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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def main():
 """ Entry point for cli. """

    if sys.argv[1:]:  # called with input arguments
        copy(' '.join(sys.argv[1:]))
    elif not sys.stdin.isatty():  # piped in input
        copy(''.join(sys.stdin.readlines()).rstrip('\n'))
    else:  # paste output
        print(paste())