1.\" 2.\" Copyright (c) 2002 M. Warner Losh <imp@FreeBSD.org> 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. The name of the author may not be used to endorse or promote products 10.\" derived from this software without specific prior written permission. 11.\" 12.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 13.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 14.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 15.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 16.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 17.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 18.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 19.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 20.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 21.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 22.\" SUCH DAMAGE. 23.\" 24.\" $FreeBSD$ 25.\" 26.\" The section on comments was taken from named.conf.5, which has the 27.\" following copyright: 28.\" Copyright (c) 1999-2000 by Internet Software Consortium 29.\" 30.\" Permission to use, copy, modify, and distribute this software for any 31.\" purpose with or without fee is hereby granted, provided that the above 32.\" copyright notice and this permission notice appear in all copies. 33.\" 34.\" THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS 35.\" ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES 36.\" OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE 37.\" CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 38.\" DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 39.\" PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 40.\" ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 41.\" SOFTWARE. 42.\" 43.Dd October 12, 2020 44.Dt DEVD.CONF 5 45.Os 46.Sh NAME 47.Nm devd.conf 48.Nd configuration file for 49.Xr devd 8 50.Sh DESCRIPTION 51.Ss General Syntax 52A 53.Xr devd 8 54configuration consists of two general features, statements 55and comments. 56All statements end with a semicolon. 57Many statements can contain substatements, which are also 58terminated with a semicolon. 59.Pp 60The following statements are supported: 61.Bl -tag -width ".Ic options" 62.It Ic attach 63Specifies various matching criteria and actions to perform when 64a newly attached device matches said criteria. 65.It Ic detach 66Specifies various matching criteria and actions to perform when 67a newly detached device matches said criteria. 68.It Ic nomatch 69Specifies various matching criteria and actions to perform when 70no device driver currently loaded in the kernel claims a (new) 71device. 72.It Ic notify 73Specifies various matching criteria and actions to perform when the kernel 74sends an event notification to userland. 75.It Ic options 76Specifies various options and parameters for the operation of 77.Xr devd 8 . 78.El 79.Pp 80Statements may occur in any order in the configuration file, and may be 81repeated as often as required. 82Further details on the syntax and meaning of each statement and their 83substatements are explained below. 84.Pp 85Each statement, except 86.Ic options 87has a priority (an arbitrary number) associated with it, where 88.Ql 0 89is defined as the lowest priority. 90If two statements match the same event, only the action of the statement with 91highest priority will be executed. 92In this way generic statements can be overridden for devices or 93notifications that require special attention. 94.Pp 95The general syntax of a statement is: 96.Bd -literal -offset indent 97statement priority { 98 substatement "value"; 99 ... 100 substatement "value"; 101}; 102.Ed 103.Ss Sub-statements 104The following sub-statements are supported within the 105.Ic options 106statement. 107.Bl -tag -width ".Ic directory" 108.It Ic directory Qq Ar /some/path ; 109Adds the given directory to the list of directories from which 110.Xr devd 8 111will read all files named "*.conf" as further 112configuration files. 