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TR(1)			FreeBSD	General	Commands Manual			 TR(1)

NAME
     tr	-- translate characters

SYNOPSIS
     tr	[-csu] string1 string2
     tr	[-cu] -d string1
     tr	[-cu] -s string1
     tr	[-cu] -ds string1 string2

DESCRIPTION
     The tr utility copies the standard	input to the standard output with sub-
     stitution or deletion of selected characters.

     The following options are available:

     -c	     Complements the set of characters in string1, that	is ``-c	ab''
	     includes every character except for ``a'' and ``b''.

     -d	     The -d option causes characters to	be deleted from	the input.

     -s	     The -s option squeezes multiple occurrences of the	characters
	     listed in the last	operand	(either	string1	or string2) in the
	     input into	a single instance of the character.  This occurs after
	     all deletion and translation is completed.

     -u	     The -u option guarantees that any output is unbuffered.

     In	the first synopsis form, the characters	in string1 are translated into
     the characters in string2 where the first character in string1 is trans-
     lated into	the first character in string2 and so on.  If string1 is
     longer than string2, the last character found in string2 is duplicated
     until string1 is exhausted.

     In	the second synopsis form, the characters in string1 are	deleted	from
     the input.

     In	the third synopsis form, the characters	in string1 are compressed as
     described for the -s option.

     In	the fourth synopsis form, the characters in string1 are	deleted	from
     the input,	and the	characters in string2 are compressed as	described for
     the -s option.

     The following conventions can be used in string1 and string2 to specify
     sets of characters:

     character	Any character not described by one of the following conven-
		tions represents itself.

     \octal	A backslash followed by	1, 2 or	3 octal	digits represents a
		character with that encoded value.  To follow an octal
		sequence with a	digit as a character, left zero-pad the	octal
		sequence to the	full 3 octal digits.

     \character
		A backslash followed by	certain	special	characters maps	to
		special	values.

		\a    <alert character>
		\b    <backspace>
		\f    <form-feed>
		\n    <newline>
		\r    <carriage	return>
		\t    <tab>
		\v    <vertical	tab>

		A backslash followed by	any other character maps to that char-
		acter.

     c-c	Represents the range of	characters between the range end-
		points,	inclusively.

     [:class:]	Represents all characters belonging to the defined character
		class.	Class names are:

		alnum	  <alphanumeric	characters>
		alpha	  <alphabetic characters>
		cntrl	  <control characters>
		digit	  <numeric characters>
		graph	  <graphic characters>
		lower	  <lower-case alphabetic characters>
		print	  <printable characters>
		punct	  <punctuation characters>
		space	  <space characters>
		upper	  <upper-case characters>
		xdigit	  <hexadecimal characters>

		With the exception of the ``upper'' and	``lower'' classes,
		characters in the classes are in unspecified order.  In	the
		``upper'' and ``lower''	classes, characters are	entered	in
		ascending order.

		For specific information as to which ASCII characters are
		included in these classes, see ctype(3)	and related manual
		pages.

     [=equiv=]	Represents all characters belonging to the same	equivalence
		class as equiv,	ordered	by their encoded values.

     [#*n]	Represents n repeated occurrences of the character represented
		by #.  This expression is only valid when it occurs in
		string2.  If n is omitted or is	zero, it is be interpreted as
		large enough to	extend string2 sequence	to the length of
		string1.  If n has a leading zero, it is interpreted as	an
		octal value, otherwise,	it's interpreted as a decimal value.

ENVIRONMENT
     The LANG, LC_ALL, LC_CTYPE	and LC_COLLATE environment variables affect
     the execution of tr as described in environ(7).

DIAGNOSTICS
     The tr utility exits 0 on success,	and >0 if an error occurs.

EXAMPLES
     The following examples are	shown as given to the shell:

     Create a list of the words	in file1, one per line,	where a	word is	taken
     to	be a maximal string of letters.

	   tr -cs "[:alpha:]" "\n" < file1

     Translate the contents of file1 to	upper-case.

	   tr "[:lower:]" "[:upper:]" <	file1

     Strip out non-printable characters	from file1.

	   tr -cd "[:print:]" <	file1

     Remove diacritical	marks from all accented	variants of the	letter `e':

	   tr "[=e=]" "e"

COMPATIBILITY
     System V has historically implemented character ranges using the syntax
     ``[c-c]'' instead of the ``c-c'' used by historic BSD implementations and
     standardized by POSIX.  System V shell scripts should work	under this
     implementation as long as the range is intended to	map in another range,
     i.e. the command ``tr [a-z] [A-Z]'' will work as it will map the ``[''
     character in string1 to the ``['' character in string2.  However, if the
     shell script is deleting or squeezing characters as in the	command	``tr
     -d	[a-z]'', the characters	``['' and ``]''	will be	included in the	dele-
     tion or compression list which would not have happened under an historic
     System V implementation.  Additionally, any scripts that depended on the
     sequence ``a-z'' to represent the three characters	``a'', ``-'' and ``z''
     will have to be rewritten as ``a\-z''.

     The tr utility has	historically not permitted the manipulation of NUL
     bytes in its input	and, additionally, stripped NUL's from its input
     stream.  This implementation has removed this behavior as a bug.

     The tr utility has	historically been extremely forgiving of syntax
     errors, for example, the -c and -s	options	were ignored unless two
     strings were specified.  This implementation will not permit illegal syn-
     tax.

STANDARDS
     The tr utility is expected	to be IEEE Std 1003.2 (``POSIX.2'') compati-
     ble.  It should be	noted that the feature wherein the last	character of
     string2 is	duplicated if string2 has less characters than string1 is per-
     mitted by POSIX but is not	required.  Shell scripts attempting to be por-
     table to other POSIX systems should use the ``[#*]'' convention instead
     of	relying	on this	behavior.  The -u option is an extension to the	IEEE
     Std 1003.2	(``POSIX.2'') standard.

FreeBSD	9.2		       October 11, 1997			   FreeBSD 9.2

NAME | SYNOPSIS | DESCRIPTION | ENVIRONMENT | DIAGNOSTICS | EXAMPLES | COMPATIBILITY | STANDARDS

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