doc/man/babeltrace2-source.text.dmesg.7.txt

   1 babeltrace2-source.text.dmesg(7)
   2 ===============================
   3 :manpagetype: component class
   4 :revdate: 5 October 2017
   5
   6
   7 NAME
   8 ----
   9 babeltrace2-source.text.dmesg - Babeltrace's Linux kernel ring buffer
  10 source component class
  11
  12
  13 DESCRIPTION
  14 -----------
  15 The Babeltrace compcls:source.text.dmesg component class, provided by
  16 the man:babeltrace2-plugin-text(7) plugin, once instantiated, reads the
  17 lines of a Linux kernel ring buffer, as printed by the man:dmesg(1)
  18 tool, and emits corresponding event notifications on its output port.
  19
  20 The events created by a compcls:source.text.dmesg component are named
  21 `string` and contain a single payload string field named `str` which
  22 contains the corresponding ring buffer line.
  23
  24 By default, a compcls:source.text.dmesg component reads the lines of the
  25 standard input stream. You can make the component read the lines of a
  26 text file instead with the param:path parameter.
  27
  28 By default, the component tries to extract the timestamps of the kernel
  29 ring buffer lines and use them as the created events's timestamps. A
  30 typical man:dmesg(1) line looks like this:
  31
  32 ----
  33 [87166.510937] PM: Finishing wakeup.
  34 ----
  35
  36 In the last example, the `[87166.510937]` part is the timestamp to
  37 extract. You can make the component not extract timestamps from lines
  38 with the param:no-extract-timestamp parameter.
  39
  40
  41 INITIALIZATION PARAMETERS
  42 -------------------------
  43 The following parameters are optional.
  44
  45 param:no-extract-timestamp=`yes` (boolean)::
  46     Do :not: extract timestamps from the kernel ring buffer lines: set
  47     the created event's payload's `str` field to the whole line,
  48     including any timestamp prefix.
  49
  50 param:path='PATH' (string)::
  51     Read the kernel ring buffer lines from the file 'PATH' instead of
  52     the standard input stream.
  53
  54
  55 PORTS
  56 -----
  57 Output
  58 ~~~~~~
  59 `out`::
  60     Single output port to which the component sends the created
  61     notifications.
  62
  63
  64 QUERY OBJECTS
  65 -------------
  66 This component class has no objects to query.
  67
  68
  69 ENVIRONMENT VARIABLES
  70 ---------------------
  71 include::common-common-compat-env.txt[]
  72
  73
  74 include::common-footer.txt[]
  75
  76
  77 SEE ALSO
  78 --------
  79 man:babeltrace2-plugin-text(7),
  80 man:babeltrace2-intro(7)