TR(1)TR(1)NAMEtr - translate characters
SYNOPSIStr [ -cds ] [ string1 [ string2 ] ]
Tr copies the standard input to the standard output with substitution
or deletion of selected characters (runes). Input characters found in
string1 are mapped into the corresponding characters of string2. When
string2 is short it is padded to the length of string1 by duplicating
its last character. Any combination of the options -cds may be used:
-c Complement string1: replace it with a lexicographically ordered
list of all other characters.
-d Delete from input all characters in string1.
-s Squeeze repeated output characters that occur in string2 to sin‐
In either string a noninitial sequence -x, where x is any character
(possibly quoted), stands for a range of characters: a possibly empty
sequence of codes running from the successor of the previous code up
through the code for x. The character followed by 1, 2 or 3 octal dig‐
its stands for the character whose 16-bit value is given by those dig‐
its. The character sequence followed by 1 to 6 hexadecimal digits
stands for the character whose 21-bit value is given by those digits.
A followed by any other character stands for that character.
Replace all upper-case ASCII letters by lower-case.
tr A-Z a-z <mixed >lower
Create a list of all the words in one per line in where a word is taken
to be a maximal string of alphabetics. String2 is given as a quoted
tr-cs A-Za-z '
' <file1 >file2