113Any number of 114.Ic directory 115statements can be used. 116.It Ic pid-file Qq Pa /var/run/devd.pid ; 117Specifies PID file. 118.It Ic set Ar regexp-name Qq Ar (some|regexp) ; 119Creates a regular expression and assigns it to the variable 120.Ar regexp-name . 121The variable is available throughout the rest of 122the configuration file. 123If the string begins with 124.Ql \&! , 125it matches if the regular expression formed by the rest of the string 126does not match. 127All regular expressions have an implicit 128.Ql ^$ 129around them. 130.El 131.Pp 132The following sub-statements are supported within the 133.Ic attach 134and 135.Ic detach 136statements. 137.Bl -tag -width ".Ic directory" 138.It Ic action Qq Ar command ; 139Command to execute upon a successful match. 140Example 141.Dq Li "/etc/pccard_ether $device-name start" . 142.It Ic class Qq Ar string ; 143This is shorthand for 144.Dq Ic match Qo Li class Qc Qq Ar string . 145.It Ic device-name Qq string ; 146This is shorthand for 147.Dq Ic match Qo Li device-name Qc Qq Ar string . 148This matches a device named 149.Ar string , 150which is allowed to be a regular expression or a variable previously created 151containing a regular expression. 152The 153.Dq Li device-name 154variable 155is available for later use with the 156.Ic action 157statement. 158.It Ic match Qo Ar variable Qc Qq Ar value ; 159Matches the content of 160.Ar value 161against 162.Ar variable ; 163the content of 164.Ar value 165may be a regular expression. 166Not required during 167.Ic attach 168nor 169.Ic detach 170events since the 171.Ic device-name 172statement takes care of all device matching. 173For a partial list of variables, see below. 174.It Ic media-type Qq Ar string ; 175For network devices, 176.Ic media-type 177will match devices that have the given media type. 178Valid media types are: 179.Dq Li Ethernet , 180.Dq Li Tokenring , 181.Dq Li FDDI , 182.Dq Li 802.11 , 183and 184.Dq Li ATM . 185.It Ic subdevice Qq Ar string ; 186This is shorthand for 187.Dq Ic match Qo Li subdevice Qc Qq Ar string . 188.El 189.Pp 190The following sub-statements are supported within the 191.Ic nomatch 192statement. 193.Bl -tag -width ".Ic directory" 194.It Ic action Qq Ar command ; 195Same as above. 196.It Ic match Qo Ar variable Qc Qq Ar value ; 197Matches the content of 198.Ar value 199against 200.Ar variable ; 201the content of 202.Ar value 203may be a regular expression. 204For a partial list of variables, see below. 205.El 206.Pp 207The following sub-statements are supported within the 208.Ic notify 209statement. 210The 211.Dq Li notify 212variable is available inside this statement and contains, a value, depending 213on which system and subsystem that delivered the event. 214.Bl -tag -width ".Ic directory" 215.It Ic action Qq Ar command ; 216Command to execute upon a successful match. 217Example 218.Dq Li "/etc/rc.d/power_profile $notify" . 219.It Ic match Qo Ar system | subsystem | type | notify Qc Qq Ar value ; 220Any number of 221.Ic match 222statements can exist within a 223.Ic notify 224statement; 225.Ar value 226can be either a fixed string or a regular expression. 227Below is a list of available systems, subsystems, and types. 228.It Ic media-type Qq Ar string ; 229See above. 230.El 231.Ss Variables that can be used with the match statement 232A partial list of variables and their possible values that can be used together 233with the 234.Ic match 235statement. 236The variables are published by the bus based on characteristics of the device 237that generated the event (for device events). 238Variables for other classes of events are dependent on those events. 239.Pp 240.Bl -tag -width ".Li manufacturer" -compact 241.It Ic Variable 242.Ic Description 243.It Li * 244The entire message from the current event. 245.It Li _ 246The entire message from the current event, after the initial type character. 247.It Li timestamp 248The time this event was processed, in seconds since 1970 dot fraction. 249.It Li bus 250Device name of parent bus. 251.It Li cdev 252Device node path if one is created by the 253.Xr devfs 5 254filesystem. 255.It Li class 256Device class. 257.It Li comm 258Executable name (kernel). 259.It Li core 260Path to core file (kernel). 