TR(1)
NAME
tr − translate characters
USAGE
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.
In either string, the notation a−b means a range of characters from a to b in increasing ASCII order. A backslash (\) followed by 1, 2, or 3 octal digits stands for the character whose ASCII code is given by those digits. A backslash followed by any other character stands for that character.
OPTIONS
−c Complement the set of characters in string1 with respect to the universe of characters whose ASCII codes are 01 through 0377 octal.
−d Delete all input characters in string1.
−s Squeeze all strings of repeated output characters in string2 to single characters.
EXAMPLE
The example below 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 the backslash from the Shell. The 012 is the ASCII code for newline.
tr −cs A−Za−z ´\012´ <file1 >file2
CAUTIONS
Tr cannot handle ASCII NUL in string1 or string2. It always deletes the NUL from input.