tr(C)
tr --
translate characters
Syntax
tr [ -cs ] string1 string2
tr -s [ -c ] string1
tr -d [ -c ] string1
tr -ds [ -c ] string1
string2
Description
The tr command 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.
tr understands the option -- to be the option
delimiter. string1 and string2 are defined as
two strings of characters. In addition to literal strings of
characters, tr understands the following constructs:
\octal-
backslash escaped sequence followed by 1, 2 or 3 octal digits
represents the character whose ASCII code is defined by
that sequence of digits
\character-
backslash escaped sequence for any of the file format notation
(\\, \a, \b, \f, \n, \r, \t, \v).
c-c-
range of collating elements between the range endpoints, inclusive
(as defined by the current setting of the LC_COLLATE locale category).
The characters or collating elements in the range are placed in the
array in ascending collation sequence.
The first endpoint must precede the second endpoint in the
current collation order.
[:class:]-
a character belonging to the LC_CTYPE character class.
Supported classes are:
alnum blank digit lower punct upper
alpha cntrl graph print space xdigit
All of these are acceptable when specified in string1.
When both the -d and -s options are specified,
all of the class names are acceptable in string2. If the
two options are not specified, only lower and
upper are acceptable in string2. (See
localedef(C)
for further information.)
[=equiv=]-
Characters belonging to the LC_COLLATE equivalence class
equiv. An equivalence class expression can be used in
string1, and in string2 when the command line
includes the -d and -s options. (See
localedef(C)
for further information.)
[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 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-Za-z" "[\012]" <file1 >file2
This example translates all lower-case characters in file1
to upper-case and writes the output to file2.
tr "[:lower:]" "[:upper:]" < file1 > file2
See also
ascii(M),
ed(C),
locale(M),
localedef(C),
sh(C)
Standards conformance
tr is conformant with:
ISO/IEC DIS 9945
2:1992, Information technology Portable Operating System Interface (POSIX) Part 2: Shell and Utilities (IEEE Std 1003.21992);
AT&T SVID Issue 2;
X/Open CAE Specification, Commands and Utilities, Issue 4, 1992.
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003