term% cat index.txt 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 duplicating its last
character. Any combination of the options -cds may be used: -c comple‐
ments 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 '\012' <file1 >file2
SEE ALSO
ed(1), ascii(7)
BUGS
Won't handle ASCII NUL in string1 or string2; always deletes NUL from
input.
TR(1)