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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 applications that attempt to access /dev/audio themselves will fail while it 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 command line options:
-aa
Allows clients on any host to connect. By default, access is allowed only to clients on the local host.

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.


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