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<title>Using as: Strings</title>

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<a name="Strings"></a>
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<p>
Next: <a href="Chars.html#Chars" accesskey="n" rel="next">Chars</a>, Up: <a href="Characters.html#Characters" accesskey="u" rel="up">Characters</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Strings-1"></a>
<h4 class="subsubsection">3.6.1.1 Strings</h4>

<a name="index-string-constants"></a>
<a name="index-constants_002c-string"></a>
<p>A <em>string</em> is written between double-quotes.  It may contain
double-quotes or null characters.  The way to get special characters
into a string is to <em>escape</em> these characters: precede them with
a backslash &lsquo;<samp>\</samp>&rsquo; character.  For example &lsquo;<samp>\\</samp>&rsquo; represents
one backslash:  the first <code>\</code> is an escape which tells
<code>as</code> to interpret the second character literally as a backslash
(which prevents <code>as</code> from recognizing the second <code>\</code> as an
escape character).  The complete list of escapes follows.
</p>
<a name="index-escape-codes_002c-character"></a>
<a name="index-character-escape-codes"></a>
<dl compact="compact">
<dd><a name="index--_005cb-_0028backspace-character_0029"></a>
<a name="index-backspace-_0028_005cb_0029"></a>
</dd>
<dt><kbd>\b</kbd></dt>
<dd><p>Mnemonic for backspace; for ASCII this is octal code 010.
</p>
<a name="index--_005cf-_0028formfeed-character_0029"></a>
<a name="index-formfeed-_0028_005cf_0029"></a>
</dd>
<dt><kbd>backslash-f</kbd></dt>
<dd><p>Mnemonic for FormFeed; for ASCII this is octal code 014.
</p>
<a name="index--_005cn-_0028newline-character_0029"></a>
<a name="index-newline-_0028_005cn_0029"></a>
</dd>
<dt><kbd>\n</kbd></dt>
<dd><p>Mnemonic for newline; for ASCII this is octal code 012.
</p>
<a name="index--_005cr-_0028carriage-return-character_0029"></a>
<a name="index-carriage-return-_0028backslash_002dr_0029"></a>
</dd>
<dt><kbd>\r</kbd></dt>
<dd><p>Mnemonic for carriage-Return; for ASCII this is octal code 015.
</p>
<a name="index--_005ct-_0028tab_0029"></a>
<a name="index-tab-_0028_005ct_0029"></a>
</dd>
<dt><kbd>\t</kbd></dt>
<dd><p>Mnemonic for horizontal Tab; for ASCII this is octal code 011.
</p>
<a name="index--_005cddd-_0028octal-character-code_0029"></a>
<a name="index-octal-character-code-_0028_005cddd_0029"></a>
</dd>
<dt><kbd>\ <var>digit</var> <var>digit</var> <var>digit</var></kbd></dt>
<dd><p>An octal character code.  The numeric code is 3 octal digits.
For compatibility with other Unix systems, 8 and 9 are accepted as digits:
for example, <code>\008</code> has the value 010, and <code>\009</code> the value 011.
</p>
<a name="index--_005cxd_002e_002e_002e-_0028hex-character-code_0029"></a>
<a name="index-hex-character-code-_0028_005cxd_002e_002e_002e_0029"></a>
</dd>
<dt><kbd>\<code>x</code> <var>hex-digits...</var></kbd></dt>
<dd><p>A hex character code.  All trailing hex digits are combined.  Either upper or
lower case <code>x</code> works.
</p>
<a name="index--_005c_005c-_0028_005c-character_0029"></a>
<a name="index-backslash-_0028_005c_005c_0029"></a>
</dd>
<dt><kbd>\\</kbd></dt>
<dd><p>Represents one &lsquo;<samp>\</samp>&rsquo; character.
</p>
<a name="index--_005c_0022-_0028doublequote-character_0029"></a>
<a name="index-doublequote-_0028_005c_0022_0029"></a>
</dd>
<dt><kbd>\&quot;</kbd></dt>
<dd><p>Represents one &lsquo;<samp>&quot;</samp>&rsquo; character.  Needed in strings to represent
this character, because an unescaped &lsquo;<samp>&quot;</samp>&rsquo; would end the string.
</p>
</dd>
<dt><kbd>\ <var>anything-else</var></kbd></dt>
<dd><p>Any other character when escaped by <kbd>\</kbd> gives a warning, but
assembles as if the &lsquo;<samp>\</samp>&rsquo; was not present.  The idea is that if
you used an escape sequence you clearly didn&rsquo;t want the literal
interpretation of the following character.  However <code>as</code> has no
other interpretation, so <code>as</code> knows it is giving you the wrong
code and warns you of the fact.
</p></dd>
</dl>

<p>Which characters are escapable, and what those escapes represent,
varies widely among assemblers.  The current set is what we think
the BSD 4.2 assembler recognizes, and is a subset of what most C
compilers recognize.  If you are in doubt, do not use an escape
sequence.
</p>
<hr>
<div class="header">
<p>
Next: <a href="Chars.html#Chars" accesskey="n" rel="next">Chars</a>, Up: <a href="Characters.html#Characters" accesskey="u" rel="up">Characters</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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