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.
-c, -C, --complement
use the complement of ARRAY1
-d, --delete
delete characters in ARRAY1, do not translate
-s, --squeeze-repeats
replace each sequence of a repeated character that is listed in the last specified ARRAY,
with a single occurrence of that character
-t, --truncate-set1
first truncate ARRAY1 to length of ARRAY2
--help display this help and exit
--version
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.
BUGS
Full support is available only for safe single-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
GNU coreutils online help: [https://www.gnu.org/software/coreutils/] 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 '(coreutils) tr invocation'
Packaged by Debian (9.7-3) Copyright © 2025 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.