beep - beep the pc speaker any number of ways
[-f N] [-l N] [-r N] [-d N] [-D N] [-s] [-c]
OPTIONS ] [-n] [--new] [ OPTIONS ]
[-v] [-V] [--version]
allows the user to control the pc-speaker with precision, allowing
different sounds to indicate different events. While it can be run quite
happily on the command line, it's intended place of residence is within
shell/perl scripts, notifying the user when something interesting occurs. Of
course, it has no notion of what's interesting, but it's real good at that
All options have default values, meaning that just typing ' beep
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
- -f N
- beep at N Hz, where 0 < N < 20000. As a general
ballpark, the regular terminal beep is around 750Hz. N is not,
incidentally, restricted to whole numbers.
- -l N
- beep for N milliseconds.
- -r N
- specify the number of repetitions (defaults to 1).
- -d N, -D N
- specify a delay of N milliseconds between repetitions. Use
of -d specifies that this delay should only occur between beeps,
that is, it should not occur after the last repetition. -D indicates that
the delay should occur after every repetition, including the last.
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
- this option allows you to break the command line up into
specifying multiple beeps. Each time this option is used, beep starts
treating all further arguments as though they were for a new beep. So for
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 -n
allows you to specify different beeps. After a -n, the new beep is created
with all the default values, and any of these can be specified without
altering values for preceeding (or later) beeps. See the EXAMPLES
section if this managed to confuse you.
- -s, -c
- these options put beep into input-processing mode.
-s tells beep to read from stdin, and beep after each newline, and
-c tells it to do so after every character. In both cases, the program
will also echo the input back out to stdout, which makes it easy to slip
beep into a text-processing pipeline, see the EXAMPLES
- -h, --help
- display usage info and exit
- -v, -V, --version
- display version information and exit
- At its simplest (yet still effective)
- 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 don't 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).
Some users will encounter a situation where beep dies with a complaint from
ioctl(). The reason for this, as Peter Tirsek was nice enough to point out to
me, stems from how the kernel handles beep's attempt to poke at (for
non-programmers: ioctl is a sort of catch-all function that lets you poke at
things that have no other predefined poking-at mechanism) the tty, which is
how it beeps. The short story is, the kernel checks that either:
- you are the superuser
- you own the current tty
What this means is that root can always make beep work (to the best of my
knowledge!), and that any local user can make beep work, BUT a non-root remote
user cannot use beep in it's natural state. What's worse, an xterm, or other
x-session counts, as far as the kernel is concerned, as 'remote', so beep
won't work from a non-priviledged xterm either. I had originally chalked this
up to a bug, but there's actually nothing I can do about it, and it really is
a Good Thing that the kernel does things this way. There is also a solution.
By default beep is not installed with the suid bit set, because that would just
be zany. On the other hand, if you do make it suid root, all your problems
with beep bailing on ioctl calls will magically vanish, which is pleasant, and
the only reason not to is that any suid program is a potential security hole.
Conveniently, beep is very short, so auditing it is pretty straightforward.
Decide for yourself, of course, but it looks safe to me - there's only one
buffer and fgets doesn't let it overflow, there's only one file opening, and
while there is a potential race condition there, it's with /dev/console. If
someone can exploit this race by replacing /dev/console, you've got bigger
So the quick, only, and likely safe solution if beep is not beeping when you
want it to is (as root):
# chmod 4755 /usr/bin/beep
(or wherever you put it)
The one snag is that this will give any little nitwit the ability to run beep
successfully - make sure this is what you want. If it isn't, a slightly more
complex fix would be something like:
# chgrp beep /usr/bin/beep
# chmod 4750 /usr/bin/beep
and then add only beep-worthy users to the 'beep' group.
Several people have asked for some basic help translating music notes to
frequencies. There are a lot of music notes, and several tables online will
give you translations, but here are approximate
numbers for the octave
of middle C, to get you started.
None that I'm aware of, though see the IOCTL WACKINESS
Report bugs to <email@example.com>
This program was written by Johnathan Nightingale (firstname.lastname@example.org) and is
distributed under the GNU General Public License. For more contributing
information, check the source, and past contributors can be found in CREDITS.