follow symlinks
?
[...]
> --- a/diff-no-index.c
> +++ b/diff-no-index.c
> @@ -75,7 +75,25 @@ static int populate_from_stdin(struct diff_filespec *s)
> return 0;
> }
>
> -static struct diff_filespec *noindex_filespec(const char *name, int mode)
> +static int populate_literally(struct diff_filespec *s)
> +{
> + struct strbuf buf = STRBUF_INIT;
> + size_t size = 0;
> + int fd = xopen(s->path, O_RDONLY);
> +
> + if (strbuf_read(&buf, fd, 0) < 0)
> + return error_errno("error while reading from '%s'", s->path);
> +
> + s->should_munmap = 0;
> + s->data = strbuf_detach(&buf, &size);
> + s->size = size;
> + s->should_free = 1;
> + s->read_literally = 1;
Oh! --read-literally works perfectly for me as a name. :)
Jonathan
next prev parent reply other threads:[~2019-01-04 2:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-20 0:26 [PATCH] diff: add support for reading files literally with --no-index brian m. carlson
2018-12-20 15:48 ` Jeff King
2018-12-21 0:25 ` brian m. carlson
2018-12-20 17:06 ` Duy Nguyen
2018-12-20 17:17 ` Jeff King
2018-12-20 17:23 ` Duy Nguyen
2018-12-20 17:32 ` Jeff King
2018-12-20 17:37 ` Duy Nguyen
2018-12-20 21:43 ` Ævar Arnfjörð Bjarmason
2018-12-20 23:54 ` brian m. carlson
2018-12-21 11:52 ` Johannes Schindelin
2018-12-21 23:20 ` brian m. carlson
2019-01-02 18:56 ` Junio C Hamano
2019-01-04 2:08 ` brian m. carlson
2019-01-04 2:18 ` Jonathan Nieder [this message]
2019-01-04 2:57 ` brian m. carlson
2019-01-04 19:26 ` Junio C Hamano
2019-01-05 17:39 ` brian m. carlson
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