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c1f82f3b | 1 | babeltrace2-source.text.dmesg(7) |
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2 | =============================== |
3 | :manpagetype: component class | |
4 | :revdate: 5 October 2017 | |
5 | ||
6 | ||
7 | NAME | |
8 | ---- | |
c1f82f3b | 9 | babeltrace2-source.text.dmesg - Babeltrace's Linux kernel ring buffer |
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10 | source component class |
11 | ||
12 | ||
13 | DESCRIPTION | |
14 | ----------- | |
15 | The Babeltrace compcls:source.text.dmesg component class, provided by | |
c1f82f3b | 16 | the man:babeltrace2-plugin-text(7) plugin, once instantiated, reads the |
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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 | -------- | |
c1f82f3b MJ |
79 | man:babeltrace2-plugin-text(7), |
80 | man:babeltrace2-intro(7) |