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eucset(1)							    eucset(1)



NAME

  eucset - Sets	and gets EUC code widths for the terminal

SYNOPSIS

  eucset [cswidth]

  eucset -p

OPTIONS

  -p  Displays the current settings of the EUC character widths	for the	ter-
      minal

DESCRIPTION

  The eucset command sets or gets the encoding and display widths of the
  Extended UNIX	Code (EUC) characters processed	by the current input termi-
  nal. EUC is an encoding method for code sets composed	of single or multiple
  bytes. It permits applications and the terminal hardware to use the 7-bit
  US ASCII code	and up to three	single-	or multibyte code sets simultane-
  ously.

  If you use the eucset	command	to set EUC character widths, but do not
  specify the cswidth argument,	7-bit U.S. ASCII is applied as a default code
  set. You must	use the	command	to specify any other EUC code sets, whether
  they are single-byte or multibyte.

  EUC Code Set Classes


  EUC divides code sets	into four classes. Each	code set class has two
  characteristics: the number of bytes for encoding the	characters in the
  class, and the number	of display columns to display the characters in	the
  class.  All characters within	a class	possess	the same characteristics.

  Class	0 consists of all 7-bit, single-byte ASCII characters.	The most-
  significant bit of each of these characters is 0 (zero).  Characters in
  class	0 require one byte for encoding, and occupy one	display	column.
  These	values are fixed for class 0 (zero). The 7-bit US ASCII	code is	the
  primary EUC code set,	which is available to users without direct specifica-
  tion.

  A class 1 code set is	a supplementary	EUC code set. Class 1 characters have
  an initial byte whose	most-significant bit is	1.  If character classes 2 or
  3 are	to be used, this initial byte must not be the SS2 or SS3 character,
  as these designate character classes 2 and 3.	 Characters in class 1 may
  require more than 1 byte for encoding, and may require more than 1 display
  column.  The eucset command must be used to set the characteristics for
  code set class 1.


  Class	2 and 3	code sets are supplementary EUC	code sets. Characters in
  these	classes	have an	initial	byte of	SS2 or SS3, respectively.  They
  require more than 1 byte for encoding, and may require more than 1 display
  column.  The eucset command must be used to set the characteristics for
  code set classes 2 and 3.

  The cswidth argument in the eucset command line is a character string	that
  describes the	character widths for code set classes 1	through	3.  The
  string is of the following format:

  X1[:Y1], X2[:Y2], X3[:Y3]

  The value X1 is the number of	bytes required to encode a character in	code
  set class 1.	Y1 is the number of display columns needed to display charac-
  ters in this class.  X2 is the number	of bytes required to encode a charac-
  ter in code set class	2, not counting	the SS2	byte, and Y2 is	the number of
  display columns for code set class 2 characters.  X3 is the number of	bytes
  needed to encode characters in code set class	3, not counting	the SS3	byte,
  and Y3 is the	number of display columns required for these characters. The
  values for the column	widths can be omitted if they are equal	to the number
  of encoding bytes. If	the encoding value of any of the EUC code sets is set
  to 0 (zero), this indicates that the code set	does not exist.

  If no	cswidth	argument is supplied, the eucset command uses the value	of
  the CSWIDTH environment variable. If this variable is	not present, the
  default string 1:1,0:0,0:0 is	substituted. This default string designates
  that the environment uses a single-byte EUC code set that has	characters in
  the EUC code set class 1 format. If the environment uses a multibyte EUC
  code set in the code set class 1 format, single- or multibyte	EUC code sets
  in the code set class	2 or 3 format, or both,	the default setting cannot be
  used.

DIAGNOSTICS

  not a	tty
      Your standard input is not an interactive	terminal.

  ioctl	error
      The maximum character width of 8 was exceeded.

EXAMPLES

   1.  To display the encoding and display widths for the EUC code set
       classes 1-3 in your environment,	enter:
	    eucset -p

   2.  To change the current settings of the encoding and display widths for
       the EUC characters in code set classes 1	and 2 to 2 bytes each, enter:
	    eucset 2:2,2:2,0:0

       or
	    eucset 2,2,0



SEE ALSO

  Interfaces:  eucioctl(7)