NAME

iso2022, iso-2022, ISO-2022 − A character encoding mechanism standardized by the International Standards Organization (ISO)

DESCRIPTION

The ISO-2022 standard defines a mechanism for handling single-byte and multibyte characters. The standard specifies four classes of character sets:

       •The 94-charset class, which contains character sets with 94 positions (single-byte characters).  Examples are the ASCII and JIS X0201 character sets. 

       •The 96-charset class, which contains character sets with 96 positions (single-byte characters). Examples are the ISO Latin series of character sets. 

       •The 94x94-charset class, which contains character sets with 94x94 positions (2-byte characters). Examples are the GB 2312 and the CNS 11643 character sets. 

       •The 96x96-charset class,  which contains character sets with 96x96 positions (2-byte characters). 

In the ISO-2022 standard, four registers, called G0, G1, G2 and G3, are used to reference a character set. Before a character set can be used, the character set must be assigned, or designated, to one of these registers.  The designation of a character set is done by using an escape sequence in the following format:

ESC [I] F

In this format:

IIs an intermediate character that is used to designate a character set to one of the registers (G0, G1, G2, oR G3). 

FIs a unique final character of a particular character set. 

The designation of a character set, whose final character is F, to different registers is as follows:

ESC $ F
Designates a multibyte character set (94x94 or 96x96) to G0.

ESC ( F
Designates a character set in the 94-charset class to G0.

ESC ) F
Designates a character set in the 94-charset class to G1.

ESC ∗ F
Designates a character set in the 94-charset class to G2.

ESC + F
Designates a character set in the 94-charset class to G3.

ESC - F
Designates a character set in the 96-charset class to G1.

ESC . F
Designates a character set in the 96-charset class to G2.

ESC / F
Designates a character set in the 96-charset class to G3.

SEE ALSO

Commands: locale(1)

Others: ascii(5), i18n_intro(5), iso2022jp(5), l10n_intro(5)