diff options
| -rw-r--r-- | extras/volume_id/vol_id.8 | 22 | ||||
| -rw-r--r-- | udev.7 | 224 | ||||
| -rw-r--r-- | udev.xml | 36 | ||||
| -rw-r--r-- | udevd.8 | 34 | ||||
| -rw-r--r-- | udevinfo.8 | 30 | ||||
| -rw-r--r-- | udevmonitor.8 | 6 | ||||
| -rw-r--r-- | udevsettle.8 | 10 | ||||
| -rw-r--r-- | udevstart.8 | 2 | ||||
| -rw-r--r-- | udevtest.8 | 2 | ||||
| -rw-r--r-- | udevtrigger.8 | 34 |
10 files changed, 302 insertions, 98 deletions
diff --git a/extras/volume_id/vol_id.8 b/extras/volume_id/vol_id.8 index 3129ab1b91..d57ecc6bf7 100644 --- a/extras/volume_id/vol_id.8 +++ b/extras/volume_id/vol_id.8 @@ -1,6 +1,6 @@ .\" Title: vol_id .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: March 2006 .\" Manual: vol_id .\" Source: volume_id @@ -22,22 +22,32 @@ is usually called from a udev rule, to provide udev with the filesystem type, th \fBvol_id\fR supports all common filesystem formats and detects various raid setups to prevent the recognition of raid members as a volume with a filesystem. .SH "OPTIONS" -.TP 3n +.PP \fB\-\-export\fR +.RS 3n print all values in key/value format to import them into the environment. -.TP 3n +.RE +.PP \fB\-t\fR +.RS 3n print the filesystem type -.TP 3n +.RE +.PP \fB\-l\fR +.RS 3n print the label of a volume -.TP 3n +.RE +.PP \fB\-u\fR +.RS 3n print the uuid of a volume +.RE .SH "ENVIRONMENT" -.TP 3n +.PP \fBUDEV_LOG\fR +.RS 3n Set the syslog priority. +.RE .SH "EXIT STATUS" .PP \fBvol_id\fR @@ -1,6 +1,6 @@ .\" Title: udev .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: August 2005 .\" Manual: udev .\" Source: udev @@ -31,23 +31,28 @@ All udev configuration files are placed in .PP udev expects its main configuration file at \fI/etc/udev/udev.conf\fR. It consists of a set of variables allowing the user to override default udev values. The following variables can be set: -.TP 3n +.PP \fBudev_root\fR +.RS 3n Specifies where to place the device nodes in the filesystem. The default value is \fI/dev\fR. -.TP 3n +.RE +.PP \fBudev_rules\fR +.RS 3n The name of the udev rules file or directory to look for files with the suffix \fI.rules\fR. Multiple rule files are read in lexical order. The default value is \fI/etc/udev/rules.d\fR. -.TP 3n +.RE +.PP \fBudev_log\fR +.RS 3n The logging priority. Valid values are the numerical syslog priorities or their textual representations: \fBerr\fR, \fBinfo\fR and \fBdebug\fR. -.\" end of SS subsection "Configuration file" +.RE .SS "Rules files" .PP The udev rules are read from the files located in the @@ -55,114 +60,197 @@ The udev rules are read from the files located in the directory or at the location specified value in the configuration file. Every line in the rules file contains at least one key value pair. There are two kind of keys, match and assignment keys. If all match keys are matching against its value, the rule gets applied and the assign keys get the specified value assigned. A matching rule may specify the name of the device node, add a symlink pointing to the node, or run a specified program as part of the event handling. If no matching rule is found, the default device node name is used. .PP A rule may consists of a list of one or more key value pairs separated by a comma. Each key has a distinct operation, depending on the used operator. Valid operators are: -.TP 3n +.PP \fB==\fR +.RS 3n Compare for equality. -.TP 3n +.RE +.PP \fB!