9.1 tr: Translate, squeeze, and/or delete characters


tr [option]… string1 [string2]

tr copies standard input to standard output, performing one of the following operations:

The string1 and string2 operands define arrays of characters array1 and array2. By default array1 lists input characters that tr operates on, and array2 lists corresponding translations. In some cases the second operand is omitted.

The program accepts the following options. Also see Common options. Options must precede operands.


Instead of array1, use its complement (all characters not specified by string1), in ascending order. Use this option with caution in multibyte locales where its meaning is not always clear or portable; see Specifying arrays of characters.


Delete characters in array1; do not translate.


Replace each sequence of a repeated character that is listed in the last specified array, with a single occurrence of that character.


Truncate array1 to the length of array2.

An exit status of zero indicates success, and a nonzero value indicates failure.