261.It Li device 262Device ID. 263.It Li devclass 264Device Class (USB). 265.It Li devsubclass 266Device Sub-class (USB). 267.It Li device-name 268Name of attached/detached device. 269.It Li endpoints 270Endpoint count (USB). 271.It Li function 272Card functions. 273.It Li interface 274Interface ID (USB). 275.It Li intclass 276Interface Class (USB). 277.It Li intprotocol 278Interface Protocol (USB). 279.It Li intsubclass 280Interface Sub-class (USB). 281.It Li jail 282Jail name for the process triggering the rule (RCTL). 283.It Li mode 284Peripheral mode (USB). 285.It Li notify 286Match the value of the 287.Dq Li notify 288variable. 289.It Li parent 290Parent device. 291.It Li pid 292PID of the process triggering the rule (RCTL). 293.It Li port 294Hub port number (USB). 295.It Li product 296Product ID (USB). 297.It Li release 298Hardware revision (USB). 299.It Li ruid 300Real UID of the process triggering the rule (RCTL). 301.It Li rule 302Rule (RCTL). 303.It Li sernum 304Serial Number (USB). 305.It Li slot 306Card slot. 307.It Li subvendor 308Sub-vendor ID (PCI). 309.It Li subdevice 310Sub-device ID (PCI). 311.It Li subsystem 312Matches a subsystem of a system, see below. 313.It Li system 314Matches a system type, see below. 315.It Li type 316Type of notification, see below. 317.It Li vendor 318Vendor ID. 319.El 320.Ss Notify matching 321A partial list of systems, subsystems, and types used within the 322.Ic notify 323mechanism. 324.\" 325.\" Please keep these tables sorted. Also, please use the same parameters 326.\" for each of the tables so that things line up in columns nicely. 327.\" Please do not omit the type column for notifiers that omit it. 328.Pp 329.Bl -column "System" "Subsystem" "1234567" -compact 330.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 331.It Li ACPI Ta Ta Ta 332Events related to the ACPI Subsystem. 333.It Li ACPI Ta Li ACAD Ta Ta 334AC line state ($notify=0x00 is offline, 0x01 is online). 335.It Li ACPI Ta Li Button Ta Ta 336Button state ($notify=0x00 is power, 0x01 is sleep). 337.It Li ACPI Ta Li CMBAT Ta Ta 338Battery events. 339.It Li ACPI Ta Li Dock Ta Ta 340Dock state ($notify=0x00 is undocked, 0x01 is docked). 341.It Li ACPI Ta Li Lid Ta Ta 342Lid state ($notify=0x00 is closed, 0x01 is open). 343.It Li ACPI Ta Li PROCESSOR Ta Ta 344Processor state/configuration ($notify=0x81 is a change in available Cx states). 345.It Li ACPI Ta Li Resume Ta Ta 346Resume notification. 347.It Li ACPI Ta Li Suspend Ta Ta 348Suspend notification. 349.It Li ACPI Ta Li Thermal Ta Ta 350Thermal zone events. 351.El 352.Pp 353.Bl -column "System" "Subsystem" "1234567" -compact 354.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 355.It Li AEON Ta Li power Ta Li press Ta 356The power button on an Amiga has been pressed. 357.El 358.Pp 359.Bl -column "System" "Subsystem" "1234567" -compact 360.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 361.It Li CAM Ta Ta Ta 362Events related to the 363.Xr cam 4 364system. 365.It Li CAM Ta Li periph Ta Ta 366Events related to peripheral devices. 367.It Li CAM Ta Li periph Ta Li error Ta 368Generic errors. 369.It Li CAM Ta Li periph Ta Li timeout Ta 370Command timeouts. 371.El 372.Pp 373.Bl -column "System" "Subsystem" "1234567" -compact 374.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 375.It Li CARP Ta Ta Ta 376Events related to the 377.Xr carp 4 378protocol. 379.It CARP Ta Ar vhid@inet Ta Ta 380The 381.Dq subsystem 382contains the actual CARP vhid and the name of the network interface 383on which the event took place. 384.It CARP Ta Ar vhid@inet Ta MASTER Ta 385Node become the master for a virtual host. 386.It CARP Ta Ar vhid@inet Ta BACKUP Ta 387Node become the backup for a virtual host. 388.El 389.Pp 390.Bl -column "System" "Subsystem" "1234567" -compact 391.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 392.It Li coretemp Ta Ta Ta 393Events related to the 394.Xr coretemp 4 395device. 396.It Li coretemp Ta Li Thermal Ta Ta 397Notification that the CPU core has reached critical temperature. 