=\fR +.RS 3n Compare for non\-equality. -.TP 3n +.RE +.PP \fB=\fR +.RS 3n Assign a value to a key. Keys that represent a list, are reset and only this single value is assigned. -.TP 3n +.RE +.PP \fB+=\fR +.RS 3n Add the value to a key that holds a list of entries. -.TP 3n +.RE +.PP \fB:=\fR +.RS 3n Assign a value to a key finally; disallow any later changes, which may be used to prevent changes by any later rules. +.RE .PP The following key names can be used to match against device properties: -.TP 3n +.PP \fBACTION\fR +.RS 3n Match the name of the event action. -.TP 3n +.RE +.PP \fBDEVPATH\fR +.RS 3n Match the devpath of the event device. -.TP 3n +.RE +.PP \fBKERNEL\fR +.RS 3n Match the name of the event device. -.TP 3n +.RE +.PP \fBSUBSYSTEM\fR +.RS 3n Match the subsystem of the event device. -.TP 3n +.RE +.PP \fBATTR{\fR\fB\fIfilename\fR\fR\fB}\fR +.RS 3n Match sysfs attribute values of the event device. Up to five \fBATTR\fR keys can be specified per rule. Trailing whitespace in the attribute values is ignored, if the specified match value does not contain trailing whitespace itself. Depending on the type of operator, this key is also used to set the value of a sysfs attribute. -.TP 3n +.RE +.PP \fBKERNELS\fR +.RS 3n Search the devpath upwards for a matching device name. -.TP 3n +.RE +.PP \fBSUBSYSTEMS\fR +.RS 3n Search the devpath upwards for a matching device subsystem name. -.TP 3n +.RE +.PP \fBDRIVERS\fR +.RS 3n Search the devpath upwards for a matching device driver name. -.TP 3n +.RE +.PP \fBATTRS{\fR\fB\fIfilename\fR\fR\fB}\fR +.RS 3n Search the devpath upwards for a device with matching sysfs attribute values. Up to five \fBATTRS\fR keys can be specified per rule. All attributes must match on the same device. Trailing whitespace in the attribute values is ignored, if the specified match value does not contain trailing whitespace itself. -.TP 3n +.RE +.PP \fBENV{\fR\fB\fIkey\fR\fR\fB}\fR +.RS 3n Match against the value of an environment variable. Up to five \fBENV\fR keys can be specified per rule. Depending on the type of operator, this key is also used to export a variable to the environment. -.TP 3n +.RE +.PP \fBPROGRAM\fR +.RS 3n Execute external program. The key is true, if the program returns without exit code zero. The whole event environment is available to the executed program. The program's output printed to stdout is available for the RESULT key. -.TP 3n +.RE +.PP \fBRESULT\fR +.RS 3n Match the returned string of the last PROGRAM call. This key can be used in the same or in any later rule after a PROGRAM call. +.RE .PP Most of the fields support a shell style pattern matching. The following pattern characters are supported: -.TP 3n +.PP \fB*\fR +.RS 3n Matches zero, or any number of characters. -.TP 3n +.RE +.PP \fB?\fR +.RS 3n Matches any single character. -.TP 3n +.RE +.PP \fB[]\fR +.RS 3n Matches any single character specified within the brackets. For example, the pattern string 'tty[SR]' would match either 'ttyS' or 'ttyR'. Ranges are also supported within this match with the '\-' character. For example, to match on the range of all digits, the pattern [0\-9] would be used. If the first character following the '[' is a '!', any characters not enclosed are matched. +.RE .PP The following keys can get values assigned: -.TP 3n +.PP \fBNAME\fR +.RS 3n The name of the node to be created, or the name the network interface should be renamed to. Only one rule can set the node name, all later rules with a NAME key will be ignored. -.TP 3n +.RE +.PP \fBSYMLINK\fR +.RS 3n The name of a symlink targeting the node. Every matching rule can add this value to the list of symlinks to be created along with the device node. Multiple symlinks may be specified by separating the names by the space character. -.TP 3n +.RE +.PP \fBOWNER, GROUP, MODE\fR +.RS 3n The permissions for the device node. Every specified value overwrites the compiled\-in default