22 lines
500 B
Ruby
22 lines
500 B
Ruby
class File
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#read last n lines of a file. useful for getting last part of a big log file.
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def tail(n)
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buffer = 1024
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idx = (size - buffer).abs
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chunks = []
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lines = 0
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begin
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seek(idx)
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chunk = read(buffer)
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lines += chunk.count("\n")
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chunks.unshift chunk
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idx -= buffer
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end while lines < ( n + 1 ) && pos != 0
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tail_of_file = chunks.join('')
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ary = tail_of_file.split(/\n/)
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lines_to_return = ary[ ary.size - n, ary.size - 1 ]
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end
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end |