tr - translate, squeeze, and/or delete characters

tr copies the standard input to the standard output with substitution or deletion of selected characters. Input characters in set1 are mapped to corresponding characters in set2.

-c, --complement

Complement set1.

-d, --delete

Delete characters in set1 but do not translate.

-s, --squeeze-repeats

Replace sequences of the same character with one.

-t, --truncate-set1

Truncate set1 to the length of set2.

sets are specified as strings of characters. Most represent themselves. Interpreted sequences are:

\nnn

character with octal value nnn

\xnn

character with hexadecimal value nn

\\

backslash

\a

alert

\b

backpace

\f

form feed

\r

return

\t

horizontal tab

\v

vertical tab

\E

escape

c1-c2

all characters from c1 to c2 in ascending order

[c1-c2]

same as c1-c2 if both sets use this form

[[c*]]

in set2, copies of \ac\a until length of set1

[[c*n]]

\an\a copies of \ac\a

[[:alnum:]]

all letters and digits

[[:alpha:]]

all letters

[[:blank:]]

all horizontal whitespace

[[:cntrl:]]

all control characters

[[:digit:]]

all digits

[[:graph:]]

all printable characters, not including space

[[:lower:]]

all lower case letters

[[:print:]]

all printable characters, including space

[[:punct:]]

all punctuation characters

[[:space:]]

all horizontal or vertical whitespace

[[:upper:]]

all upper case letters

[[:xdigit:]]

all hexadecimal digits

[[=c=]]

all characters which are equivalent to \ac\a

Translation occurs if -d is not given and both set1 and set2 appear. -t may be used only when translating. set2 is extended to the length of set1 by repeating its last character as necessary. Excess characters in set2 are ignored. Only [:lower:] and [:upper:] are guaranteed to expand in ascending order. They may only be used in pairs to specify case conversion. -s uses set1 if neither translating nor deleting, otherwise squeeze uses set2 and occurs after translation or deletion.

sed(1), ascii(5)

version

tr (AT&T Research) 2012-05-31

author

Glenn Fowler <gsf@research.att.com>

author

David Korn <dgk@research.att.com>

copyright

Copyright © 1992-2012 AT&T Intellectual Property

license

http://www.eclipse.org/org/documents/epl-v10.html