alsactl_init man page on aLinux

Man page or keyword search:  
man Server   7435 pages
apropos Keyword Search (all sections)
Output format
aLinux logo
[printable version]

ALSACTL_INIT(7)			 alsactl init		       ALSACTL_INIT(7)

NAME
       alsactl init - alsa control management - initialization

DESCRIPTION
       "alsactl init" provides soundcard specific initialization.

CONFIGURATION
       All "alsactl init" configuration files are placed in
       /usr/share/alsa/init/ directory. The top level configuration file is
       /usr/share/alsa/init/00main. The default top-level file can be also
       specified using -i or --initfile parameter for the alsactl tool. Every
       file consists of a set of lines of text. All empty lines or lines
       beginning with '#' will be ignored.

   Rules files
       The "alsactl init" rules are read from the files located in the
       /usr/share/alsa/init/*. The top level configuration file is
       /usr/share/alsa/init/00main. 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 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:

       == Compare for equality.

       != Compare for non-equality.

       =  Assign a value to a key. Keys that represent a list, are reset and
	  only this single value is assigned.

       += Add the value to a key that holds a list of entries.

       := Assign a value to a key finally; disallow any later changes, which
	  may be used to prevent changes by any later rules.

       The following key names can be used to match against device properties:

       CARDINDEX
	  Match the card index of the ALSA driver.

       CTL{attribute}
	  Set or test universal control attribute. Possible attributes:

	  numid
	     Numeric control identification.

	  iface, interface
	     Control interface name (CARD, HWEDEP, MIXER, PCM, RAWMIDI, TIMER,
	     SEQUENCER)

	  subdev, subdevice
	     Subdevice number.

	  name
	     Control name

	  index
	     Control index

	  type
	     Control type (BOOLEAN, INTEGER, INTEGER64, ENUMERATED, BYTES,
	     IEC958)

	  attr, attribute
	     Attributes (stored in a string - use match characters * and ?):

	     r	control is readable

	     w	control is writable

	     v	control is volatile

	     i	control is inactive

	     l	control is locked

	     R	control is TLV readable

	     W	control is TLV writable

	     C	control is TLV commandable

	     o	process is owner of this control

	     u	control created in user space

	  owner
	     Control owner process PID number

	  count
	     Control count of values

	  min
	     Value range - minimum value

	  max
	     Value range - maximum value

	  step
	     Value range - step value

	  dBmin
	     Value range - minimum dB value

	  dBmax
	     Value range - maximum dB value

	  items
	     Enumerated value - number of text items

	  enums
	     Enumerated value - list of text names stored between '|'
	     character

	  value
	     Value of control stored to a string delimited by comma (,).

	  do_search
	     Search for a control. Value "1" is returned if a control was
	     found. The CTL{name} key might contain match characters * and ?.
	     An control index might be specified as first argument starting
	     from zero (e.g. CTL{do_search 2}="1").

	  do_count
	     Search for a controls and return total count of matched ones. The
	     CTL{name} key might contain match characters * and ?.

       CONFIG{sysfs_device}
	  The relative path to sysfs subsystem specifying the root directory
	  of a soundcard device. Usually, it should be set to
	  "/class/sound/card$cardinfo{card}/device".

       ATTR{filename}
	  Match sysfs attribute values of the soundcard device. The relative
	  path to sysfs tree must be defined by CONFIG{sysfs_device} key.
	  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.

       ENV{key}
	  Match against the value of an environment variable. Up to five ENV
	  keys can be specified per rule. Depending on the type of operator,
	  this key is also used to export a variable to the environment.

       PROGRAM
	  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.

	  Several buildin commands are available:

	  __ctl_search
	     Search for a control. The CTL{name} key might contain match
	     characters * and ?. An control index might be specified as first
	     argument starting from zero (e.g. PROGRAM="__ctl_search 2").

	  __ctl_count
	     Search for a controls and return total count of matched ones. The
	     CTL{name} key might contain match characters * and ?.

       RESULT
	  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.

       Most of the fields support a shell style pattern matching. The
       following pattern characters are supported:

       *  Matches zero, or any number of characters.

       ?  Matches any single character.

       [] 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.

       The following keys can get values assigned:

       CTL{numid}, CTL{iface}, CTL{device}, CTL{subdev}, CTL{name},
       CTL{index},
	  Select universal control element.

       CTL{value}
	  Value is set (written) also to soundcard's control device and RESULT
	  key is set to errno code. The result of set operation is always true
	  (it means continue with next key on line).

       CTL{values}
	  Value is set (written) also to soundcard's control device (all
	  control values are set to specified value) and RESULT key is set to
	  errno code. The result of set operation is always true (it means
	  continue with next key on line).

       CTL{write}
	  Value is set (written) also to soundcard's control device (all
	  control values are set to specified value). The result of set
	  operation is true when operation succeed (it means continue with
	  next key on line).

       ENV{key}
	  Export a variable to the environment. Depending on the type of
	  operator, this key is also to match against an environment variable.

       RESULT
	  Set RESULT variable. Note that PROGRAM also sets this variable, but
	  setting this variable manually might be useful to change code
	  execution order (included files).

       LABEL
	  Named label where a GOTO can jump to.

       GOTO
	  Jumps to the next LABEL with a matching name. The goto cannot jump
	  backward.

       INCLUDE
	  Include specified filename or all files in specified directory

       ACCESS
	  Check if specified file or directory exists

       CONFIG{sysfs_device}
	  The relative path to sysfs subsystem specifying the root directory
	  of a soundcard device. Usually, it should be set to
	  "/class/sound/card$cardinfo{card}/device".

       PRINT
	  PRINT value to stdout.

       ERROR
	  PRINT value to stderr.

       EXIT
	  Exit immediately and set program exit code to value (should be
	  integer). If value is "return" string, parser leaves current
	  included file and returns to parent configuration file.

       The PROGRAM, RESULT, CTL{value}, PRINT, ERROR, EXIT, CONFIG{} fields
       support simple printf-like string substitutions. 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:

       $cardinfo{attribute}, %i{attribute}
	  See CARDINFO{} for more details.

       $ctl{attribute}, %C{attribute}
	  See CTL{} for more details.

       $attr{file}, %s{file}
	  The value of a sysfs attribute found at the device, where all keys
	  of the rule have matched. If the attribute is a symlink, the last
	  element of the symlink target is returned as the value.

       $env{key}, %E{key}
	  The value of an environment variable.

       $result, %c
	  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: %c{N}. If
	  the number is followed by the '+' char this part plus all remaining
	  parts of the result string are substituted: %c{N+}

       $sysfsroot, %r
	  Root directory where sysfs file-system is mounted. Ususally, this
	  value is just "/sys".

       $config{key}, %g{key}
	  The value of a configuration variable. See CONFIG{} for more
	  details.

       %% The '%' character itself.

       $$ The '$' character itself.

       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

AUTHOR
       Written by Jaroslav Kysela <perex@perex.cz>

       Some portions are written by Greg Kroah-Hartman <greg@kroah.com> and
       Kay Sievers <kay.sievers@vrfy.org>.

SEE ALSO
       alsactl(1)

alsactl				   July 2008		       ALSACTL_INIT(7)
[top]

List of man pages available for aLinux

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
...................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net