The CHARMAP section

The CHARMAP section defines the values for the symbolic names representing characters in the coded character set. Each charmap file must define at least the portable character set. The character symbolic names or alternate symbolic names (or both) must be used to define the portable character set. These are shown in Table 1.

Additional characters can be defined by the user with symbolic character names.

The CHARMAP section starts with the line containing the keyword CHARMAP, and ends with the line containing the keywords END CHARMAP. CHARMAP and END CHARMAP must both start in column one.

The character set mapping definitions are all the lines between the first and last lines of the CHARMAP section. The formats of the character set mappings for this section are as follows:

"%s %s %s\n", <symbolic-name>, <encoding>, <comments>
"%s…%s %s %s\n", <symbolic-name>, <symbolic-name>, <encoding>, <comments>

The first format defines a single symbolic name and a corresponding encoding. A symbolic name is one or more characters with visible glyphs, enclosed between angle brackets.

For reasons of portability, a symbolic name should include only the characters from the invariant part of the portable character set. If you use variant characters or decimal or hexadecimal notation in a symbolic name, the symbolic name will not be portable. A character following an escape character is interpreted as itself; for example, the sequence <\\\>> represents the symbolic name \> enclosed within angle brackets, where the backslash \ is the escape character. If / is the escape character, the sequence <///>> represents the symbolic name />. In the supplied charmap files, the escape character has been redefined to the forward slash /.

The second format defines a group of symbolic names associated with a range of values. The two symbolic names are comprised of two parts, a prefix and suffix. The prefix consists of zero or more non-numeric invariant visible glyph characters and is the same for both symbolic names. The suffix consists of a positive decimal integer. The suffix of the first symbolic name must be less than or equal to the suffix of the second symbolic name. As an example, <j0101>...<j0104> is interpreted as the symbolic names <j0101>,<j0102>,<j0103>,<j0104>. The common prefix is 'j' and the suffixes are '0101' and '0104'.

The encoding part can be written in one of two forms:

  <escape-char><number>                       (single byte value)
  <escape-char><number><escape-char><number>  (double byte value)

The number can be written using octal, decimal, or hexadecimal notation. Decimal numbers are written as a 'd' followed by 2 or 3 decimal digits. Hexadecimal numbers are written as an 'x' followed by 2 hexadecimal digits. An octal number is written with 2 or 3 octal digits. As an example, the single byte value x1F could be written as '\37', '\x1F', or '\d31'.

The double byte value of 0x1A1F could be written as '\32\37', '\x1A\x1F', or '\d26\d31'.

In lines defining ranges of symbolic names, the encoded value is the value for the first symbolic name in the range (the symbolic name preceding the ellipsis). Subsequent names defined by the range have encoding values in increasing order.

When constants are concatenated for multibyte character values, they must be of the same type, and are interpreted in byte order from first to last with the least significant byte of the multibyte character specified by the last constant. Each value is then prepended by the byte value of <shift_out> and appended with the byte value of <shift_in>. Such a string represents one EBCDIC multibyte character, as the following example shows:

<escape_char>   /
<comment_char>  %
<mb_cur_max>    4
<mb_cur_min>    1
<shift-out>     /x0e
<shift-in>      /x0f
CHARMAP
% many definition lines
<j0101>…<j0104>            /d129/d254
%many definition lines
END CHARMAP

is interpreted as:

<j0101>                      /d129/d254
<j0102>                      /d129/d255
<j0103>                      /d130/d0
<j0104>                      /d130/d1

It produces four 4-byte long multibyte EBCDIC characters:

<j0101>                  x0Ex81xFEx0F
<j0102>                  x0Ex81xFFx0F
<j0103>                  x0Ex82x00x0F
<j0104>                  x0Ex82x01x0F