| .. | .. |
|---|
| 6 | 6 | Enable passing additional variables for synthetic uevents that |
|---|
| 7 | 7 | are generated by writing /sys/.../uevent file. |
|---|
| 8 | 8 | |
|---|
| 9 | | - Recognized extended format is ACTION [UUID [KEY=VALUE ...]. |
|---|
| 9 | + Recognized extended format is:: |
|---|
| 10 | 10 | |
|---|
| 11 | | - The ACTION is compulsory - it is the name of the uevent action |
|---|
| 12 | | - ("add", "change", "remove"). There is no change compared to |
|---|
| 13 | | - previous functionality here. The rest of the extended format |
|---|
| 14 | | - is optional. |
|---|
| 11 | + ACTION [UUID [KEY=VALUE ...] |
|---|
| 12 | + |
|---|
| 13 | + The ACTION is compulsory - it is the name of the uevent |
|---|
| 14 | + action (``add``, ``change``, ``remove``). There is no change |
|---|
| 15 | + compared to previous functionality here. The rest of the |
|---|
| 16 | + extended format is optional. |
|---|
| 15 | 17 | |
|---|
| 16 | 18 | You need to pass UUID first before any KEY=VALUE pairs. |
|---|
| 17 | | - The UUID must be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" |
|---|
| 19 | + The UUID must be in ``xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`` |
|---|
| 18 | 20 | format where 'x' is a hex digit. The UUID is considered to be |
|---|
| 19 | 21 | a transaction identifier so it's possible to use the same UUID |
|---|
| 20 | 22 | value for one or more synthetic uevents in which case we |
|---|
| 21 | 23 | logically group these uevents together for any userspace |
|---|
| 22 | 24 | listeners. The UUID value appears in uevent as |
|---|
| 23 | | - "SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment |
|---|
| 25 | + ``SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`` environment |
|---|
| 24 | 26 | variable. |
|---|
| 25 | 27 | |
|---|
| 26 | 28 | If UUID is not passed in, the generated synthetic uevent gains |
|---|
| 27 | | - "SYNTH_UUID=0" environment variable automatically. |
|---|
| 29 | + ``SYNTH_UUID=0`` environment variable automatically. |
|---|
| 28 | 30 | |
|---|
| 29 | 31 | The KEY=VALUE pairs can contain alphanumeric characters only. |
|---|
| 32 | + |
|---|
| 30 | 33 | It's possible to define zero or more pairs - each pair is then |
|---|
| 31 | 34 | delimited by a space character ' '. Each pair appears in |
|---|
| 32 | | - synthetic uevent as "SYNTH_ARG_KEY=VALUE". That means the KEY |
|---|
| 33 | | - name gains "SYNTH_ARG_" prefix to avoid possible collisions |
|---|
| 35 | + synthetic uevent as ``SYNTH_ARG_KEY=VALUE``. That means the KEY |
|---|
| 36 | + name gains ``SYNTH_ARG_`` prefix to avoid possible collisions |
|---|
| 34 | 37 | with existing variables. |
|---|
| 35 | 38 | |
|---|
| 36 | | - Example of valid sequence written to the uevent file: |
|---|
| 39 | + Example of valid sequence written to the uevent file:: |
|---|
| 37 | 40 | |
|---|
| 38 | 41 | add fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed A=1 B=abc |
|---|
| 39 | 42 | |
|---|
| 40 | | - This generates synthetic uevent including these variables: |
|---|
| 43 | + This generates synthetic uevent including these variables:: |
|---|
| 41 | 44 | |
|---|
| 42 | 45 | ACTION=add |
|---|
| 43 | 46 | SYNTH_ARG_A=1 |
|---|
| 44 | 47 | SYNTH_ARG_B=abc |
|---|
| 45 | 48 | SYNTH_UUID=fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed |
|---|
| 49 | + |
|---|
| 46 | 50 | Users: |
|---|
| 47 | 51 | udev, userspace tools generating synthetic uevents |
|---|