NAME
nasd - Network Audio System server
SYNOPSIS
nasd [:listen port offset] [-option ...]
DESCRIPTION
nasd is the generic name for the Network
Audio System server. It is frequently a link or a copy of the
appropriate server binary for driving the most frequently used
server on a given machine.
STARTING THE SERVER
The server is usually started from
/etc/rc or a user's startup script.
When the Network Audio System server starts up, it takes over
/dev/audio. Note, that if ReleaseDevice is set to TRUE [default] in
the nasd.conf file, nasd will relinquish control of the audio
device whenever it has finished playing a sound. This means you can
use other non-NAS applications when nasd is running, as long as
nasd isn't currently playing a song. If ReleaseDevice is set to
FALSE in the nasd.conf file, applications that attempt to access
/dev/audio themselves will fail while nasd is running.
NETWORK CONNECTIONS
The Network Audio System server
supports connections made using the following reliable
byte-streams:
- TCP/IP
-
The server listens on port 8000+n, where n is the
listen port offset.
- Unix Domain
- The X server uses /tmp/.sockets/audion as the
filename for the socket, where n is the display
number.
OPTIONS
All of the Network Audio System servers accept the
following generic command line options. Options specific to a
particular server may also be available, and are not listed here.
Try 'nasd -?' for a list of those options, if available.
- -aa
- Allows any client to connect. By default, access is allowed
only to authenticated clients.
- -local
- Allows only clients on the local host to connect. By default,
access is allowed to local and remote hosts.
- -v
- Enable verbose messages. This option overrides the nasd.conf
file setting.
- -b
- Fork a child to run in the background and exit (daemon mode).
- -d n
- Enable debugging output at level n, where n is a
positive integer. The higher the level, the more output you will
get. A value of 0 [default] disables debugging output. This option
overrides the nasd.conf file setting. When debugging is enabled,
stderr is not closed by the nasd process, and all debugging
messages are written there.
- -pn
- -nopn [default]
- Enables or disables Partial Networking. Enabling Partial
Networking allows the server to start, even if the server cannot
establish all of its well-known sockets (connection points for
clients), but establishes at least one.
- -config file
- Use the config file file, instead of the default
(/etc/nasd/nasd.conf).
SIGNALS
The Network Audio System server attaches special
meaning to the following signals:
- SIGHUP
- This signal causes the server to close all existing
connections, free all resources, and restore all defaults.
- SIGTERM
- This signal causes the server to exit cleanly.
- SIGUSR1
- This signal is used quite differently from either of the above.
When the server starts, it checks to see if it has inherited
SIGUSR1 as SIG_IGN instead of the usual SIG_DFL. In this case, the
server sends a SIGUSR1 to its parent process after it has set up
the various connection schemes.
DIAGNOSTICS
Too numerous to list them all.
FILES
- /tmp/.sockets/audio*
- Unix domain socket
- /usr/adm/audio*msgs
- /dev/audio
- Audio device
SEE ALSO
nas(1), auinfo(1),
auplay(1),
auctl(1),
nasd.conf(1)
BUGS
If au dies before its clients, new clients won't be able
to connect until all existing connections have their TCP TIME_WAIT
timers expire.
The current access control support is weak at best.
COPYRIGHT
Copyright 1993, Network Computing Devices,
Inc.
AUTHORS
The Network Audio System server was originally
written by Greg Renda and Dave Lemke, with large amounts of code
borrowed from the sample X server.
The sample X server was originally written by Susan Angebranndt,
Raymond Drewry, Philip Karlton, and Todd Newman, from Digital
Equipment Corporation, with support from a large cast. It has since
been extensively rewritten by Keith Packard and Bob Scheifler, from
MIT.