tr/SEARCHLIST/REPLACEMENTLIST/cds
y/SEARCHLIST/REPLACEMENTLIST/cds

    Transliterates all occurrences of the characters found in the search list with the corresponding character in the replacement list. It returns the number of characters replaced or deleted. If no string is specified via the =~ or !~ operator, the $_ string is transliterated. (The string specified with =~ must be a scalar variable, an array element, a hash element, or an assignment to one of those, i.e., an lvalue.)

    A character range may be specified with a hyphen, so tr/A-J/0-9/ does the same replacement as tr/ACEGIBDFHJ/0246813579/. For sed devotees, y is provided as a synonym for tr. If the SEARCHLIST is delimited by bracketing quotes, the REPLACEMENTLIST has its own pair of quotes, which may or may not be bracketing quotes, e.g., tr[A-Z][a-z] or tr(+\-*/)/ABCD/.

    Note that tr does not do regular expression character classes such as \d or [:lower:]. The <tr> operator is not equivalent to the tr(1) utility. If you want to map strings between lower/upper cases, see perlfunc/lc and perlfunc/uc, and in general consider using the s operator if you need regular expressions.

    Note also that the whole range idea is rather unportable between character sets--and even within character sets they may cause results you probably didn't expect. A sound principle is to use only ranges that begin from and end at either alphabets of equal case (a-e, A-E), or digits (0-4). Anything else is unsafe. If in doubt, spell out the character sets in full.

    Options:

c	Complement the SEARCHLIST.
    d	Delete found but unreplaced characters.
    s	Squash duplicate replaced characters.