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@(#)tr.1 6.6 (Berkeley) 7/30/91
.Dd July 30, 1991 .Dt TR 1 .Os .Sh NAME .Nm tr .Nd Translate Characters. .Sh SYNOPSIS .Nm tr .Op Fl c .Op Fl d | Fl s .Ar string1 string2 .Sh DESCRIPTION The tr utility copies the standard input to the standard output with substitution or deletion of selected characters. The options specified and the .Ar string1 and .Ar string2 operands control translations that occur while copying characters.
p The following options are available: l -tag -width Ds t Fl c Complements the set of characters in string1 with respect to the universe of characters whose .Tn ISO 646 [4] codes are 00 through 0377 octal. t Fl d Deletes all input characters in .Ar string1 . t Fl s Squeezes all output strings of one or more instances of a single character in .Ar string2 to a single instance of that character. Input characters found in .Ar string1 are mapped into the corresponding characters of .Ar string2 . When .Ar string2 is shorter than .Ar string1 , string2 is extended to the length of .Ar string1 by duplicating the last character of .Ar string2 . If .Ar string2 is explicitly a string of zero length, .Ar string2 is padded with .Tn NUL characters. .El
p The following operands are available: l -tag -width stringx t Ar string1 t Ar string2 Translation character strings. .El
p
p If the .Fl c option is given in conjunction with the .Fl d option, then only those characters found in .Ar string1 is copied to the standard output.
p
The following conventions can be used in
.Ar string1
or
.Ar string2
or both to specify characters, character ranges, character
classes, or collating elements:
l -tag -width [[:equiv:]] t character Represents that character.
t \eoctal A backslash followed by 1, 2, or 3 octal
digits represents a character with that
encoded value.
If a \eoctal sequence is
followed by digits, the backslash and up to
three digits are interpreted to prepare a
character; subsequent digits are interpreted
as individual characters.
t \echaracter A backslash followed by any character except
an octal digit represents that character.
t [c-c] Represents the range of ordered elements
between the range endpoints, inclusive.
; as
defined by the current setting of the
setlocale() category
.Em LC_COLLATE .
The collating
elements are ordered in ascending collating
sequence, and the first endpoint shall precede
the second in the collating sequence.
t [[:class:]] Represents all characters belonging to the
defined character class.
as defined by the
current setting of the setlocale() category
.Ev LC_CTYPE .
Allowable names for class are:
l -column alpha upper lower digit xdigit -offset indent alpha upper lower digit xdigit alnum
space punct print graph cntrl
.El
p
The characters placed in ascending order.
.Em LC_COLLATE .
(Characters not defined in the
current collating sequence are ordered
according to the collation sequence's rules
for ordering of undefined characters.)
t [[=equiv=]] Represents all characters or collating (sorting)
elements belonging to the same equivalence class
as equiv.
.Em LC_COLLATE .
If
there is a secondary ordering within the
equivalence class, the characters are ordered
in ascending sequence.
Otherwise, they are
ordered after their encoded values.
t [[.cs.]] Represents a collating symbol.
Multicharacter
collating symbols shall be represented as
collating symbols to distinguish them from a
string of the same characters.
t [x*n] Represents n repeated occurrences of the
character or collating symbol x.
This
expression is only valid when it occurs in
.Ar string2 .
If n is omitted or is zero, it is
be interpreted as large enough to extend the
.Ar string2 Ns -based
sequence to the length of the
.Ar string1 Ns -based
sequence.
If n has a leading
zero, it shall be interpreted as an octal
value.
Otherwise, it shall be interpreted as
a decimal value.
.El
p Characters belonging to an equivalence class occupy the same position in the sequence, ordered after secondary ordering.
p The .Nm tr utility exits with one of the following values: l -tag -width Ds t 0 All input was processed successfully. t 1 An error occurred. .El .Sh STANDARDS The .Nm tr utility is expected to be .St -p1003.2 compatible.
Indexes created Fri Oct 31 11:10:07 GMT 2025