eucset(1)eucset(1)NAMEeucset - Sets and gets EUC code widths for the terminal
SYNOPSISeucset [cswidth]
eucset-p
OPTIONS
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 ter‐
minal. 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 simultaneously.
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 characteris‐
tics.
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
specification.
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. Charac‐
ters 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 dis‐
play column. The eucset command must be used to set the characteris‐
tics 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 dis‐
play characters in this class. X2 is the number of bytes required to
encode a character 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 des‐
ignates 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
Your standard input is not an interactive terminal. The maximum char‐
acter width of 8 was exceeded.
EXAMPLES
To display the encoding and display widths for the EUC code set classes
1-3 in your environment, enter: eucset-p To change the current set‐
tings 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)eucset(1)