110 lines
5.6 KiB
HTML
110 lines
5.6 KiB
HTML
<html lang="en">
|
|
<head>
|
|
<title>Signaling - Debugging with GDB</title>
|
|
<meta http-equiv="Content-Type" content="text/html">
|
|
<meta name="description" content="Debugging with GDB">
|
|
<meta name="generator" content="makeinfo 4.13">
|
|
<link title="Top" rel="start" href="index.html#Top">
|
|
<link rel="up" href="Altering.html#Altering" title="Altering">
|
|
<link rel="prev" href="Jumping.html#Jumping" title="Jumping">
|
|
<link rel="next" href="Returning.html#Returning" title="Returning">
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
|
<!--
|
|
Copyright (C) 1988-2019 Free Software Foundation, Inc.
|
|
|
|
Permission is granted to copy, distribute and/or modify this document
|
|
under the terms of the GNU Free Documentation License, Version 1.3 or
|
|
any later version published by the Free Software Foundation; with the
|
|
Invariant Sections being ``Free Software'' and ``Free Software Needs
|
|
Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,''
|
|
and with the Back-Cover Texts as in (a) below.
|
|
|
|
(a) The FSF's Back-Cover Text is: ``You are free to copy and modify
|
|
this GNU Manual. Buying copies from GNU Press supports the FSF in
|
|
developing GNU and promoting software freedom.''
|
|
-->
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
|
<style type="text/css"><!--
|
|
pre.display { font-family:inherit }
|
|
pre.format { font-family:inherit }
|
|
pre.smalldisplay { font-family:inherit; font-size:smaller }
|
|
pre.smallformat { font-family:inherit; font-size:smaller }
|
|
pre.smallexample { font-size:smaller }
|
|
pre.smalllisp { font-size:smaller }
|
|
span.sc { font-variant:small-caps }
|
|
span.roman { font-family:serif; font-weight:normal; }
|
|
span.sansserif { font-family:sans-serif; font-weight:normal; }
|
|
--></style>
|
|
</head>
|
|
<body>
|
|
<div class="node">
|
|
<a name="Signaling"></a>
|
|
<p>
|
|
Next: <a rel="next" accesskey="n" href="Returning.html#Returning">Returning</a>,
|
|
Previous: <a rel="previous" accesskey="p" href="Jumping.html#Jumping">Jumping</a>,
|
|
Up: <a rel="up" accesskey="u" href="Altering.html#Altering">Altering</a>
|
|
<hr>
|
|
</div>
|
|
|
|
<h3 class="section">17.3 Giving your Program a Signal</h3>
|
|
|
|
<p><a name="index-deliver-a-signal-to-a-program-1170"></a>
|
|
|
|
<a name="index-signal-1171"></a>
|
|
<dl><dt><code>signal </code><var>signal</var><dd>Resume execution where your program is stopped, but immediately give it the
|
|
signal <var>signal</var>. The <var>signal</var> can be the name or the number of a
|
|
signal. For example, on many systems <code>signal 2</code> and <code>signal
|
|
SIGINT</code> are both ways of sending an interrupt signal.
|
|
|
|
<p>Alternatively, if <var>signal</var> is zero, continue execution without
|
|
giving a signal. This is useful when your program stopped on account of
|
|
a signal and would ordinarily see the signal when resumed with the
|
|
<code>continue</code> command; ‘<samp><span class="samp">signal 0</span></samp>’ causes it to resume without a
|
|
signal.
|
|
|
|
<p><em>Note:</em> When resuming a multi-threaded program, <var>signal</var> is
|
|
delivered to the currently selected thread, not the thread that last
|
|
reported a stop. This includes the situation where a thread was
|
|
stopped due to a signal. So if you want to continue execution
|
|
suppressing the signal that stopped a thread, you should select that
|
|
same thread before issuing the ‘<samp><span class="samp">signal 0</span></samp>’ command. If you issue
|
|
the ‘<samp><span class="samp">signal 0</span></samp>’ command with another thread as the selected one,
|
|
<span class="sc">gdb</span> detects that and asks for confirmation.
|
|
|
|
<p>Invoking the <code>signal</code> command is not the same as invoking the
|
|
<code>kill</code> utility from the shell. Sending a signal with <code>kill</code>
|
|
causes <span class="sc">gdb</span> to decide what to do with the signal depending on
|
|
the signal handling tables (see <a href="Signals.html#Signals">Signals</a>). The <code>signal</code> command
|
|
passes the signal directly to your program.
|
|
|
|
<p><code>signal</code> does not repeat when you press <RET> a second time
|
|
after executing the command.
|
|
|
|
<p><a name="index-queue_002dsignal-1172"></a><br><dt><code>queue-signal </code><var>signal</var><dd>Queue <var>signal</var> to be delivered immediately to the current thread
|
|
when execution of the thread resumes. The <var>signal</var> can be the name or
|
|
the number of a signal. For example, on many systems <code>signal 2</code> and
|
|
<code>signal SIGINT</code> are both ways of sending an interrupt signal.
|
|
The handling of the signal must be set to pass the signal to the program,
|
|
otherwise <span class="sc">gdb</span> will report an error.
|
|
You can control the handling of signals from <span class="sc">gdb</span> with the
|
|
<code>handle</code> command (see <a href="Signals.html#Signals">Signals</a>).
|
|
|
|
<p>Alternatively, if <var>signal</var> is zero, any currently queued signal
|
|
for the current thread is discarded and when execution resumes no signal
|
|
will be delivered. This is useful when your program stopped on account
|
|
of a signal and would ordinarily see the signal when resumed with the
|
|
<code>continue</code> command.
|
|
|
|
<p>This command differs from the <code>signal</code> command in that the signal
|
|
is just queued, execution is not resumed. And <code>queue-signal</code> cannot
|
|
be used to pass a signal whose handling state has been set to <code>nopass</code>
|
|
(see <a href="Signals.html#Signals">Signals</a>).
|
|
</dl>
|
|
<!-- @end group -->
|
|
|
|
<p>See <a href="stepping-into-signal-handlers.html#stepping-into-signal-handlers">stepping into signal handlers</a>, for information on how stepping
|
|
commands behave when the thread has a signal queued.
|
|
|
|
</body></html>
|
|
|