nvme-id-ctrl(1)
===============

NAME
----
nvme-id-ctrl - Send NVMe Identify Controller, return result and structure

SYNOPSIS
--------
[verse]
'nvme id-ctrl' <device> [--vendor-specific | -V] [--raw-binary | -b]
			[--output-format=<fmt> | -o <fmt>] [--verbose | -v]

DESCRIPTION
-----------
For the NVMe device given, sends an identify controller command and
provides the result and returned structure.

The <device> parameter is mandatory and may be either the NVMe character
device (ex: /dev/nvme0), or a namespace block device (ex: /dev/nvme0n1).

On success, the structure may be returned in one of several ways depending
on the option flags; the structure may be parsed by the program or the
raw buffer may be printed to stdout.

OPTIONS
-------
-b::
--raw-binary::
	Print the raw buffer to stdout. Structure is not parsed by
	program. This overrides the vendor specific and human readable options.

-V::
--vendor-specific::
	In addition to parsing known fields, this option will dump
	the vendor specific region of the structure in hex with ascii
	interpretation.

-H::
--human-readable::
	This option will parse and format many of the bit fields
	into human-readable formats.

-o <fmt>::
--output-format=<fmt>::
	Set the reporting format to 'normal', 'json' or 'binary'. Only one
	output format can be used at a time.

-v::
--verbose::
	Increase the information detail in the output.

EXAMPLES
--------
* Has the program interpret the returned buffer and display the known
fields in a human readable format:
+
------------
# nvme id-ctrl /dev/nvme0
------------
+

* In addition to showing the known fields, has the program to display
the vendor unique field:
+
------------
# nvme id-ctrl /dev/nvme0 --vendor-specific
# nvme id-ctrl /dev/nvme0 -V
------------
+
The above will dump the 'vs' buffer in hex since it doesn't know how to
interpret it.

* Have the program return the raw structure in binary:
+
------------
# nvme id-ctrl /dev/nvme0 --raw-binary > id_ctrl.raw
# nvme id-ctrl /dev/nvme0 -b > id_ctrl.raw
------------
+
It is probably a bad idea to not redirect stdout when using this mode.

* Alternatively you may want to send the data to another program that
can parse the raw buffer.
+
------------
# nvme id-ctrl /dev/nvme0 --raw-binary | nvme_parse_id_ctrl
------------
+
The parse program in the above example can be a program that shows the
structure in a way you like. The following program is such an example
that will parse it and can accept the output through a pipe, `'|'`,
as shown in the above example, or you can `'cat'` a saved output buffer to it.
------------
/* File: nvme_parse_id_ctrl.c */

#include <linux/nvme.h>
#include <stdio.h>
#include <unistd.h>

int main(int argc, char **argv)
{
	unsigned char buf[sizeof(struct nvme_id_ctrl)];
	struct nvme_id_ctrl *ctrl = (struct nvme_id_ctrl *)buf;

	if (read(STDIN_FILENO, buf, sizeof(buf)))
		return 1;

	printf("vid   : %#x\n", ctrl->vid);
	printf("ssvid : %#x\n", ctrl->ssvid);
	return 0;
}
------------

NVME
----
Part of the nvme-user suite