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     TR(1)                                                       TR(1)

          tr - translate characters

          tr [ -cds ] [ string1 [ string2 ] ]

          Tr copies the standard input to the standard output with
          substitution or deletion of selected characters.  Input
          characters found in string1 are mapped into the correspond-
          ing characters of string2. When string2 is short it is pad-
          ded to the length of string1 by duplicating its last charac-
          ter.  Any combination of the options -cds may be used:

          -c   complement the set of characters in string1 with
               respect to the universe of characters whose ASCII codes
               are 01 through 0377

          -d   delete all input characters in string1

          -s   squeeze all strings of repeated output characters that
               are in string2 to single characters

          In either string the notation a-b means a range of charac-
          ters from a to b in increasing ASCII order.  The character
          `\' followed by 1, 2 or 3 octal digits stands for the char-
          acter whose ASCII code is given by those digits.  A `\' fol-
          lowed by any other character stands for that character.

          The following example creates a list of all the words in
          `file1' one per line in `file2', where a word is taken to be
          a maximal string of alphabetics.  The second string is
          quoted to protect `\' from the Shell.  012 is the ASCII code
          for newline.

               tr -cs A-Za-z '\012' <file1 >file2

          ed(1), ascii(7)

          Won't handle ASCII NUL in string1 or string2; always deletes
          NUL from input.