398.It Li coretemp Ta Li Thermal Ta Li temperature Ta 399String containing the temperature of the core that has become too hot. 400.El 401.Pp 402.Bl -column "System" "Subsystem" "1234567" -compact 403.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 404.It Li DEVFS 405.It Li DEVFS Ta Li CDEV Ta Li CREATE Ta 406The 407.Xr devfs 5 408node is created. 409.It Li DEVFS Ta Li CDEV Ta Li DESTROY Ta 410The 411.Xr devfs 5 412node is destroyed. 413.El 414.Pp 415.Bl -column "System" "Subsystem" "1234567" -compact 416.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 417.It Li ETHERNET Ta Ar inet Ta IFATTACH Ta 418Notification when the default VNET instance of the 419.Em inet 420interface is attached. 421.El 422.Pp 423.Bl -column "System" "Subsystem" "1234567" -compact 424.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 425.It Li GEOM Ta Ta Ta 426Events related to the 427.Xr geom 4 428framework. 429The difference compared to 430.Li DEVFS 431is that 432.Li GEOM 433only includes disk-like devices. 434.It Li GEOM Ta Li DEV Ta Li CREATE Ta 435A 436.Xr geom 4 437provider is created. 438.It Li GEOM Ta Li DEV Ta Li DESTROY Ta 439A 440.Xr geom 4 441provider is destroyed. 442.It Li GEOM Ta Li DEV Ta Li GEOM::physpath Ta 443The physical path of a device has changed. 444.It Li GEOM Ta Li DEV Ta Li GEOM::rotation_rate Ta 445The rotation rate of the disk has changed. 446.It Li GEOM Ta Li DEV Ta Li MEDIACHANGE Ta 447Physical media has changed. 448.It Li GEOM Ta Li DEV Ta Li SIZECHANGE Ta 449A 450.Xr geom 4 451provider size has changed. 452.El 453.Pp 454.Bl -column "System" "Subsystem" "1234567" -compact 455.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 456.It Li IFNET 457.It Li IFNET Ta Em inet Ta Ta 458The 459.Dq subsystem 460is the actual name of the network interface on which the event 461took place. 462.It Li IFNET Ta Em inet Ta Li LINK_UP Ta 463Carrier status changed to UP. 464.It Li IFNET Ta Em inet Ta Li LINK_DOWN Ta 465Carrier status changed to DOWN. 466.It Li IFNET Ta Em inet Ta Li ATTACH Ta 467The network interface is attached to the system. 468.It Li IFNET Ta Em inet Ta Li DETACH Ta 469The network interface is detached from the system. 470.El 471.Pp 472.Bl -column "System" "Subsystem" "1234567" -compact 473.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 474.It Li kern Ta Li power Ta Li resume Ta 475Notification that the system has woken from the suspended state. 476Note: this notification is deprecated and will be removed in 477.Fx 14.0 . 478.El 479.Pp 480.Bl -column "System" "Subsystem" "1234567" -compact 481.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 482.It Li kernel Ta Li signal Ta Li coredump Ta 483Notification that a process has crashed and dumped core. 484.It Li kernel Ta Li power Ta Li resume Ta 485Notification that the system has woken from the suspended state. 486.El 487.Pp 488.Bl -column "System" "Subsystem" "1234567" -compact 489.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 490.It Li PMU Ta Ta Ta 491Notification of events from various types of Power Management Units. 492.It Li PMU Ta Li "AC" Ta Ta 493Notifications of AC power related events. 494.It Li PMU Ta Li "AC" Ta Li overvoltage Ta 495An over-voltage condition was detected on the AC power line. 496.It Li PMU Ta Li "AC" Ta Li plugged Ta 497Power has been applied to the AC power line. 498.It Li PMU Ta Li "AC" Ta Li unplugged Ta 499Power has been removed from the AC power line. 500.It Li PMU Ta Li Battery Ta Ta 501.It Li PMU Ta Li Battery Ta absent Ta 502Battery is no longer absent. 503.It Li PMU Ta Li Battery Ta charged Ta 504The battery has become charged. 505.It Li PMU Ta Li Battery Ta charging Ta 506The battery has started charging. 507.It Li PMU Ta Li Battery Ta disconnected Ta 508The battery has been disconnected. 509.It Li PMU Ta Li Battery Ta high-temp Ta 510The battery reported a temperature over the limit. 511.It Li PMU Ta Li Battery Ta low-temp Ta 512The battery reported a temperature under the limit. 513.It Li PMU Ta Li Battery Ta plugged Ta 514The battery has become plugged (eg connected). 