beep man page

beep — beep the pc speaker any number of ways

Examples (TL;DR)

Synopsis

beep [GLOBALS] [-f FREQ] [-l LEN] [-r REPEATS] [<-d|-D> DELAY] [-s] [-c]
beep [GLOBALS] <TONE_OPTIONS> [-n|--new] <TONE_OPTIONS>
beep <-h|--help>
beep <-v|-V|--version>

Description

beep allows the user to control the PC speaker with precision, allowing different sounds to indicate different events.  While beep can be run quite happily on the command line, beep's intended use is within shell/perl scripts, notifying the user when something interesting occurs.  Of course, it has no notion of what IS interesting, but it is good at the notifying part.

All options have default values, meaning that just typing 'beep' will work.  If an option is specified more than once on the command line, subsequent options override their predecessors.  So 'beep -f 200 -f 300' will beep at 300Hz.

All durations are given in a unit of milliseconds, frequencies as Hertz, and the number of repeats is a dimensionless number.

Options

Global options

-e DEVICE--device=DEVICE

Explicitly set the device beep shall use to generate beep tones.  When not given a device explicitly, beep runs through an internal list of devices until one appears to work.

--debug--verbose

Make the beep program more verbose.

Tone options

-f FREQ

Beep with a tone frequency of FREQ Hz, where 0 < FREQ < 20000.  As a general ballpark, the regular terminal beep is around 750Hz.  For backwards compatibility, you can give FREQ as a floating point number, but beep will round that to integer values as the kernel APIs expect them.

-l LEN

Beep for a tone length of LEN milliseconds.

-r REPEATS

Repeat the tone including delays REPEATS times (defaults to 1).

-d DELAY | -D DELAY

Specify a delay of DELAY milliseconds between repetitions.  Small letter -d specifies that this delay should only occur between beeps, that is, it should not occur after the last repetition.  Capital letter -D specifies that the delay should occur after every repetition, including the last one.  Normally, -d is what you want, but if, for example, you are stringing several beep commands together to play the star wars anthem, you may want control over every delay.

-n--new

The --new option allows you to chain multiple beeps together on a single command line.  Each time the --new is used, beep starts treating all further arguments as though they were for a new beep.  So for example:

   beep -f 1000 -n -f 2000 -n -f 1500

would produce a sequence of three beeps, the first with a frequency of 1000Hz (and otherwise default values), then a second beep with a frequency of 2000Hz (again, with things like delay and reps being set to their defaults), then a third beep, at 1500Hz.  This is different from specifying a -r value, since -r repeats the same beep multiple times, whereas --new allows you to specify different beeps.  After a --new, the new beep is created with all the default values, and any of these can be specified without altering values for preceding (or later) beeps.  See the Examples section if this managed to confuse you.

-s-c

Both the -s and the -c option put beep into input processing mode.  -s tells beep to read from stdin, and beep after each newline.  -c tells beep to beep after every character.  In both cases, the beep will also echo the input back out to stdout, which makes it easy to slip beep into a text processing pipeline.  See the Examples section.

Other Actions

-h--help Display beep usage info and exit.

-v-V--version

Display beep version information and exit.

Exit Status

When successful, beep returns with exit code 0.

Any non-0 exit means beep has encountered an error and has bailed out.

Files

The device files beep uses by default are the following:
   /dev/input/by-path/platform-pcspkr-event-spkr
   /dev/tty0
   /dev/vc/0

Notes

Devices and Permissions

When you run beep without explicitly giving a device to use, beep tries opening the following devices in sequence until one succeeds:

/dev/input/by-path/platform-pcspkr-event-spkr

Uses the evdev API, and system administrator can allow access to any set of users and groups using the normal file permissions.

/dev/tty0

Uses the console API, and the kernel insists you are root or own the TTY.

/dev/vc/0

Uses the console API, and the kernel insists you are root or own the TTY.

beep does not support running as setuid root or via sudo(1).

For non-root uses, the system administrator can set up a udev(7) rule to allow write access to /dev/input/by-path/platform-pcspkr-event-spkr for certain users and/or user groups. For details, see the beep /usr/share/doc/beep/PERMISSIONS.md file.

APIs

evdev

Uses the input event device driver, which means running write(2) on /dev/input/by-path/platform-pcspkr-event-spkr.

console

Uses the ancient console API, which means running the KIOCSOUND ioctl(2) on a tty device like /dev/tty0 or /dev/vc/0.

Concurrent Invocations

Concurrent invocations of beep are not supported. There is only one tone generator in the PC hardware, and we do not manage access to that shared resource in any way.  So if a first beep -f 1000 -l 10000 process starts a long 10 second beep with 1000Hz, and 2 seconds later a second quick beep -f 2050 -l 100 with 2050Hz comes in, you will hear that 2050Hz beep for 100ms, and then silence as the quick beep silences the tone generator. Now you will not hear that the first beep process is still running after having waited for the first 2100ms of 10000ms. You will also not that the first beep process will silence the already silent speaker 7900ms later, i.e. 10000ms after the first beep started.

Sound Volume

The PC speaker hardware has no way to explicitly set the volume of a beep.

If you have a standalone PC, however, chances are you have a piezo beeper connected to the mainboard.  If you prioritize a loud beep over a certain frequency beep, you can choose to beep at a frequency close to the resonance frequency of the piezo beeper.  Typical piezo beepers have a resonance frequency around 2000Hz, so you can test frequencies around that range.  The author's piezo beeper is the loudest at about 2050Hz.

If you have a PC laptop, chances are that your laptop will not have a piezo beeper hardware inside and that it will route the output of the pcspkr circuit to the laptop's internal speakers via the sound card mixer.  In that case, you can and/or must change the mixer level for the beeper using a sound card mixer application.

Frequency Table

This frequency table might come in hand for translating musical notes to frequencies.  The frequencies are rounded to integer numbers as the kernel driver only works with integers.  The column for octave 4 is the octave of middle C.

note octave
name 3 4 5 6
C 131 262 523 1047
C# 139 277 554 1109
D 147 294 587 1175
D# 156 311 622 1245
E 165 330 659 1319
F 175 349 698 1397
F# 185 370 740 1480
G 196 392 784 1568
G# 208 415 831 1661
A 220 440 880 1760
A# 233 466 932 1865
B 247 494 988 1976
C 262 523 1047 2093

Bugs

Report bugs to https://github.com/spkr-beep/beep/issues.

Examples

At its simplest (yet still effective)

   beep

A more interesting standalone setup

   beep -f 300.7 -r 2 -d 100 -l 400

As part of a log watching pipeline

   tail -f /var/log/xferlog | grep 'passwd' | beep -f 1000 -r 5 -s

When using -c mode, I recommend using a short -D, and a shorter -l, so that the beeps do not blur together.  Something like this will get you a cheesy 1970's style beep-as-you-type-each-letter effect

   cat file | beep -c -f 400 -D 50 -l 10

A highly contrived example of -n/--new usage

   beep -f 1000 -r 2 -n -r 5 -l 10 --new

will produce first two 1000Hz beeps, then 5 beeps at the default tone, but only 10ms long each, followed by a third beep using all the default settings (since none are specified).

See Also

/usr/share/doc/beep/README.fedora, /usr/share/doc/beep/README.md, /usr/share/doc/beep/PERMISSIONS.md, https://github.com/spkr-beep/beep

Info

2019-01-11 Linux User commands