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POFile I/O logic with a while statement, how would this code be expected to behave?
 

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  1. POFile I/O logic with a while statement, how would this code be expected to behave?
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    <p>I'm trying to understand some differences in file i/o techniques. Suppose I have the following code:</p> <pre><code>FILE *work_fp; char record[500] = {0}; while(!feof(work_fp)) { static int first = 1; fgets(record, 200, work_fp); if (first) { var1 = 2; length += var1; } first = 0; if (feof(work_fp)) { continue; } if((int)strlen(record) &lt; length) { fclose(work_fp); std::ostringstream err; err &lt;&lt; "ERROR -&gt; Found a record with fewer bytes than required in file." &lt;&lt; std::endl; throw std::runtime_error(err.str()); } const int var2 = 1; if(memcmp(argv[1], record + var2, 3) == 0) { load_count_struct(record, var1); } } </code></pre> <p>I'm not seeing how the second <code>if</code> argument can be true.</p> <pre><code>if (feof(work_fp)) { continue; } </code></pre> <p>If <code>feof(work_fp)</code> is true wouldn't the <code>while</code> argument be false? Then the continue could never get called?</p> <p>FOLLOW UP QUESTION:</p> <p>Ok, I see how <code>fgets</code> can cause <code>work_fp</code> to reach <code>eof</code> conditions.</p> <p>Suppose I want to try and implement this another way. Using <code>getline()</code>, for example.</p> <pre><code>std::string data(file); std::ifstream in(data.c_str()); if (!in.is_open()) { std::ostringstream err; err &lt;&lt; "Cannot open file: " &lt;&lt; file &lt;&lt; std::endl; throw std::runtime_error(err.str()); } std::string buffer = ""; std::string record = ""; while (getline(in, buffer)) { static int first = 1; if (first) { var1 = 2; length += var1; } first = 0; if (//What should go here?!?) { break; } // etc... } </code></pre> <p>Any suggestions? I'm thinking</p> <pre><code>if (buffer == std::string::npos) </code></pre> <p>no?</p>
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