tr
translate characters
TLDR
Replace all occurrences of a character in a file, and print the result
Replace all occurrences of a character from another command's output
Map each character of the first set to the corresponding character of the second set
Delete all occurrences of the specified set of characters from the input
Compress a series of identical characters to a single character
Translate the contents of a file to upper-case
Strip out non-printable characters from a file
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 may be used only 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.
REPORTING BUGS
GNU coreutils online help:
<https://www.gnu.org/software/coreutils/>
Report any translation bugs to
<https://translationproject.org/team/>
COPYRIGHT
Copyright © 2022 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'
AUTHOR
Written by Jim Meyering.