515.It Li PMU Ta Li Battery Ta shutdown-threshold Ta 516The power in the battery has fallen below the shutdown threshold. 517.It Li PMU Ta Li Battery Ta warning-threshold Ta 518The power in the battery has fallen below the warn the user threshold. 519.It Li PMU Ta Li Button Ta pressed Ta 520A button on a 521.Xr adb 4 522or 523.Xr pmu 4 524has been pressed. 525.It Li PMU Ta Li keys Ta Ta 526One of the keys on the 527.Xr adb 4 528keyboard has been pressed. 529.It Li PMU Ta Li keys Ta brightness Ta 530A brightness level change has been requested. 531Direction is in the $notify variable. 532.It Li PMU Ta Li keys Ta mute Ta 533The mute key 534.It Li PMU Ta Li keys Ta volume Ta 535A volume level change has been requested. 536Direction is in the $notify variable. 537.It Li PMU Ta Li keys Ta eject Ta 538An ejection has been requested. 539.It Li PMU Ta Li lid Ta close Ta 540The 541.Xr pmc 4 542device has detected the lid closing. 543.It Li PMU Ta Li lid Ta open Ta 544The 545.Xr pmc 4 546device has detected the lid openinging. 547.It Li PMU Ta Li POWER Ta ACLINE Ta 548The 549.Xr pmc 4 550device has deteted an AC line state ($notify=0x00 is offline, 0x01 is online). 551.It Li PMU Ta Li USB Ta overvoltage Ta 552An over-voltage condition on the power lines for the USB power pins. 553.It Li PMU Ta Li USB Ta plugged Ta 554A device has been plugged into a USB device. 555.It Li PMU Ta Li USB Ta undervoltage Ta 556An under-voltage condition on the power lines for the USB power pins. 557.It Li PMU Ta Li USB Ta unplugged Ta 558A device has been unplugged into a USB device. 559.El 560.Pp 561.Bl -column "System" "Subsystem" "1234567" -compact 562.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 563.It Li RCTL Ta Ta Ta 564Events related to the 565.Xr rctl 8 566framework. 567.It Li RCTL Ta Li rule Ta Li matched Ta 568A rule with action specified as "devctl" was triggered. 569.El 570.Pp 571.Bl -column "System" "Subsystem" "1234567" -compact 572.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 573.It Li USB Ta Ta Ta 574Events related to the USB subsystem. 575.It Li USB Ta Li DEVICE Ta Li ATTACH Ta 576USB device is attached to the system. 577.It Li USB Ta Li DEVICE Ta Li DETACH Ta 578USB device is detached to the system. 579.It Li USB Ta Li INTERFACE Ta Li ATTACH Ta 580USB interface is attached to a device. 581.It Li USB Ta Li INTERFACE Ta Li DETACH Ta 582USB interface is detached from a device. 583.El 584.Pp 585.Bl -column "System" "Subsystem" "1234567" -compact 586.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 587.It Li VFS Ta Ta Ta 588Events from the vfs system. 589.It Li VFS Ta Li FS Ta Ta 590Events that change what is mounted to the system. 591.It Li VFS Ta Li FS Ta Li MOUNT Ta 592Notification of a filesystem is mounted for the first time. 593.It Li VFS Ta Li FS Ta Li REMOUNT Ta 594Notification of a filesystem is remounted (whether or not the options actually change). 595.It Li VFS Ta Li FS Ta Li UNMOUNT Ta 596Notification of a filesystem being unmounted. 597.El 598.Pp 599.Bl -column "System" "Subsystem" "1234567" -compact 600.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description" 601.It Li ZFS Ta ZFS Ta Ta 602Events about the ZFS subsystem. 603See 604.Xr zfsd 8 605and 606.Pa /etc/devd/zfs.conf 607for details. 608.El 609.Pp 610.\" 611.\" End of tables 612.\" 613A link state change to UP on the interface 614.Dq Li fxp0 615would result in the following notify event: 616.Bd -literal -offset indent 617system=IFNET subsystem=fxp0 type=LINK_UP 618.Ed 619.Pp 620An AC line state change to 621.Dq offline 622would result in the following event: 623.Bd -literal -offset indent 624system=ACPI subsystem=ACAD notify=0x00 625.Ed 626.Ss Comments 627Comments may appear anywhere that whitespace may appear in a 628configuration file. 629To appeal to programmers of all kinds, they can 630be written in C, C++, or shell/Perl constructs. 631.Pp 632C-style comments start with the two characters 633.Ql /* 634(slash, star) and end with 635.Ql */ 636(star, slash). 637Because they are completely delimited with these characters, 638they can be used to comment only a portion of a line or to span 639multiple lines. 