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 (runes).  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 Complement string1: replace it with a lexicographically ordered list of all other characters.

­-d Delete from input all characters in string1.

­-s Squeeze repeated output characters that occur in ­string2 to single characters. 

In either string a noninitial sequence -x, where ­x is any character (possibly quoted), stands for a range of characters: a possibly empty sequence of codes running from the successor of the previous code up through the code for x. The character ­\ followed by 1, 2 or 3 octal digits stands for the character whose 16-bit value is given by those digits.  The character sequence ­\x followed by 1, 2, 3, or 4 hexadecimal digits stands for the character whose 16-bit value is given by those digits.  A ­\ followed by any other character stands for that character. 

EXAMPLES

Replace all upper-case ASCII letters by lower-case. 

tr A-Z a-z <mixed >lower

Create 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.  ­String2 is given as a quoted newline. 

tr -cs A-Za-z ’
’ <file1 >file2

SOURCE

­/sys/src/cmd/tr.c

SEE ALSO

sed(1)

Plan 9  —  December 11, 1999