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<h5 class="subsubsection">17.4.9.2 Characters that Cause Signals</h5>

<p>These special characters may be active in either canonical or noncanonical
input mode, but only when the <code>ISIG</code> flag is set (see <a href="Local-Modes.html#Local-Modes">Local Modes</a>).

<!-- termios.h -->
<!-- POSIX.1 -->
<div class="defun">
&mdash; Macro: int <b>VINTR</b><var><a name="index-VINTR-1971"></a></var><br>
<blockquote><p><a name="index-INTR-character-1972"></a><a name="index-interrupt-character-1973"></a>This is the subscript for the INTR character in the special control
character array.  <var>termios</var><code>.c_cc[VINTR]</code> holds the character
itself.

        <p>The INTR (interrupt) character raises a <code>SIGINT</code> signal for all
processes in the foreground job associated with the terminal.  The INTR
character itself is then discarded.  See <a href="Signal-Handling.html#Signal-Handling">Signal Handling</a>, for more
information about signals.

        <p>Typically, the INTR character is <kbd>C-c</kbd>. 
</p></blockquote></div>

<!-- termios.h -->
<!-- POSIX.1 -->
<div class="defun">
&mdash; Macro: int <b>VQUIT</b><var><a name="index-VQUIT-1974"></a></var><br>
<blockquote><p><a name="index-QUIT-character-1975"></a>This is the subscript for the QUIT character in the special control
character array.  <var>termios</var><code>.c_cc[VQUIT]</code> holds the character
itself.

        <p>The QUIT character raises a <code>SIGQUIT</code> signal for all processes in
the foreground job associated with the terminal.  The QUIT character
itself is then discarded.  See <a href="Signal-Handling.html#Signal-Handling">Signal Handling</a>, for more information
about signals.

        <p>Typically, the QUIT character is <kbd>C-\</kbd>. 
</p></blockquote></div>

<!-- termios.h -->
<!-- POSIX.1 -->
<div class="defun">
&mdash; Macro: int <b>VSUSP</b><var><a name="index-VSUSP-1976"></a></var><br>
<blockquote><p><a name="index-SUSP-character-1977"></a><a name="index-suspend-character-1978"></a>This is the subscript for the SUSP character in the special control
character array.  <var>termios</var><code>.c_cc[VSUSP]</code> holds the character
itself.

        <p>The SUSP (suspend) character is recognized only if the implementation
supports job control (see <a href="Job-Control.html#Job-Control">Job Control</a>).  It causes a <code>SIGTSTP</code>
signal to be sent to all processes in the foreground job associated with
the terminal.  The SUSP character itself is then discarded. 
See <a href="Signal-Handling.html#Signal-Handling">Signal Handling</a>, for more information about signals.

        <p>Typically, the SUSP character is <kbd>C-z</kbd>. 
</p></blockquote></div>

   <p>Few applications disable the normal interpretation of the SUSP
character.  If your program does this, it should provide some other
mechanism for the user to stop the job.  When the user invokes this
mechanism, the program should send a <code>SIGTSTP</code> signal to the
process group of the process, not just to the process itself. 
See <a href="Signaling-Another-Process.html#Signaling-Another-Process">Signaling Another Process</a>.

<!-- termios.h -->
<!-- BSD -->
<div class="defun">
&mdash; Macro: int <b>VDSUSP</b><var><a name="index-VDSUSP-1979"></a></var><br>
<blockquote><p><a name="index-DSUSP-character-1980"></a><a name="index-delayed-suspend-character-1981"></a>This is the subscript for the DSUSP character in the special control
character array.  <var>termios</var><code>.c_cc[VDSUSP]</code> holds the character
itself.

        <p>The DSUSP (suspend) character is recognized only if the implementation
supports job control (see <a href="Job-Control.html#Job-Control">Job Control</a>).  It sends a <code>SIGTSTP</code>
signal, like the SUSP character, but not right away&mdash;only when the
program tries to read it as input.  Not all systems with job control
support DSUSP; only BSD-compatible systems (including the GNU system).

        <p>See <a href="Signal-Handling.html#Signal-Handling">Signal Handling</a>, for more information about signals.

        <p>Typically, the DSUSP character is <kbd>C-y</kbd>. 
</p></blockquote></div>

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