Linux Shells by Example

tr—translates characters

tr [ –cds ] [ string1 [ string2 ] ]

tr copies the standard input to the standard output with substitution or deletion of selected characters. Input characters found in string1 are mapped into the corresponding characters of string2. The forward slash can be used with an octal digit to represent the ASCII code. When string2 (with any repetitions of characters) contains fewer characters than string1, characters in string1 with no corresponding character in string2 are not translated. Octal values for characters may be used when preceded with a backslash:

\11   Tab
\12   New line
\042  Single quote
\047  Double quote

Example A.65.

1 tr 'A' 'B' < filex 2 tr '[A-Z]' '[a-z]' < filex 3 tr -d ' ' < filex 4 tr -s '\11' '\11' ...