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fileio2.cpp.html
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fileio2.cpp.html
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<!DOCTYPE HTML>
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<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="GENERATOR" content="GNU source-highlight
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite">
<title>fileio2.cpp</title>
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<body style="background-color:white">
<pre><i><span style="color:#9A1900">// This program shows how C++-based file I/O works.</span></i>
<i><span style="color:#9A1900">// It will open a file, read in the first two strings, and print them to the screen.</span></i>
<b><span style="color:#000080">#include</span></b> <span style="color:#FF0000"><iostream></span>
<b><span style="color:#000080">#include</span></b> <span style="color:#FF0000"><fstream></span>
<b><span style="color:#000080">#include</span></b> <span style="color:#FF0000"><cstdlib></span>
<b><span style="color:#0000FF">using</span></b> <b><span style="color:#0000FF">namespace</span></b> std<span style="color:#990000">;</span>
<i><span style="color:#9A1900">// we want to use parameters</span></i>
<span style="color:#009900">int</span> <b><span style="color:#000000">main</span></b><span style="color:#990000">(</span><span style="color:#009900">int</span> argc<span style="color:#990000">,</span> <span style="color:#009900">char</span><span style="color:#990000">**</span> argv<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
<i><span style="color:#9A1900">// verify the correct number of parameters</span></i>
<b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>argc <span style="color:#990000">!=</span> <span style="color:#993399">2</span><span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
cout <span style="color:#990000"><<</span> <span style="color:#FF0000">"Must supply the input file name as the one and only parameter"</span> <span style="color:#990000"><<</span> endl<span style="color:#990000">;</span>
<b><span style="color:#000000">exit</span></b><span style="color:#990000">(</span><span style="color:#993399">1</span><span style="color:#990000">);</span>
<span style="color:#FF0000">}</span>
<i><span style="color:#9A1900">// attempt to open the supplied file</span></i>
<span style="color:#008080">ifstream</span> <b><span style="color:#000000">file</span></b><span style="color:#990000">(</span>argv<span style="color:#990000">[</span><span style="color:#993399">1</span><span style="color:#990000">],</span> ifstream<span style="color:#990000">::</span>binary<span style="color:#990000">);</span>
<i><span style="color:#9A1900">// report any problems opening the file and then exit</span></i>
<b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(!</span>file<span style="color:#990000">.</span><b><span style="color:#000000">is_open</span></b><span style="color:#990000">())</span> <span style="color:#FF0000">{</span>
cout <span style="color:#990000"><<</span> <span style="color:#FF0000">"Unable to open file '"</span> <span style="color:#990000"><<</span> argv<span style="color:#990000">[</span><span style="color:#993399">1</span><span style="color:#990000">]</span> <span style="color:#990000"><<</span> <span style="color:#FF0000">"'."</span> <span style="color:#990000"><<</span> endl<span style="color:#990000">;</span>
<b><span style="color:#000000">exit</span></b><span style="color:#990000">(</span><span style="color:#993399">2</span><span style="color:#990000">);</span>
<span style="color:#FF0000">}</span>
<i><span style="color:#9A1900">// read in two strings</span></i>
<span style="color:#008080">string</span> s1<span style="color:#990000">,</span> s2<span style="color:#990000">;</span>
file <span style="color:#990000">>></span> s1<span style="color:#990000">;</span>
file <span style="color:#990000">>></span> s2<span style="color:#990000">;</span>
<i><span style="color:#9A1900">// output those strings</span></i>
cout <span style="color:#990000"><<</span> s1 <span style="color:#990000"><<</span> endl<span style="color:#990000">;</span>
cout <span style="color:#990000"><<</span> s2 <span style="color:#990000"><<</span> endl<span style="color:#990000">;</span>
<i><span style="color:#9A1900">// close the file before exiting</span></i>
file<span style="color:#990000">.</span><b><span style="color:#000000">close</span></b><span style="color:#990000">();</span>
<span style="color:#FF0000">}</span>
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