====== UDEV 规则配置 ======
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- 官方文档：https://www.reactivated.net/writing_udev_rules.html
- `KERNEL / SUBSYSTEM / DRIVER / ATTR` 只匹配本设备不匹配父设备.  加个`S`， 就可以在本设备以及父设备整条链上搜索匹配。 `KERNELS / SUBSYSTEMS / DRIVERS / ATTRS`
- 字符匹配：
	```bash
	* - match any character, zero or more times
	? - match any character exactly once
	[] - match any single character specified in the brackets, ranges are also permitted
	```
- 替换符

	```bash
	$kernel, %k  		The kernel name for this device.
	$number, %n  		The kernel number for this device. For example, "sda3" has kernel number 3.
	$devpath, %p		The devpath of the device.
	$id, %b			The name of the device matched while searching the devpath upwards for SUBSYSTEMS, KERNELS, DRIVERS, and ATTRS.
	$driver			The driver name of the device matched while searching the devpath upwards for SUBSYSTEMS, KERNELS, DRIVERS, and ATTRS.
	$attr{file}, %s{file}	The value of a sysfs attribute found at the device where all keys of the rule have matched. If the matching
				device does not have such an attribute, and a previous KERNELS, SUBSYSTEMS, DRIVERS, or ATTRS test selected a
				parent device, then the attribute from that parent device is used.
				If the attribute is a symlink, the last element of the symlink target is returned as the value.
	%%：			符号 % 本身。
	$$：			符号 $ 本身。
	```
- 获取设备信息：
	- `udevadm info` 指令 取代   `udevinfo`
	- `udevadm info -a -p /sys/block/sda`  获取设备ATTRS各项属性
- `last_rule` - 到本条规则为止，后续规则不起作用
	- `OPTIONS+="last_rule"`
- `udevadm test /sys/block/sda` 测试规则
- `udevadm control --reload-rules` 修改规则后重新加载生效
  - 或者 `udevadm control -R`
-  `NAME=` 只对网路设备起作用
```bash
NAME
       The name to use for a network interface. See
       systemd.link(5) for a higher-level mechanism
       for setting the interface name. The name of a
       device node cannot be changed by udev, only
       additional symlinks can be created.
```

## 示例
- ubuntu默认的usb storage mount 规则 `/etc/udev/rules.d/10-usb-storage.rules` ：
```bash
KERNEL!="sd[a-z][0-9]",GOTO="automount_exit"
ACTION=="add", SUBSYSTEM=="block", RUN+="/bin/mkdir -p /media/%k", RUN+="/usr/bin/mount $devnode /media/%k"
ACTION=="remove", RUN+="/usr/bin/umount /media/%k",RUN+="/bin/rmdir /media/%k"
LABEL="automount_exit"
```



- 指定类型
```bash
ACTION=="add", KERNEL=="sd*[0-9]", SUBSYSTEMS=="block", SYMLINK+="sd-myself", ATTRS{model}=="Your_Harddisk_Model"`
```
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