audiorecord - record an audio file
audiorecord [-af] [-v vol] [-c channels] [-s rate]
[-e encoding] [-t time] [-i info] [-d dev]
[-T au|aif[f]|wav] [file[.au|.aif[f]|.wav]]
The audiorecord utility copies audio data from the audio device to a
named audio file, or to the standard output if no filename is present. If no
output file is specified and standard output is a tty, the program exits with
an error message.
By default, monaural audio data is recorded at 8 kHz and encoded
in u-law format. If the audio device supports additional
configurations, the -c, -s, and -e options may be used
to specify the data format. The output file is prefixed by an audio file
header that identifies the format of the data encoded in the file.
Recording begins immediately and continues until a SIGINT
signal (for example, Control-c) is received. If the -t option is
specified, audiorecord stops when the specified quantity of data has
If the audio device is unavailable, that is, if another process
currently has read access, audiorecord prints an error message and
The following options are supported:
Help: Prints a command line usage message.
Append: Appends the data on the end of the named
audio file. The audio device must support the audio data format of the
Channels: Specifies the number of audio channels
(1 or 2). The value may be specified as an integer or as the string
mono or stereo. The default value is mono.
Device: The dev argument specifies an
alternate audio device from which input should be taken. If the -d
option is not specified, the AUDIODEV environment variable is consulted
(see below). Otherwise, /dev/audio is used as the default audio
Encoding: Specifies the audio data encoding. This
value may be one of ulaw, alaw, or linear. The default
encoding is ulaw.
Force: When the -a flag is specified, the
sample rate of the audio device must match the sample rate at which the
original file was recorded. If the -f flag is also specified, sample
rate differences are ignored, with a warning message printed on the standard
Information: The `information' field of the output
file header is set to the string specified by the info argument. This
option cannot be specified in conjunction with the -a argument.
Sample Rate: Specifies the sample rate, in samples
per second. If a number is followed by the letter k, it is multiplied
by 1000 (for example, 44.1k = 44100). The default sample rate is 8 kHz.
Time: The time argument specifies the
maximum length of time to record. Time can be specified as a floating-point
value, indicating the number of seconds, or in the form: hh:mm:ss.dd,
where the hour and minute specifications are optional.
-T au | aif[f] | wav
Specifies the audio file type to create. If the -a
option is used, the file type must match the file to which it is being
appended. Regardless of the file suffix, the type is set as specified in this
option. If this option is not specified, the file suffix determines the
Volume: The recording gain is set to the specified
value before recording begins, and is reset to its previous level when
audiorecord exits. The vol argument is an integer value between
0 and 100, inclusive. If this argument is not specified, the input volume
remains at the level most recently set by any process.
See largefile(5) for the description of the behavior of
audiorecord when encountering files greater than or equal to 2 Gbyte
: The named audio file is
rewritten, or appended. If no filename is present, and standard output is not
a tty, or if the special filename "−
" is specified,
output is directed to the standard output.
If the -T option is not specified, the file suffix
determines the type of file. If the suffix is not recognized, the default is
.au. If the -T option is specified, that file type is
used regardless of the file suffix.
The full path name of the audio device to record from, if
no -d argument is supplied. If the AUDIODEV variable is not set,
/dev/audio is used.
audioconvert(1), audioplay(1), largefile(5),