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17<title>Debugging with GDB: Introduction and Notation</title>
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64<a name="Introduction-and-Notation"></a>
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66<p>
67Next: <a href="Readline-Interaction.html#Readline-Interaction" accesskey="n" rel="next">Readline Interaction</a>, Up: <a href="Command-Line-Editing.html#Command-Line-Editing" accesskey="u" rel="up">Command Line Editing</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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70<a name="Introduction-to-Line-Editing"></a>
71<h3 class="section">32.1 Introduction to Line Editing</h3>
72
73<p>The following paragraphs describe the notation used to represent
74keystrokes.
75</p>
76<p>The text <kbd>C-k</kbd> is read as &lsquo;Control-K&rsquo; and describes the character
77produced when the <tt class="key">k</tt> key is pressed while the Control key
78is depressed.
79</p>
80<p>The text <kbd>M-k</kbd> is read as &lsquo;Meta-K&rsquo; and describes the character
81produced when the Meta key (if you have one) is depressed, and the <tt class="key">k</tt>
82key is pressed.
83The Meta key is labeled <tt class="key">ALT</tt> on many keyboards.
84On keyboards with two keys labeled <tt class="key">ALT</tt> (usually to either side of
85the space bar), the <tt class="key">ALT</tt> on the left side is generally set to
86work as a Meta key.
87The <tt class="key">ALT</tt> key on the right may also be configured to work as a
88Meta key or may be configured as some other modifier, such as a
89Compose key for typing accented characters.
90</p>
91<p>If you do not have a Meta or <tt class="key">ALT</tt> key, or another key working as
92a Meta key, the identical keystroke can be generated by typing <tt class="key">ESC</tt>
93<em>first</em>, and then typing <tt class="key">k</tt>.
94Either process is known as <em>metafying</em> the <tt class="key">k</tt> key.
95</p>
96<p>The text <kbd>M-C-k</kbd> is read as &lsquo;Meta-Control-k&rsquo; and describes the
97character produced by <em>metafying</em> <kbd>C-k</kbd>.
98</p>
99<p>In addition, several keys have their own names.  Specifically,
100<tt class="key">DEL</tt>, <tt class="key">ESC</tt>, <tt class="key">LFD</tt>, <tt class="key">SPC</tt>, <tt class="key">RET</tt>, and <tt class="key">TAB</tt> all
101stand for themselves when seen in this text, or in an init file
102(see <a href="Readline-Init-File.html#Readline-Init-File">Readline Init File</a>).
103If your keyboard lacks a <tt class="key">LFD</tt> key, typing <tt class="key">C-j</tt> will
104produce the desired character.
105The <tt class="key">RET</tt> key may be labeled <tt class="key">Return</tt> or <tt class="key">Enter</tt> on
106some keyboards.
107</p>
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110<p>
111Next: <a href="Readline-Interaction.html#Readline-Interaction" accesskey="n" rel="next">Readline Interaction</a>, Up: <a href="Command-Line-Editing.html#Command-Line-Editing" accesskey="u" rel="up">Command Line Editing</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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