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:
- TCPIP
-
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.
- -V
- Print version information and exit (ignoring other options).
- -b
- Fork a child to run in the background and exit (daemon mode). Messages are
sent to syslog instead of stderr.
- -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.
- -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.