value. -.TP 3n +.RE +.PP \fBATTR{\fR\fB\fIkey\fR\fR\fB}\fR +.RS 3n The value that should be written to a sysfs attribute of the event device. Depending on the type of operator, this key is also used to match against the value of a sysfs attribute. -.TP 3n +.RE +.PP \fBENV{\fR\fB\fIkey\fR\fR\fB}\fR +.RS 3n Export a variable to the environment. Depending on the type of operator, this key is also to match against an environment variable. -.TP 3n +.RE +.PP \fBRUN\fR +.RS 3n Add a program to the list of programs to be executed for a specific device. This can only be used for very short running tasks. Running an event process for a long period of time may block all further events for this or a dependent device. Long running tasks need to be immediately detached from the event process itself. -.TP 3n +.RE +.PP \fBLABEL\fR +.RS 3n Named label where a GOTO can jump to. -.TP 3n +.RE +.PP \fBGOTO\fR +.RS 3n Jumps to the next LABEL with a matching name -.TP 3n +.RE +.PP \fBIMPORT{\fR\fB\fItype\fR\fR\fB}\fR -Import the printed result or the value of a file in environment key format into the event environment. +.RS 3n +Import a set of variables into the event environment, depending on +\fItype\fR: +.RS 3n +.PP +\fBprogram\fR +.RS 3n +Execute an external program specified as the assigned value and import its output, which must be in environment key format. +.RE +.PP +\fBfile\fR +.RS 3n +Import a text file specified as the assigned value, which must be in environment key format. +.RE +.PP +\fBparent\fR +.RS 3n +Import the stored keys from the parent device by reading the database entry of the parent device. The value assigned to +\fBIMPORT{parent}\fR +is used as a filter of key names to import (with the same shell\-style pattern matching used for comparisons). +.RE +.RE +.IP "" 3n +If no option is given, udev will choose between \fBprogram\fR -will execute an external program and read its output. +and \fBfile\fR -will import a text file. If no option is given, udev will determine it from the executable bit of of the file permissions. -.TP 3n +based on the executable bit of of the file permissions. +.RE +.PP \fBWAIT_FOR_SYSFS\fR +.RS 3n Wait for the specified sysfs file of the device to be created. Can be used to fight against kernel sysfs timing issues. -.TP 3n +.RE +.PP \fBOPTIONS\fR +.RS 3n \fBlast_rule\fR stops further rules application. No later rules will have any effect. \fBignore_device\fR @@ -171,6 +259,7 @@ will ignore this event completely. will ignore any later remove event for this device. This may be useful as a workaround for broken device drivers. \fBall_partitions\fR will create the device nodes for all available partitions of a block device. This may be useful for removable media devices where media changes are not detected. +.RE .PP The \fBNAME\fR, @@ -183,58 +272,85 @@ and fields support simple printf\-like string substitutions. The \fBRUN\fR format chars gets applied after all rules have been processed, right before the program is executed. It allows the use of the complete environment set by earlier matching rules. For all other fields, substitutions are applied while the individual rule is being processed. The available substitutions are: -.TP 3n +.PP \fB$kernel\fR, \fB%k\fR +.RS 3n The kernel name for this device. -.TP 3n +.RE +.PP \fB$number\fR, \fB%n\fR +.RS 3n The kernel number for this device. For example, 'sda3' has kernel number of '3' -.TP 3n +.RE +.PP \fB$devpath\fR, \fB%p\fR +.RS 3n The devpath of the device. -.TP 3n +.RE +.PP \fB$id\fR, \fB%b\fR +.RS 3n The name of the device matched while searching the devpath upwards for \fBSUBSYSTEMS\fR, \fBKERNELS\fR, \fBDRIVERS\fR and \fBATTRS\fR. -.TP 3n +.RE +.PP \fB$attr{\fR\fB\fIfile\fR\fR\fB}\fR, \fB%s{\fR\fB\fIfile\fR\fR\fB}\fR +.RS 3n The value of a sysfs attribute found at the device, where all keys of the rule have matched. If the matching device does not have such an attribute, all devices along the chain of parents are searched for a matching attribute. If the attribute is a symlink, the last element of the symlink target is returned as the value. -.TP 3n +.RE +.PP \fB$env{\fR\fB\fIkey\fR\fR\fB}\fR, \fB%E{\fR\fB\fIkey\fR\fR\fB}\fR +.RS 3n The value of an environment variable. -.TP 3n +.RE +.PP \fB$major\fR, \fB%M\fR +.RS 3n The kernel major number for the device. -.TP 3n +.RE +.PP \fB$minor\fR \fB%m\fR +.RS 3n The kernel minor number for the device. -.TP 3n +.RE +.PP \fB$result\fR, \fB%c\fR +.RS 3n The string returned by the external program requested with PROGRAM. A single part of the string, separated by a space character may be selected by specifying the part number as an attribute: \fB%c{N}\fR. If the number is followed by the '+' char this part plus all remaining parts of the result string are substituted: \fB%c{N+}\fR -.TP 3n +.RE +.PP \fB$parent\fR, \fB%P\fR +.RS 3n The node name of the parent device. -.TP 3n +.RE +.PP \fB$root\fR, \fB%r\fR +.RS 3n The udev_root value. -.TP 3n +.RE +.PP \fB$tempnode\fR, \fB%N\fR +.RS 3n The name of a created temporary device node to provide access to the device from a external program before the real node is created. -.TP 3n +.RE +.PP \fB%%\fR +.RS 3n The '%' character itself. -.TP 3n +.RE +.PP \fB$$\fR +.RS 3n The '$' character itself. +.RE .PP The count of characters to be substituted may be limited by specifying the format length value. For example, '%3s{file}' will only insert the first three characters of the sysfs attribute -.\" end of SS subsection "Rules files" .SH "AUTHOR" .PP Written by Greg Kroah\-Hartman @@ -341,11 +341,37 @@ <varlistentry> <term><option>IMPORT{<replaceable>type</replaceable>}</option></term> <listitem> - <para>Import the printed result or the value of a file in environment key - format into the event environment. <option>program</option> will execute an - external program and read its output. <option>file</option> will import a - text file. If no option is given, udev will determine it from the executable - bit of of the file permissions.</para> + <para>Import a set of variables into the event environment, + depending on <replaceable>type</replaceable>:</para> + <variablelist> + <varlistentry> + <term><option>program</option></term> + <listitem> + <para>Execute an external program specified as the assigned value and + import its output, which must be in environment key format.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>file</option></term> + <listitem> + <para>Import a text file specified as the assigned value, which must be in + environment key format.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>parent</option></term> + <listitem> + <para>Import the stored keys from the parent device by reading + the database entry of the parent device. The value assigned to + <option>IMPORT{parent}</option> is used as a filter of key names + to import (with the same shell-style pattern matching used for + comparisons).</para> + </listitem> + </varlistentry> + </variablelist> + <para>If no option is given, udev will choose between <option>program</option> + and <option>file</option> based on the executable bit of of the file + permissions.</para> </listitem> </varlistentry> @@ -1,6 +1,6 @@ .\" Title: udevd .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: August 2005 .\" Manual: udevd, udevcontrol .