Name
tr
Synopsis
tr [options
] [string1
[string2
]
Translates characters; copies standard input to standard output, substituting characters from string1
to string2
, or deleting characters in string1
.
Options
- -c
Complement characters in
string1
with respect to ASCII 001-377.- -d
Delete characters in
string1
from output.- -s
Squeeze out repeated output characters in
string2
.- -u
Guarantee that any output is unbuffered.
Special characters
Include brackets ([ ]
) where shown.
- \a
^G (bell).
- \b
^H (backspace).
- \f
^L (form feed).
- \n
^J (newline).
- \r
^M (carriage return).
- \t
^I (tab).
- \v
^K (vertical tab).
-
\
nnn
Character with octal value nnn.
- \\
Literal backslash.
-
char1
-
char2
All characters in the range
char1
throughchar2
. Ifchar1
doesn’t sort beforechar2
, produce an error.-
[
char1
-
char2
]
Same as
char1
-char2
if both strings use this.-
[
char
*]
In
string2
, expandchar
to the length ofstring1
.-
[
char
*
number
]
Expand
char
to number occurrences.[x*4]
expands toxxxx
, for instance.-
[:
class
:]
Expand to all characters in
class
, whereclass
can be:- alnum
Letters and digits
- alpha
Letters
- blank
Whitespace
- cntrl
Control characters
- digit
Digits
- graph
Printable characters except space
- lower
Lowercase letters
Printable characters
- punct
Punctuation
- space
Whitespace (horizontal or vertical)
- upper
Uppercase letters
- xdigit
Hexadecimal digits
-
[=
char
=]
The class of characters in which
char
belongs.
Examples
Change uppercase to lowercase in a file:
$cat
file
| tr '[A-Z]' '[a-z]'
Turn spaces into newlines ...
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