TR(1) (Directory and File Management Utilities) 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. 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 001 through 377 octal.
-d Deletes all input characters in string1.
-s Squeezes all strings of repeated output characters
that are in string2 to single characters.
The following abbreviation conventions may be used to
introduce ranges of characters or repeated characters into
the strings:
[a-z] Stands for the string of characters whose ASCII
codes run from character a to character z,
inclusive.
[a*n] Stands for n repetitions of a. If the first digit
of n is 0, n is considered octal; otherwise, n is
taken to be decimal. A zero or missing n is taken
to be huge; this facility is useful for padding
string2.
The escape character \ may be used as in the shell to remove
special meaning from any character in a string. In
addition, \ followed by 1, 2, or 3 octal digits stands for
the character whose ASCII code is given by those digits.
Page 1 May 1989
TR(1) (Directory and File Management Utilities) TR(1)
EXAMPLE
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 strings are quoted to
protect the special characters from interpretation by the
shell; 012 is the ASCII code for newline.
tr -cs "[A-Z][a-z]" "[\012*]" <file1 >file2
SEE ALSO
ed(1), sh(1).
ascii(5) in the Programmer's Reference Manual.
BUGS
Will not handle ASCII NUL in string1 or string2; always
deletes NUL from input.
Page 2 May 1989