TR(1) 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 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
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 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
SEE ALSO
ed(1), ascii(7)
BUGS
Won't handle ASCII NUL in string1 or string2; always deletes
NUL from input.