Bell character

<h2 id="representations">Representations</h2>
<p>In <a href="/facts/ASCII/vGUI33Qu">ASCII</a> the bell character's value is 7 and is named "BELL" or "BEL". <a href="/facts/Unicode/DDu3MfPV">Unicode</a> does not give names to control characters but has assigned it the alias "ALERT" and abbreviation "BEL." It can sometimes be typed as ctrl+G and displayed as ^G in <a href="/facts/Caret_notation/IHAVdW9R">caret notation</a>. Unicode also includes characters for the visual representation of the character: U+2407 ␇ SYMBOL FOR BELL and U+237E ⍾ BELL SYMBOL.
</p><p>In the 5-bit Baudot codes, BEL is represented by the number 11 (0x0B) when in "figures" mode.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> The code 0x2F is used in <a href="/facts/EBCDIC/qAhmvgj0">EBCDIC</a>.
</p><p>In the programming language <a href="/facts/C_(programming_language)/Ky2No763">C</a> (created in 1972), and in many languages influenced by it such as <a href="/facts/Python_(programming_language)/YbuGqofa">Python</a>, the bell character can be placed in a string or character constant with \a. 'a' stands for "alert" or "audible" and was chosen because \b was already used for the <a href="/facts/Backspace/ySuesUGR">backspace</a> character.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
</p>
<h2 id="usage">Usage</h2>

<p>On <a href="/facts/Unix-like/YAKrAxzd">Unix-like</a> systems, or on <a href="/facts/MS-DOS/fVrrz1uN">MS-DOS</a> or <a href="/facts/Microsoft_Windows/bwhAhuSL">Windows</a>, a user can cause the equivalent of ringing the bell to happen by typing at the <a href="/facts/Command_line_interpreter/R9JpGmXQ">command prompt</a> the command:
</p>
echo ^G

<p>where the ^G is produced by holding down Ctrl and typing G. On Unix the user may need to type Ctrl+V first to "quote" the ^G.
</p><p>On POSIX systems, one may also use:
</p>
printf '\a'

<p>and in the <a href="/facts/Bash_(Unix_shell)/RrYLtEJT">Bash</a> shell, one may use ANSI-C quoting:<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a>
</p>
echo $'\a'

<p>An alternative is to use the <a href="/facts/Tput/ts7xW2Iy">tput</a> command, which as a part of the <a href="/facts/Ncurses/anPTppfj">ncurses</a> library is available on most Unix/Linux operating systems:
</p>
tput bel

<p>A program can get the same result by printing the BEL character to a terminal.
</p><p>On modern systems this may not make a noise; it may instead make a visual indication such as flashing the screen, or do nothing at all.
</p>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/C0_and_C1_control_codes/bBp1dGVl">C0 and C1 control codes</a> (<a href="/facts/ISO_646/7CdXUnTs">ISO 646</a>)</li></ul>

<ul><li><a href="https://web.archive.org/web/20160303230740/http://www.atis.org/glossary/definition.aspx?id=5756">ATIS Telcom Glossary</a></li>
<li><a href="http://foldoc.org/bell">Free On-Line Dictionary of Computing, 'bell'</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>"Baudot". Archived from the original on December 19, 2008. Retrieved February 1, 2009. <a href="https://web.archive.org/web/20081219135647/http://chem.ch.huji.ac.il/history/baudot.html" target="_blank">https://web.archive.org/web/20081219135647/http://chem.ch.huji.ac.il/history/baudot.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Smith, Gil (2001). "Teletype Communication Codes" (PDF). Baudot.net. Archived (PDF) from the original on 20 August 2008. Retrieved 2008-07-11. <a href="http://www.baudot.net/docs/smith--teletype-codes.pdf" target="_blank">http://www.baudot.net/docs/smith--teletype-codes.pdf</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>"The Lorenz Cipher and how Bletchley Park broke it". www.codesandciphers.org.uk. Retrieved 9 July 2016. <a href="http://www.codesandciphers.org.uk/lorenz/fish.htm" target="_blank">http://www.codesandciphers.org.uk/lorenz/fish.htm</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>"2. Lexical analysis — Python 2.7.18 documentation". docs.python.org. Retrieved 2021-02-05. <a href="https://docs.python.org/2/reference/lexical_analysis.html#grammar-token-stringliteral" target="_blank">https://docs.python.org/2/reference/lexical_analysis.html#grammar-token-stringliteral</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>ANSI-C quoting <a href="https://www.gnu.org/software/bash/manual/bash.html#ANSI_002dC-Quoting" target="_blank">https://www.gnu.org/software/bash/manual/bash.html#ANSI_002dC-Quoting</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
</ol>

Bell character open-in-new

Bell character