TR

Section: User Commands (1)
Updated: February 2026
Index Return to Main Contents

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NAME

tr - translate or delete characters  

SYNOPSIS

tr [,OPTION/]... ,STRING1 /[,STRING2/]  

DESCRIPTION

Translate, squeeze, and/or delete characters from standard input, writing to standard output. STRING1 and STRING2 specify arrays of characters ARRAY1 and ARRAY2 that control the action.

X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#t-c'-c, -C, --complementX'tty: link'

use the complement of ARRAY1

X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#t-d'-d, --deleteX'tty: link'

delete characters in ARRAY1, do not translate

X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#t-s'-s, --squeeze-repeatsX'tty: link'

replace each sequence of a repeated character that is listed in the last specified ARRAY, with a single occurrence of that character

X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#t-t'-t, --truncate-set1X'tty: link'

first truncate ARRAY1 to length of ARRAY2

X'tty: link https://www.gnu.org/software/coreutils/tr#t-help'--helpX'tty: link'

display this help and exit

X'tty: link https://www.gnu.org/software/coreutils/tr#t-version'--versionX'tty: link'

output version information and exit

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

NNN

character with octal value NNN (1 to 3 octal digits)

backslash

a

audible BEL

b

backspace

f

form feed

n

new line

r

return

t

horizontal tab

v

vertical tab

CHAR1-CHAR2

all characters from CHAR1 to CHAR2 in ascending order

[CHAR*]

in ARRAY2, copies of CHAR until length of ARRAY1

[CHAR*REPEAT]

REPEAT copies of CHAR, REPEAT octal if starting with 0

[: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

[=CHAR=]

all characters which are equivalent to CHAR

Translation occurs if -d is not given and both STRING1 and STRING2 appear. -t is only significant when translating. ARRAY2 is extended to length of ARRAY1 by repeating its last character as necessary. Excess characters of ARRAY2 are ignored. Character classes expand in unspecified order; while translating, '[:lower:]' and '[:upper:]' may be used in pairs to specify case conversion. Squeezing occurs after translation or deletion. Arguments like '[...]' should be quoted, to avoid potential shell globbing.  

BUGS

Full support is available only for safe singl-byte locales, in which every possible input byte represents a single character. The C locale is safe in GNU systems, so you can avoid this issue in the shell by running LC_ALL=C tr instead of plain tr.  

AUTHOR

Written by Jim Meyering.  

REPORTING BUGS

Report bugs to: bug-coreutils@gnu.org

Report Gentoo bugs to: https://bugs.gentoo.org/
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
Report any translation bugs to <https://translationproject.org/team/>  

SEE ALSO

Full documentation <https://www.gnu.org/software/coreutils/tr>
or available locally via: info aq(coreutils) tr invocationaq

Packaged by Gentoo (9.10 (p0))
Copyright © 2026 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

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Index

NAME

SYNOPSIS

DESCRIPTION

BUGS

AUTHOR

REPORTING BUGS

SEE ALSO