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The following scenarios can result in undefined behavior. (See undefined behavior 151156.)

•  Receiving input from a stream directly following an output to that stream without an intervening call to fflush(), fseek(), fsetpos(), or rewind() if the file is not at end-of-file
•  Outputting to a stream after receiving input from that stream without a call to fseek(), fsetpos(), or rewind() if the file is not at end-of-file

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