babeltrace2-source.text.dmesg(7)
===============================
:manpagetype: component class
:revdate: 5 October 2017


NAME
----
babeltrace2-source.text.dmesg - Babeltrace's Linux kernel ring buffer
source component class


DESCRIPTION
-----------
The Babeltrace compcls:source.text.dmesg component class, provided by
the man:babeltrace2-plugin-text(7) plugin, once instantiated, reads the
lines of a Linux kernel ring buffer, as printed by the man:dmesg(1)
tool, and emits corresponding event notifications on its output port.

The events created by a compcls:source.text.dmesg component are named
`string` and contain a single payload string field named `str` which
contains the corresponding ring buffer line.

By default, a compcls:source.text.dmesg component reads the lines of the
standard input stream. You can make the component read the lines of a
text file instead with the param:path parameter.

By default, the component tries to extract the timestamps of the kernel
ring buffer lines and use them as the created events's timestamps. A
typical man:dmesg(1) line looks like this:

----
[87166.510937] PM: Finishing wakeup.
----

In the last example, the `[87166.510937]` part is the timestamp to
extract. You can make the component not extract timestamps from lines
with the param:no-extract-timestamp parameter.


INITIALIZATION PARAMETERS
-------------------------
The following parameters are optional.

param:no-extract-timestamp=`yes` (boolean)::
    Do :not: extract timestamps from the kernel ring buffer lines: set
    the created event's payload's `str` field to the whole line,
    including any timestamp prefix.

param:path='PATH' (string)::
    Read the kernel ring buffer lines from the file 'PATH' instead of
    the standard input stream.


PORTS
-----
Output
~~~~~~
`out`::
    Single output port to which the component sends the created
    notifications.


QUERY OBJECTS
-------------
This component class has no objects to query.


ENVIRONMENT VARIABLES
---------------------
include::common-common-compat-env.txt[]


include::common-footer.txt[]


SEE ALSO
--------
man:babeltrace2-plugin-text(7),
man:babeltrace2-intro(7)