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| -rw-r--r-- | norm_charmap.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/norm_charmap.c b/norm_charmap.c new file mode 100644 index 00000000..30204871 --- /dev/null +++ b/norm_charmap.c @@ -0,0 +1,144 @@ +/* + * The Single Unix Specification function nl_langinfo(CODESET) + * returns the name of the encoding used by the currently selected + * locale: + * + * http://www.opengroup.org/onlinepubs/7908799/xsh/langinfo.h.html + * + * Unfortunately the encoding names are not yet standardized. + * This function knows about the encoding names used on many + * different systems and converts them where possible into + * the corresponding MIME charset name registered in + * + * http://www.iana.org/assignments/character-sets + * + * Please extend it as needed and suggest improvements to the author. + * + * Markus.Kuhn@cl.cam.ac.uk -- 2002-03-11 + * Permission to use, copy, modify, and distribute this software + * for any purpose and without fee is hereby granted. The author + * disclaims all warranties with regard to this software. + * + * Latest version: + * + * http://www.cl.cam.ac.uk/~mgk25/ucs/norm_charmap.c + */ + +#include <string.h> + +#ifdef TEST +#include <stdio.h> +#include <locale.h> +#include <langinfo.h> +#endif + +#define digit(x) ((x) >= '0' && (x) <= '9') + +static char buf[16]; + +char *norm_charmap(char *name) +{ + char *p; + + if (!name) + return name; + + /* Many need no remapping, but they are listed here so you + * can see what output to expect, and modify for your needs + * as necessary. */ + if (!strcmp(name, "UTF-8")) + return "UTF-8"; + if (!strcmp(name, "EUC-JP")) + return "EUC-JP"; + if (!strcmp(name, "EUC-KR")) + return "EUC-KR"; + if (!strcmp(name, "EUC-TW")) + return "EUC-TW"; + if (!strcmp(name, "KOI8-R")) + return "KOI8-R"; + if (!strcmp(name, "KOI8-U")) + return "KOI8-U"; + if (!strcmp(name, "GBK")) + return "GBK"; + if (!strcmp(name, "GB2312")) + return "GB2312"; + if (!strcmp(name, "GB18030")) + return "GB18030"; + if (!strcmp(name, "VSCII")) + return "VSCII"; + + /* ASCII comes in many names */ + if (!strcmp(name, "ASCII") || + !strcmp(name, "US-ASCII") || + !strcmp(name, "ANSI_X3.4-1968") || + !strcmp(name, "646") || + !strcmp(name, "ISO646") || + !strcmp(name, "ISO_646.IRV")) + return "US-ASCII"; + + /* ISO 8859 will be converted to "ISO-8859-x" */ + if ((p = strstr(name, "8859-"))) { + memcpy(buf, "ISO-8859-\0\0", 12); + p += 5; + if (digit(*p)) { + buf[9] = *p++; + if (digit(*p)) buf[10] = *p++; + return buf; + } + } + + /* Windows code pages will be converted to "WINDOWS-12xx" */ + if ((p = strstr(name, "CP12"))) { + memcpy(buf, "WINDOWS-12\0\0", 13); + p += 4; + if (digit(*p)) { + buf[10] = *p++; + if (digit(*p)) buf[11] = *p++; + return buf; + } + } + + /* TIS-620 comes in at least the following two forms */ + if (!strcmp(name, "TIS-620") || + !strcmp(name, "TIS620.2533")) + return "ISO-8859-11"; + + /* For some, uppercase/lowercase might differ */ + if (!strcmp(name, "Big5") || !strcmp(name, "BIG5")) + return "Big5"; + if (!strcmp(name, "Big5HKSCS") || !strcmp(name, "BIG5HKSCS")) + return "Big5HKSCS"; + + /* I don't know of any implementation of nl_langinfo(CODESET) out + * there that returns anything else (and I'm not even certain all of + * the above occur in the wild), but just in case, as a fallback, + * return the unmodified name. */ +#ifdef TEST + printf("**** Unknown encoding name '%s'!\n", name); +#endif + return name; +} + +/* For a demo, compile with + * + * gcc -W -Wall -o norm_charmap -D TEST norm_charmap.c + * + * and then test it on all available locales with + * + * for i in `locale -a` ; do printf "$i: " ; LC_ALL=$i ./norm_charmap ; done + */ + +#ifdef TEST +int main(int argc, char **argv) +{ + char *s; + if (argc > 1) + s = argv[1]; + else { + setlocale(LC_CTYPE, ""); + s = nl_langinfo(CODESET); + } + printf("%s -> %s\n", s, norm_charmap(s)); + return 0; +} +#endif |