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    <blockquote> <p>above is my c code for reading a table from a file.In that ..last value is printing 2 times !!!</p> </blockquote> <p>The last value is printing two times due to the structure of the file reading loop. The <code>eof()</code> flag is not set until an attempt is made to read past the end of the file. When <code>fscanf()</code> reads the last two <code>long</code>s from the last line of the file <code>eof()</code> is not yet set but the next call to <code>fscanf()</code> fails and sets <code>eof()</code> but the result of <code>fscanf()</code> is not queried immediately, resulting the use of the previously extracted <code>long</code>s: check the result of all read operations immediately.</p> <hr> <p>A possible solution is to read a line at a time, using <a href="http://en.cppreference.com/w/c/io/fgets" rel="nofollow"><code>fgets()</code></a>, and then use <a href="http://en.cppreference.com/w/c/io/fscanf" rel="nofollow"><code>sscanf()</code></a> to extract the <code>long</code> value(s) from the read line. If <code>fscanf()</code> is used, it would read past the new-line character to locate the second requested <code>long</code>, which is not the desired behaviour.</p> <p>For example:</p> <pre><code>char line[1024]; while (fgets(line, 1024, fin)) { /* Assign appropriate default values. sscanf() does not modify its arguments for which it has no value to assign. So if 'line' has a single long value data[1] will be zero. */ long data[2] = { 0, 0 }; /* You can use 'result' if you require to take particular action if it reads only 1, or 0, items. */ int result = sscanf(line, "%ld %ld", &amp;data[0], &amp;data[1]); printf("\n%ld %ld",data[0],data[1]); } </code></pre> <hr> <p>(<em>in response to question update</em>) To differentiate between lines where second value is missing:</p> <blockquote> <p>2</p> </blockquote> <p>and lines where first value is missing:</p> <blockquote> <p>57</p> </blockquote> <p>a valid range (or some other criteria) is required to determine which value (the first or second) was missing from the line:</p> <pre><code>int result = sscanf(line, "%ld %ld", &amp;data[0], &amp;data[1]); if (1 == result) { if (data[0] &gt;= 1 &amp;&amp; data[0] &lt;= 9) { printf("\n%ld 0", data[0]); } else { /* Read value was the second value. */ printf("\n%ld %ld", ++last_first_value, data[0]); } } </code></pre> <p>where <code>last_first_value</code> is a <code>long</code> that stores the current value of the first value (either the last successfully read first value or computed from the last successfully read first value). </p>
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    1. POfile handling in c : can not read proper in table format data
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    1. COthe output is something like... 1 34 2 34 3 45 4 45 5 67 and in second case : 1 34 57 34 3 45 4 45 5 67 (odd numers are 1st column and even are second)
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    2. COstill facing problems where the "FIRST" value is missing...It is taking the second one as a FIRST..and gives 0 to second one... and as it is just example table... In real one the data is about 5-7000 lines,may be the column number also increase.
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    3. COThat code update (for checking first value missing) is wrong. `sscanf` will skip past any whitespace. You need to check characters on the line itself: `if (line[0] >= '1' && line[0] <= '9')`. A better way would be to check `if (!isspace(line[0]))`. I would have also put the correct numbers back into the `data` array if I was going to use them for anything.
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