• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1IBM OS/400 implements iconv in an odd way:
2- Type iconv_t is a structure: therefore objects of this type cannot be
3  compared to (iconv_t) -1.
4- Supported character sets names are all of the form IBMCCSIDccsid..., where
5  ccsid is a decimal 5-digit integer identifying an IBM coded character set.
6  In addition, character set names have to be given in EBCDIC.
7  Standard character set names like "UTF-8" are NOT recognized.
8- The prototype of iconv_open() does not declare parameters as const, although
9  they are not altered.
10
11 Since libiconv does not support EBCDIC, use of this package here as a
12replacement is not a solution.
13
14 For these reasons, the code in this directory implements a wrapper to the
15OS/400 iconv implementation. The wrapper performs the following transformations:
16- Type iconv_t is an pointer. Although OS/400 pointers are odd, comparing
17  with (iconv_t) -1 is OK.
18- All IANA character set names are recognized in a coding- and case-insensitive
19  way, providing an equivalent CCSID exists. see
20  http://www.iana.org/assignments/character-sets/character-sets.xhtml
21- All CCSIDs from the association file can be expressed as IBMCCSIDxxxxx where
22  xxxxx is the 5 digit CCSID; no null terminator is required. Alternate codes
23  are of the form ibm-xxx (null-terminated), where xxx is the integer CCSID with
24  leading zeroes stripped.
25- If a IANA BIBenum is defined for a CCSID, the name iana-xxx can be used,
26  where xxx is the integer MIBenum without leading zeroes.
27- In addition, some aliases are also taken from the association file. Examples
28  are: ASCII, EBCDIC, UTF8.
29- Prototype of iconv_open() has const parameters.
30- Character code names can be given in any code.
31
32Character set names to CCSID conversion.
33- http://www.iana.org/assignments/character-sets/character-sets.xhtml provides
34  all IANA registered character set names and aliases associated with a
35  MIBenum, that is a unique character set identifier.
36- A hand-maintained file ccsid_mibenum.xml associates IBM CCSIDs to
37  IANA MBenums.
38- An OS/400 C program (in subdirectory bldcsndfa) generates a deterministic
39  finite automaton from the files mentioned above into a C file for all
40  possible character set name and associating each of them with its
41  corresponding CCSID. This program can only be run on OS/400 since it uses
42  the native iconv support for EBCDIC.
43- Since these operations are tedious and the table generation needs bootstraping
44  with libxml2, the generated automaton is stored within sources and need not
45  be rebuilt at each compilation. However, source is provided here to allow
46  new table generation with conversion tables that were not available at the
47  time of original generation.
48