X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=udev%2Fudev.xml;h=ab82012cee8a92d2c12fa04db0397f86132f621b;hb=1021e6dfcc339728d83bfa5a3e8cd73bb37dbcef;hp=b9884e521ce42fea5f2277c4f96ef564ac344ceb;hpb=b6a49cd681ac3ffd0702a79741fb482db85b5a36;p=elogind.git diff --git a/udev/udev.xml b/udev/udev.xml index b9884e521..ab82012ce 100644 --- a/udev/udev.xml +++ b/udev/udev.xml @@ -71,14 +71,18 @@ Rules files The udev rules are read from the files located in the - default rules directory /lib/udev/rules.d/, - the custom rules directory /etc/udev/rules.d/ - and the temporary rules directory /run/udev/rules.d/. - All rule files are collectively sorted and processed in lexical order, - regardless of the directories in which they live. However, files in - /etc/udev/rules.d/ take precedence over files with - the same name in /lib/udev/rules.d/; this can be - used to ignore a default rules file if needed. + system rules directory /lib/udev/rules.d/, + the local administration directory /etc/udev/rules.d/ + and the volatile runtime directory /run/udev/rules.d/. + All rules files are collectively sorted and processed in lexical order, + regardless of the directories in which they live. However, files with + identical file names replace each other. Files in /run + have the highest priority, files in /etc take precedence + over files with the same name in /lib. This can be + used to overwrite a system rules file if needed; a symlink in + /etc with the same name as a rules file in + /lib, pointing to /dev/null, + disables the rules file entirely. Rule files must have the extension .rules; other extensions are ignored. @@ -233,6 +237,13 @@ + + + + Search the devpath upwards for a device with matching tag. + + + @@ -441,7 +452,7 @@ - Import a single property from the kernel commandline. For simple flags + Import a single property from the kernel command line. For simple flags the value of the property is set to '1'. @@ -456,18 +467,15 @@ - If no option is given, udev chooses between - and based on the executable bit of the file - permissions. - Wait for a file to become available or until a 10 - seconds timeout expires. The path is relative to the sysfs device, - i. e. if no path is specified this waits for an attribute to appear. + Wait for a file to become available or until a timeout of + 10 seconds expires. The path is relative to the sysfs device; + if no path is specified, this waits for an attribute to appear. @@ -501,7 +509,7 @@ - Apply the permissions specified in this rule to a static device node with + Apply the permissions specified in this rule to the static device node with the specified name. Static device nodes might be provided by kernel modules or copied from /lib/udev/devices. These nodes might not have a corresponding kernel device at the time udevd is started; they can trigger @@ -511,8 +519,8 @@ - Watch the device node with inotify; when closed after being opened for - writing, a change uevent is synthesised. + Watch the device node with inotify; when the node is closed after being opened for + writing, a change uevent is synthesized. @@ -528,10 +536,10 @@ The , , , , , and - fields support simple printf-like string substitutions. The - format chars gets applied after all rules have been processed, right before the program - is executed. It allows the use of device properties set by earlier matching - rules. For all other fields, substitutions are applied while the individual rule is + fields support simple string substitutions. The + substitutions are performed after all rules have been processed, right before the program + is executed, allowing for the use of device properties set by earlier matching + rules. For all other fields, substitutions are performed while the individual rule is being processed. The available substitutions are: @@ -580,9 +588,9 @@ 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, use the attribute from that - parent device. - If the attribute is a symlink, the last element of the symlink target is + 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. @@ -612,9 +620,9 @@ , The string returned by the external program requested with PROGRAM. - A single part of the string, separated by a space character may be selected + A single part of the string, separated by a space character, may be selected by specifying the part number as an attribute: . - If the number is followed by the '+' char this part plus all remaining parts + If the number is followed by the '+' character, this part plus all remaining parts of the result string are substituted: @@ -637,8 +645,8 @@ - The current list of symlinks, separated by a space character. The value is - only set if an earlier rule assigned a value, or during a remove events. + A space-separated list of the current symlinks. The value is + only set during a remove event or if an earlier rule assigned a value. @@ -659,7 +667,7 @@ , - The name of a created temporary device node to provide access to + The name of a temporary device node created to provide access to the device from a external program before the real node is created.