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.
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 through char2. If char1 does not sort before char2, produce an error.
-
[
char1-char2
]
Same as char1-char2 if both strings use this.
-
[
char
*]
In string2, expand char to the length of string1.
-
[
char*number
]
Expand char to number occurrences.
[x*4]
expands toxxxx
, for instance.-
[
:class
:]
Expand to all characters in class, where class can be:
-
alnum
Letters and digits
-
alpha
Letters
-
blank
Whitespace
-
cntrl
Control characters
-
digit
Digits
-
graph
Printable characters except space
-
lower
Lowercase letters
-
print
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 (ASCII code 012):
tr ' ' '\012' < file
Strip ...
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