Re: [dpdk-dev] [PATCH v1] cmdline: rework as a wrapper to libedit

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 17-Apr-18 4:21 PM, Adrien Mazarguil wrote:
> Disclaimer: this patch must not be confused with the CLI library [1]
> (work in progress) that will eventually supersede librte_cmdline itself
> with a different API.
> 
> Rather, it modifies librte_cmdline to delegate all the heavy lifting
> (terminal and history handling), strips unused features and re-implements
> what remains of its public API as a wrapper to the editline library (also
> known as libedit) [2], a well-known, BSD-licensed and widely available
> library used by many projects which does everything needed and more [3].
> 
> This approach was chosen because converting librte_cmdline as a wrapper to
> a more capable library was easier and faster than addressing its
> shortcomings and results in much less code to maintain in DPDK.
> 
> It also provides a drop-in solution for applications that rely on
> librte_cmdline. They benefit from greatly improved command line handling
> without a meaningful impact on their code base.
> 
> The main motivation behind this patch is testpmd's flow (rte_flow) command,
> which requires support for dynamic tokens and very long lines that must be
> broken down when displayed. This is not supported by librte_cmdline's
> limited terminal handling capabilities, resulting in a rather frustrating
> user experience.
> 
> It had to be addressed given the importance of testpmd as one of the
> primary tool used by PMD developers.
> 
> This rework results in the following changes:
> 
> - Removed circular buffer management interface for command history
>    (cmdline_cirbuf.c), command history being handled by libedit.
> - Removed raw command-line interpreter (cmdline_rdline.c).
> - Removed raw terminal handler (cmdline_vt100.c).
> - Removed all test/example code for the above.
> - Re-implemented high level interactive and non-interactive command-line
>    handlers (cmdline.c and cmdline_socket.c) on top of libedit using its
>    native interface, not its readline compatibility layer.
> - Made struct cmdline opaque so that applications relying on librte_cmdline
>    do not need to include any libedit headers.
> - Applications do not need to include cmdline_rdline.h anymore.
> - Terminal resizing is now automatically handled.
> - New external dependency for applications relying on librte_cmdline.
> - Major version bump due to the ABI impact of these changes.
> 
> [1] http://dpdk.org/browse/draft/dpdk-draft-cli/
> [2] http://thrysoee.dk/editline/
> [3] http://netbsd.gw.com/cgi-bin/man-cgi?editline++NetBSD-current
> 
> Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
> Cc: Olivier Matz <olivier.matz@6wind.com>
> Cc: Keith Wiles <keith.wiles@intel.com>
> Cc: Jingjing Wu <jingjing.wu@intel.com>
> Cc: Thomas Monjalon <thomas@monjalon.net>
> Cc: Ferruh Yigit <ferruh.yigit@intel.com>
> Cc: Jim Thompson <jim@netgate.com>
> 
> --
> 
> No fundamental change since the original RFC [4], except it's been rebased
> several times and Meson build support was added in the meantime. Commit log
> was also shortened a bit.
> 
> I'm re-sending this because I think it's useful, at least to me (duh). As
> the maintainer of rte_flow, I spend most of my time typing flow commands in
> testpmd and libedit makes that a pleasant experience.
> 
> Try it out! And don't hesitate to send your acked-by line to get this in
> time for 18.05 :)
> 
> [4] http://dpdk.org/ml/archives/dev/2017-November/081605.html
> ---

<...>

> +	uint32_t error:1;
> +	char prompt[RDLINE_PROMPT_SIZE];
> +};
> +
> +void
> +cmdline_set_prompt(struct cmdline *cl, const char *prompt)
>   {
> -	struct cmdline *cl = rdl->opaque;
> -	int ret;
> -	ret = cmdline_parse(cl, buf);
> -	if (ret == CMDLINE_PARSE_AMBIGUOUS)
> -		cmdline_printf(cl, "Ambiguous command\n");
> -	else if (ret == CMDLINE_PARSE_NOMATCH)
> -		cmdline_printf(cl, "Command not found\n");
> -	else if (ret == CMDLINE_PARSE_BAD_ARGS)
> -		cmdline_printf(cl, "Bad arguments\n");
> +	if (!cl || !prompt)
> +		return;
> +	snprintf(cl->prompt, sizeof(cl->prompt), "%s", prompt);

Didn't look through the entire patch yet, but this stood out - please 
use strlcpy() :)

-- 
Thanks,
Anatoly