tr

Examples (TL;DR)

• Replace all occurrences of a character in a file, and print the result: tr find_character replace_character < filename
• Replace all occurrences of a character from another command's output: echo text | tr find_character replace_character
• Map each character of the first set to the corresponding character of the second set: tr 'abcd' 'jkmn' < filename
• Delete all occurrences of the specified set of characters from the input: tr -d 'input_characters' < filename
• Compress a series of identical characters to a single character: tr -s 'input_characters' < filename
• Translate the contents of a file to upper-case: tr "[:lower:]" "[:upper:]" < filename
• Strip out non-printable characters from a file: tr -cd "[:print:]" < filename

tldr.sh

Synopsis

tr [OPTION]... SET1 [SET2]

Description

Translate, squeeze, and/or delete characters from standard input, writing to standard output.

-c, -C, --complement

use the complement of SET1

-d, --delete

delete characters in SET1, do not translate

-s, --squeeze-repeats

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

-t, --truncate-set1

first truncate SET1 to length of SET2

--help

display this help and exit

--version

output version information and exit

SETs 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 SET2, copies of CHAR until length of SET1

[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 SET1 and SET2 appear. -t may be used only when translating.  SET2 is extended to length of SET1 by repeating its last character as necessary.  Excess characters of SET2 are ignored.  Only [:lower:] and [:upper:] are guaranteed to expand in ascending order; used in SET2 while translating, they may only be used in pairs to specify case conversion.  -s uses the last specified SET, and occurs after translation or deletion.

Author

Written by Jim Meyering.

Reporting Bugs

GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>

Copyright

Copyright © 2019 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.

See Also

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

Referenced By

pass(1), perlop(1), petcat(1), proc(5), rumakeindex(1), sed(1), shtool-table(1).