Linux – Difference Between ATTRS and ATTR in udev Rules

linuxudev

What's the difference between ATTRS and ATTR in udev rules? Aren't both attributes? Why the distinction?

Best Answer

The singular form of udev criteria (KERNEL, SUBSYSTEM, DRIVER, ATTR) only match the device being added, whereas the plural forms (including ATTRS) match the device being added or any of its parent devices.

See the Writing udev rules guide for details.

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What’s the difference between udev and hald

One important difference is that HAL is deprecated.

Udev, how to prevent further rules to be run

You can use GOTO in a rule to skip to a label as soon as the rule has been applied. If the label is at the very end of the rules, then all subsequent rules are skipped.

So in 30.myusb.rules:

ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="1f75", ATTRS{idProduct}=="0902", RUN+="/bin/mount.30.1f75.0902.sh", GOTO="myusb_end"

And at the end of 31.myusb.rules:

LABEL="myusb_end"

Or use GOTO="very_end", and put LABEL="very_end" in a file that is loaded last (/etc/udev/rules.d/zzzzzzzz.rules).

Best Answer

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What’s the difference between udev and hald

Udev, how to prevent further rules to be run

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