Copyright ©

tr - Unix, Linux Command

previous next



tr - translate or delete characters


tr [OPTION]... SET1 [SET2]


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
  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
  all characters from CHAR1 to CHAR2 in ascending order
  in SET2, copies of CHAR until length of SET1
  REPEAT copies of CHAR, REPEAT octal if starting with 0
  all letters and digits
  all letters
  all horizontal whitespace
  all control characters
  all digits
  all printable characters, not including space
  all lower case letters
  all printable characters, including space
  all punctuation characters
  all horizontal or vertical whitespace
  all upper case letters
  all hexadecimal digits
  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.


Written by Jim Meyering.


Report bugs to <>.


Copyright © 2006 Free Software Foundation, Inc.
This is free software. You may redistribute copies of it under the terms of the GNU General Public License <>. There is NO WARRANTY, to the extent permitted by law.


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.
previous next

Copyright ©