|  | Uniq copies the input file, or the standard input, to the standard
    output, comparing adjacent lines. In the normal case, the second
    and succeeding copies of repeated lines are removed. Repeated
    lines must be adjacent in order to be found. −u    Print unique lines.
 −d    Print (one copy of) duplicated lines.
 −c    Prefix a repetition count and a tab to each output line. Implies
    −u and −d.
 −num   The first num fields together with any blanks before each
    are ignored. A field is defined as a string of non-space, non-tab
    characters separated by tabs and spaces from its neighbors.
 +num   The first num characters are ignored. Fields are skipped before
    characters.
 
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