Bell character
From Wikipedia, the free encyclopedia
Bell character is an ASCII control character, code 7 (^G). When it is sent to a printer or a terminal, nothing is printed, but an audible signal is emitted instead. Terminal emulators usually offer visual bell which flashes the terminal window briefly to show the user where the alert occurred.
A bell code also exists in Baudot code, which has been used in teleprinters in some form since 1874. Sending a bell code would get the attention of the teleprinter operator at the other end of the line.
In the C programming language, the bell character is represented as '\a' ("alert" or "audible"). In Unicode, there is a character for visual representation of bell character, ”symbol for bell“, U+2407 (␇) — not to be confused with the actual bell character, U+0007.
In the Windows Command prompt, as with the earlier PC-DOS or MS-DOS command prompts on which it is based, and in the command prompt on Unix-like systems, the user can type the word "echo" followed by a CTRL+G, which will appear as
echo ^G
and when the user presses enter, the computer will emit a beep sound.
[edit] Disabling the beep
Some people find machine beeps and other sounds annoying and want to remove them. On a Windows machine this can be accomplished by taking one of the following steps:
- Download Powertoys. It has a setting for disabling the beep
- In Device Manager, select "Show Hidden Devices", then disable "Beep" under "Non-Plug and Play Drivers"
- In Command Prompt type "NET STOP beep"
On a Linux machine this can be accomplished by taking one of the following steps:
- Add a line "blacklist pcspkr" in the /etc/modprobe.d/blacklist file
- Type "xset b off" in a terminal, or in the Xsession file
