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getline [C++ Reference]
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<h2><a name="getline" id="getline">getline</a></h2>
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<p>
Syntax:
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<pre class="c code c++" style="font-family:monospace;"> istream<span class="sy0">&</span> istream<span class="sy0">::</span><span class="me2">getline</span><span class="br0">(</span> <span class="kw4">char</span><span class="sy0">*</span> buffer<span class="sy0">,</span> streamsize num <span class="br0">)</span><span class="sy0">;</span>
istream<span class="sy0">&</span> istream<span class="sy0">::</span><span class="me2">getline</span><span class="br0">(</span> <span class="kw4">char</span><span class="sy0">*</span> buffer<span class="sy0">,</span> streamsize num<span class="sy0">,</span> <span class="kw4">char</span> delim <span class="br0">)</span><span class="sy0">;</span></pre>
<p>
The getline() function is used with input streams. The version without a char delim argument effectively sets the delimiter to a newline character. getline() reads characters into buffer until either:
</p>
<ul>
<li class="level1"><div class="li"> num - 1 characters have been read,</div>
</li>
<li class="level1"><div class="li"> an <acronym title="End of file">EOF</acronym> is encountered,</div>
</li>
<li class="level1"><div class="li"> or, until the character delim is read. The delim character is not put into buffer.</div>
</li>
</ul>
<p>
If the delim character (newline normally) is not read, the input stream is set to a <a href="../io/fail.html" class="wikilink1" title="io:fail">failure state</a>.
</p>
<p>
For example, the following code uses the getline function to display the first 99 characters (one character is reserved for null-termination) or one line at a time from a text file – whichever comes first – (until <acronym title="End of file">EOF</acronym> or a line longer than 99 characters is encountered):
</p>
<pre class="c code c++" style="font-family:monospace;"> ifstream fin<span class="br0">(</span><span class="st0">"tmp.dat"</span><span class="br0">)</span><span class="sy0">;</span>
<span class="kw4">int</span> MAX_LENGTH <span class="sy0">=</span> <span class="nu0">100</span><span class="sy0">;</span>
<span class="kw4">char</span> line<span class="br0">[</span>MAX_LENGTH<span class="br0">]</span><span class="sy0">;</span>
<span class="kw1">while</span><span class="br0">(</span> fin.<span class="me1">getline</span><span class="br0">(</span>line<span class="sy0">,</span> MAX_LENGTH<span class="br0">)</span> <span class="br0">)</span> <span class="br0">{</span>
<a href="http://www.opengroup.org/onlinepubs/009695399/functions/cout.html"><span class="kw3">cout</span></a> <span class="sy0"><<</span> <span class="st0">"read line: "</span> <span class="sy0"><<</span> line <span class="sy0"><<</span> endl<span class="sy0">;</span>
<span class="br0">}</span></pre>
<p>
If you'd like to read lines from a file into strings instead of character arrays, consider using the <a href="../string/getline.html" class="wikilink1" title="string:getline">string getline</a> function.
</p>
<p>
Those using a Microsoft compiler may find that getline reads an extra character, and should consult the documentation on the <a href="http://support.microsoft.com/kb/240015" class="urlextern" title="http://support.microsoft.com/kb/240015" rel="nofollow">Microsoft getline bug</a>.
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Related Topics: <a href="../io/gcount.html" class="wikilink1" title="io:gcount">gcount</a>, <a href="../io/get.html" class="wikilink1" title="io:get">get</a>, <a href="../string/getline.html" class="wikilink1" title="string:getline">string getline</a>, <a href="../io/ignore.html" class="wikilink1" title="io:ignore">ignore</a>, <a href="../io/read.html" class="wikilink1" title="io:read">read</a>
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