\" Source: udev @@ -21,35 +21,51 @@ udevd \- event managing daemon .PP udevd listens to kernel uevents and passes the incoming events to udev. It ensures the right event order and takes care, that events for child devices are delayed until the parent has finished the device handling. .SH "OPTIONS" -.TP 3n +.PP \fB\-\-daemon\fR +.RS 3n Detach and run in the background. -.TP 3n +.RE +.PP \fB\-\-debug\-trace\fR +.RS 3n Run all events completely serialized. This may be useful if udev triggers actions or loads kernel modules which cause problems and a slow but continiuous operation is needed, where no events are processed in parallel. -.TP 3n +.RE +.PP \fB\-\-verbose\fR +.RS 3n Print log messages to stdout. -.TP 3n +.RE +.PP \fB\-\-help\fR +.RS 3n Print usage. -.TP 3n +.RE +.PP \fBlog_priority=\fR\fB\fIvalue\fR\fR +.RS 3n udevcontrol can dynamically set the log level of udevd. Valid values are the numerical syslog priorities or their textual representations: \fBerr\fR, \fBinfo\fR and \fBdebug\fR. -.TP 3n +.RE +.PP \fBstop_exec_queue\fR +.RS 3n udevcontrol stops the execution of events from udevd. -.TP 3n +.RE +.PP \fBstart_exec_queue\fR +.RS 3n udevcontrol starts the execution of events from udevd. +.RE .SH "ENVIRONMENT" -.TP 3n +.PP \fBUDEV_LOG\fR +.RS 3n Overrides the syslog priority specified in the config file. +.RE .SH "AUTHOR" .PP Written by Kay Sievers diff --git a/udevinfo.8 b/udevinfo.8 index 65c4e3b3de..7ba7e70128 100644 --- a/udevinfo.8 +++ b/udevinfo.8 @@ -1,6 +1,6 @@ .\" Title: udevinfo .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: August 2005 .\" Manual: udevinfo .\" Source: udev @@ -19,8 +19,9 @@ udevinfo \- query device information from the udev database .PP udevinfo queries the udev database for device information stored in the udev database. It can also query the properties of a device from its sysfs representation to help creating udev rules that match this device. .SH "OPTIONS" -.TP 3n +.PP \fB\-\-query=\fR\fB\fItype\fR\fR +.RS 3n Query the database for specified type of device data. It needs the \fB\-\-path\fR or @@ -31,29 +32,42 @@ to identify the specified device. Valid queries are: \fBpath\fR, \fBenv\fR, \fBall\fR. -.TP 3n +.RE +.PP \fB\-\-path=\fR\fB\fIdevpath\fR\fR +.RS 3n The devpath of the device to query. -.TP 3n +.RE +.PP \fB\-\-name=\fR\fB\fInode\fR\fR +.RS 3n The name of the device node or a symlink to query -.TP 3n +.RE +.PP \fB\-\-root\fR +.RS 3n The udev root directory: \fI/dev\fR. If used in conjunction with a \fBname\fR or \fBsymlink\fR query, the query returns the absolute path including the root directory. -.TP 3n +.RE +.PP \fB\-\-attribute\-walk\fR +.RS 3n Print all sysfs properties of the specified device that can be used in udev rules to match the specified device. It prints all devices along the chain, up to the root of sysfs that can be used in udev rules. -.TP 3n +.RE +.PP \fB\-\-export\fR +.RS 3n Export the content of the udev database. -.TP 3n +.RE +.PP \fB\-\-help\fR +.RS 3n Print help text. +.RE .SH "AUTHOR" .PP Written by Kay Sievers diff --git a/udevmonitor.8 b/udevmonitor.8 index 4577aef95c..a43ea405bf 100644 --- a/udevmonitor.8 +++ b/udevmonitor.8 @@ -1,6 +1,6 @@ .\" Title: udevmonitor .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: August 2005 .\" Manual: udevmonitor .\" Source: udev @@ -19,9 +19,11 @@ udevmonitor \- print the kernel and udev event sequence to the console .PP udevmonitor listens to the kernel uevents and events send out by a udev rule and prints the devpath of the event to the console. It can be used analyze to the event timing by comparing the timestamps of the kernel uevent with the udev event. .SH "OPTIONS" -.TP 3n +.PP \fB\-\-env\fR +.RS 3n Print the complete environment for all events. Can be used to compare the kernel supplied and the udev added environment values. +.RE .SH "AUTHOR" .PP Written by Kay Sievers diff --git a/udevsettle.8 b/udevsettle.8 index 2a51948d74..bf0cb06ada 100644 --- a/udevsettle.8 +++ b/udevsettle.8 @@ -1,6 +1,6 @@ .