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    <p>Read to the end of the file, then seek backwards until you find ten newlines, and then read forward to the end taking into consideration various encodings. Be sure to handle cases where the number of lines in the file is less than ten. Below is an implementation (in C# as you tagged this), generalized to find the last <code>numberOfTokens</code> in the file located at <code>path</code> encoded in <code>encoding</code> where the token separator is represented by <code>tokenSeparator</code>; the result is returned as a <code>string</code> (this could be improved by returning an <code>IEnumerable&lt;string&gt;</code> that enumerates the tokens).</p> <pre><code>public static string ReadEndTokens(string path, Int64 numberOfTokens, Encoding encoding, string tokenSeparator) { int sizeOfChar = encoding.GetByteCount("\n"); byte[] buffer = encoding.GetBytes(tokenSeparator); using (FileStream fs = new FileStream(path, FileMode.Open)) { Int64 tokenCount = 0; Int64 endPosition = fs.Length / sizeOfChar; for (Int64 position = sizeOfChar; position &lt; endPosition; position += sizeOfChar) { fs.Seek(-position, SeekOrigin.End); fs.Read(buffer, 0, buffer.Length); if (encoding.GetString(buffer) == tokenSeparator) { tokenCount++; if (tokenCount == numberOfTokens) { byte[] returnBuffer = new byte[fs.Length - fs.Position]; fs.Read(returnBuffer, 0, returnBuffer.Length); return encoding.GetString(returnBuffer); } } } // handle case where number of tokens in file is less than numberOfTokens fs.Seek(0, SeekOrigin.Begin); buffer = new byte[fs.Length]; fs.Read(buffer, 0, buffer.Length); return encoding.GetString(buffer); } } </code></pre>
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    1. POGet last 10 lines of very large text file > 10GB
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    1. USjason
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    1. POGet last 10 lines of very large text file > 10GB
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    1. COThat assumes an encoding where the size of the character is always the same. It could get tricky in other encodings.
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      1. USJon Skeet
    2. COAnd, as Skeet informed me once, the Read method is not guaranteed to read the requested number of bytes. You have to check the return value to determine if you're done reading...
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      1. USWill
    3. CO@Jon: Variable-length character encoding. Oh joy.
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