640.Pp 641C-style comments cannot be nested. 642For example, the following is 643not valid because the entire comment ends with the first 644.Ql */ : 645.Bd -literal -offset indent 646/* This is the start of a comment. 647 This is still part of the comment. 648/* This is an incorrect attempt at nesting a comment. */ 649 This is no longer in any comment. */ 650.Ed 651.Pp 652C++-style comments start with the two characters 653.Ql // 654(slash, slash) and continue to the end of the physical line. 655They cannot be continued across multiple physical lines; to have 656one logical comment span multiple lines, each line must use the 657.Ql // 658pair. 659For example: 660.Bd -literal -offset indent 661// This is the start of a comment. The next line 662// is a new comment, even though it is logically 663// part of the previous comment. 664.Ed 665.Ss Notes on Variable Expansion 666To prevent issues with special shell characters, the following happens for each 667variable 668.Ic $foo . 669.Bl -enum 670.It 671The characters 672.Dq $' 673are inserted. 674.It 675The string 676.Dq $foo 677is removed. 678.It 679The value of the 680.Ic foo 681variable is inserted into the buffer with all single quote characters 682prefixed by a backslash. 683.El 684.Pp 685See 686.Xr sh 1 687for what this construct means. 688It is safe in all context, except one: inside single quotes. 689If foo=meta and bar=var, then a rule like the following: 690.Bd -literal -offset indent -compact 691action "echo '$foo $bar'"; 692.Ed 693will be presented to the shell via 694.Xr system 3 695as 696.Bd -literal -offset indent -compact 697echo '$'meta' $'var'' 698.Ed 699which produces the following output: 700.Bd -literal -offset indent -compact 701$meta $var 702.Ed 703as its output. 704This is an unanticipated result. 705A future version of this software will change this behavior. 706Users are discouraged from using single quotes inside 707.Ic action 708value without due care. 709.Pp 710The above should be written as 711.Bd -literal -offset indent -compact 712action "echo $foo' '$bar" 713.Ed 714to produce a single argument to echo. 715Given the above expansion, juxtaposing bare variables with 716single quote expressions will produce the right output, 717regardless of the value of the variable. 718.Sh FILES 719.Bl -tag -width ".Pa /etc/devd.conf" -compact 720.It Pa /etc/devd.conf 721The 722.Xr devd 8 723configuration file. 724.El 725.Sh EXAMPLES 726.Bd -literal 727# 728# This will catch link down events on the interfaces fxp0 and ath0 729# 730notify 0 { 731 match "system" "IFNET"; 732 match "subsystem" "(fxp0|ath0)"; 733 match "type" "LINK_DOWN"; 734 action "logger $subsystem is DOWN"; 735}; 736 737# 738# Match lid open/close events 739# These can be combined to a single event, by passing the 740# value of $notify to the external script. 741# 742notify 0 { 743 match "system" "ACPI"; 744 match "subsystem" "Lid"; 745 match "notify" "0x00"; 746 action "logger Lid closed, we can sleep now!"; 747}; 748 749notify 0 { 750 match "system" "ACPI"; 751 match "subsystem" "Lid"; 752 match "notify" "0x01"; 753 action "logger Lid opened, the sleeper must awaken!"; 754}; 755 756# 757# Match a USB device type 758# 759notify 0 { 760 match "system" "USB"; 761 match "subsystem" "INTERFACE"; 762 match "type" "ATTACH"; 763 match "intclass" "0x0e"; 764 action "logger USB video device attached"; 765}; 766 767# 768# Try to configure ath and iwn devices with pccard_ether 769# as they are attached. 770# 771attach 0 { 772 device-name "(ath|iwn)[0-9]+"; 773 action "/etc/pccard_ether $device-name start"; 774}; 775 776# 777# Stop ath and iwn devices as they are detached from 778# the system. 779# 780detach 0 { 781 device-name "(ath|iwn)[0-9]+"; 782 action "/etc/pccard_ether $device-name stop"; 783}; 784.Ed 785.Pp 786The installed 787.Pa /etc/devd.conf 788has many additional examples. 789.Sh SEE ALSO 790.Xr cam 4 , 791.Xr coretemp 4 , 792.Xr devfs 5 , 793.Xr re_format 7 , 794.Xr devd 8 795.Sh BUGS 796The variable expansion's interaction with single quotes is 797suboptimal and surprising. 798