\" Title: udevsettle .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: March 2006 .\" Manual: udevsettle .\" Source: udev @@ -19,13 +19,17 @@ udevsettle \- wait until queued kernel/udev events are handled .PP Waits watching the udev event queue and exits if all current events are handled. .SH "OPTIONS" -.TP 3n +.PP \fB\-\-timeout=\fR\fB\fIseconds\fR\fR +.RS 3n maximum seconds to wait for the queue to become empty. +.RE .SH "ENVIRONMENT" -.TP 3n +.PP \fBUDEV_LOG\fR +.RS 3n Overrides the syslog priority specified in the config file. +.RE .SH "AUTHOR" .PP Written by Kay Sievers diff --git a/udevstart.8 b/udevstart.8 index 9f18c05d07..3357c89d73 100644 --- a/udevstart.8 +++ b/udevstart.8 @@ -1,6 +1,6 @@ .\" Title: udevstart .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: August 2005 .\" Manual: udevstart .\" Source: udev diff --git a/udevtest.8 b/udevtest.8 index 9e11f93b24..bb5e98c078 100644 --- a/udevtest.8 +++ b/udevtest.8 @@ -1,6 +1,6 @@ .\" Title: udevtest .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: August 2005 .\" Manual: udevtest .\" Source: udev diff --git a/udevtrigger.8 b/udevtrigger.8 index 4525aeeddf..300f8e8984 100644 --- a/udevtrigger.8 +++ b/udevtrigger.8 @@ -1,6 +1,6 @@ .\" Title: udevtrigger .\" Author: -.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/> +.\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/> .\" Date: March 2006 .\" Manual: udevtrigger .\" Source: udev @@ -19,31 +19,47 @@ udevtrigger \- request kernel devices events for coldplug .PP Trigger kernel device uevents to replay missing events at system coldplug. .SH "OPTIONS" -.TP 3n +.PP \fB\-\-verbose\fR +.RS 3n Print the list of devices which will be triggered. -.TP 3n +.RE +.PP \fB\-\-dry\-run\fR +.RS 3n Do not actually trigger the event. -.TP 3n +.RE +.PP \fB\-\-retry\-failed\fR +.RS 3n Trigger only the events which are failed during a previous run. -.TP 3n +.RE +.PP \fB\-\-subsystem\-match=\fR\fB\fIsubsystem\fR\fR +.RS 3n Trigger events for devices which belong to a matching subsystem. This option can be specified multiple times and supports shell style pattern matching. -.TP 3n +.RE +.PP \fB\-\-subsystem\-nomatch=\fR\fB\fIsubsystem\fR\fR +.RS 3n Do not trigger events for devices which belong to a matching subsystem. This option can be specified multiple times and supports shell style pattern matching. -.TP 3n +.RE +.PP \fB\-\-attr\-match=\fR\fB\fIattribute=value\fR\fR +.RS 3n Trigger events for devices with a matching sysfs attribute. If a value is specified along with the attribute name, the content of the attribute is matched against the given value using shell style pattern matching. If no value is specified, the existence of the sysfs attribute is checked. This option can be specified multiple times. -.TP 3n +.RE +.PP \fB\-\-attr\-nomatch\fR\fB\fIattribute=value\fR\fR +.RS 3n Do not trigger events for devices with a matching sysfs attribute. If a value is specified along with the attribute name, the content of the attribute is matched against the given value using shell style pattern matching. If no value is specified, the existence of the sysfs attribute is checked. This option can be specified multiple times. +.RE .SH "ENVIRONMENT" -.TP 3n +.PP \fBUDEV_LOG\fR +.RS 3n Overrides the syslog priority specified in the config file. +.RE .SH "AUTHOR" .PP Written by Kay Sievers |