<html lang="en">
<head>
<title>Entering Debug Mode - GNU Octave</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="GNU Octave">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Debugging.html#Debugging" title="Debugging">
<link rel="next" href="Leaving-Debug-Mode.html#Leaving-Debug-Mode" title="Leaving Debug Mode">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<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="Entering-Debug-Mode"></a>
<p>
Next: <a rel="next" accesskey="n" href="Leaving-Debug-Mode.html#Leaving-Debug-Mode">Leaving Debug Mode</a>,
Up: <a rel="up" accesskey="u" href="Debugging.html#Debugging">Debugging</a>
<hr>
</div>
<h3 class="section">13.1 Entering Debug Mode</h3>
<p>There are two basic means of interrupting the execution of an Octave
script. These are breakpoints see <a href="Breakpoints.html#Breakpoints">Breakpoints</a>, discussed in the next
section and interruption based on some condition.
<p>Octave supports three means to stop execution based on the values set in
the functions <code>debug_on_interrupt</code>, <code>debug_on_warning</code> and
<code>debug_on_error</code>.
<!-- debug_on_interrupt src/sighandlers.cc -->
<p><a name="doc_002ddebug_005fon_005finterrupt"></a>
<div class="defun">
— Built-in Function: <var>val</var> = <b>debug_on_interrupt</b> ()<var><a name="index-debug_005fon_005finterrupt-830"></a></var><br>
— Built-in Function: <var>old_val</var> = <b>debug_on_interrupt</b> (<var>new_val</var>)<var><a name="index-debug_005fon_005finterrupt-831"></a></var><br>
— Built-in Function: <b>debug_on_interrupt</b> (<var>new_val, "local"</var>)<var><a name="index-debug_005fon_005finterrupt-832"></a></var><br>
<blockquote><p>Query or set the internal variable that controls whether Octave will try
to enter debugging mode when it receives an interrupt signal (typically
generated with <kbd>C-c</kbd>). If a second interrupt signal is received
before reaching the debugging mode, a normal interrupt will occur.
<p>When called from inside a function with the "local" option, the variable is
changed locally for the function and any subroutines it calls. The original
variable value is restored when exiting the function.
<!-- Texinfo @sp should work but in practice produces ugly results for HTML. -->
<!-- A simple blank line produces the correct behavior. -->
<!-- @sp 1 -->
<p class="noindent"><strong>See also:</strong> <a href="doc_002ddebug_005fon_005ferror.html#doc_002ddebug_005fon_005ferror">debug_on_error</a>, <a href="doc_002ddebug_005fon_005fwarning.html#doc_002ddebug_005fon_005fwarning">debug_on_warning</a>.
</p></blockquote></div>
<!-- debug_on_warning src/error.cc -->
<p><a name="doc_002ddebug_005fon_005fwarning"></a>
<div class="defun">
— Built-in Function: <var>val</var> = <b>debug_on_warning</b> ()<var><a name="index-debug_005fon_005fwarning-833"></a></var><br>
— Built-in Function: <var>old_val</var> = <b>debug_on_warning</b> (<var>new_val</var>)<var><a name="index-debug_005fon_005fwarning-834"></a></var><br>
— Built-in Function: <b>debug_on_warning</b> (<var>new_val, "local"</var>)<var><a name="index-debug_005fon_005fwarning-835"></a></var><br>
<blockquote><p>Query or set the internal variable that controls whether Octave will try
to enter the debugger when a warning is encountered.
<p>When called from inside a function with the "local" option, the variable is
changed locally for the function and any subroutines it calls. The original
variable value is restored when exiting the function.
<!-- Texinfo @sp should work but in practice produces ugly results for HTML. -->
<!-- A simple blank line produces the correct behavior. -->
<!-- @sp 1 -->
<p class="noindent"><strong>See also:</strong> <a href="doc_002ddebug_005fon_005ferror.html#doc_002ddebug_005fon_005ferror">debug_on_error</a>, <a href="doc_002ddebug_005fon_005finterrupt.html#doc_002ddebug_005fon_005finterrupt">debug_on_interrupt</a>.
</p></blockquote></div>
<!-- debug_on_error src/error.cc -->
<p><a name="doc_002ddebug_005fon_005ferror"></a>
<div class="defun">
— Built-in Function: <var>val</var> = <b>debug_on_error</b> ()<var><a name="index-debug_005fon_005ferror-836"></a></var><br>
— Built-in Function: <var>old_val</var> = <b>debug_on_error</b> (<var>new_val</var>)<var><a name="index-debug_005fon_005ferror-837"></a></var><br>
— Built-in Function: <b>debug_on_error</b> (<var>new_val, "local"</var>)<var><a name="index-debug_005fon_005ferror-838"></a></var><br>
<blockquote><p>Query or set the internal variable that controls whether Octave will try
to enter the debugger when an error is encountered. This will also
inhibit printing of the normal traceback message (you will only see
the top-level error message).
<p>When called from inside a function with the "local" option, the variable is
changed locally for the function and any subroutines it calls. The original
variable value is restored when exiting the function.
<!-- Texinfo @sp should work but in practice produces ugly results for HTML. -->
<!-- A simple blank line produces the correct behavior. -->
<!-- @sp 1 -->
<p class="noindent"><strong>See also:</strong> <a href="doc_002ddebug_005fon_005fwarning.html#doc_002ddebug_005fon_005fwarning">debug_on_warning</a>, <a href="doc_002ddebug_005fon_005finterrupt.html#doc_002ddebug_005fon_005finterrupt">debug_on_interrupt</a>.
</p></blockquote></div>
</body></html>
