Name

tr — translate or delete characters

Synopsis

tr [OPTION...] SET1 [SET2]

DESCRIPTION

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

−c, −C, −−complement

first complement SET1

−d, −−delete

delete characters in SET1, do not translate

−s, −−squeeze−repeats

replace each input sequence of a repeated character that is listed in SET1 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 SET1 if not translating nor deleting; else squeezing uses SET2 and occurs after translation or deletion.

AUTHOR

Written by Jim Meyering.

REPORTING BUGS

Report bugs to <bug−coreutils@gnu.org>.

SEE ALSO

The full documentation for tr is maintained as a Texinfo manual. If the info and tr programs are properly installed at your site, the command

info tr

should give you access to the complete manual.

COPYRIGHT

Copyright © 2008 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://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.