| 1 | babeltrace-source.text.dmesg(7) |
| 2 | =============================== |
| 3 | :manpagetype: component class |
| 4 | :revdate: 5 October 2017 |
| 5 | |
| 6 | |
| 7 | NAME |
| 8 | ---- |
| 9 | babeltrace-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:babeltrace-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:babeltrace-plugin-text(7), |
| 80 | man:babeltrace-intro(7) |