bsd man page for tr

TR(1)							      General Commands Manual							     TR(1)

NAME
       tr - translate characters

SYNOPSIS
       tr [ -cds ] [ string1 [ string2 ] ]

DESCRIPTION
       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 corresponding characters of string2.  When string2 is short it is padded to the length of string1 by  duplicat-
       ing  its  last character.  Any combination of the options -cds may be used: -c complements the set of characters in string1 with respect to
       the universe of characters whose ASCII codes are 01 through 0377 octal; -d deletes all input characters in string1; -s squeezes all strings
       of repeated output characters that are in string2 to single characters.

       In either string the notation a-b means a range of characters from a to b in increasing ASCII order.  The character `' followed by 1, 2 or
       3 octal digits stands for the character whose ASCII code is given by those digits.  A `' followed 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 '12' <file1 >file2

SEE ALSO
       ed(1), ascii(7), expand(1)

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

7th Edition							  April 29, 1985							     TR(1)