NLS file format memo

nls.txt

svn://svn.reactos.org/reactos/trunk/reactos/tools/create_nls/

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Nls

format of NLS file such as C:\Windows\System32\C_932.NLS

================================================================================
  NLS CODEPAGE (C_XXX.NLS)
================================================================================
                +---------------------------------------------------------------
        HEADER  | WORD      wSize  size in word (0x0D)
                | WORD      CodePage
                | WORD      MaxCharSize
                | BYTE[2]   DefaultChar
                | WORD      UnicodeDefaultChar
                | WORD      unknown1  (maybe Unicode char of DefaultChar)
                | WORD      unknown2  (maybe CodePage char of UnicodeDefaultChar)
                | BYTE[12]  LeadByte
                +---------------------------------------------------------------
   MB2WC TABLE  | WORD      offset of Unicode to CP table in word
                | WORD[256] primary CP to Unicode table
                | WORD      OEM glyph table size in words
                | WORD[size] OEM to Unicode table
                | WORD      Number of DBCS LeadByte range
                | if range != 0:
                |   WORD[256] offsets
                |   WORD[num_of_leadbyte][256] sub table
                +---------------------------------------------------------------
   WC2MB TABLE  | WORD      Unknown (It seems 0x0000 for MaxCharSize==1, 0x0004 for MaxCharSize==2)
                | BYTE[65536] or WORD[65536] (depends on MaxCharSize) Unicode To CP table
                +---------------------------------------------------------------
================================================================================

nlsdump.c

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>

typedef struct {
    WORD wSize; /* in words 0x000D */
    WORD CodePage;
    WORD MaxCharSize; /* 1 or 2 */
    BYTE DefaultChar[MAX_DEFAULTCHAR];
    WCHAR UnicodeDefaultChar;
    WCHAR unknown1;
    WCHAR unknown2;
    BYTE LeadByte[MAX_LEADBYTES];
} NLS_FILE_HEADER;

static size_t
fsize(FILE *f)
{
    size_t p;
    size_t s;

    p = ftell(f);
    fseek(f, 0, SEEK_END);
    s = ftell(f);
    fseek(f, p, SEEK_SET);
    return s;
}

static void *
readfile(char *path, size_t *psize)
{
    FILE *f = fopen(path, "rb");
    size_t s = fsize(f);
    void *p = malloc(s);
    fread(p, 1, s, f);
    fclose(f);
    *psize = s;
    return p;
}

static void
writefile(char *path, void *data, size_t size)
{
    FILE *f = fopen(path, "wb");
    fwrite(data, 1, size, f);
    fclose(f);
}

int main(int argc, char **argv)
{
    size_t s;
    WORD *base;

    base = readfile(argv[1], &s);

    NLS_FILE_HEADER *nls = (NLS_FILE_HEADER *)&base[0];
    printf("Size = %d\n", nls->wSize);
    printf("CodePage = %d\n", nls->CodePage);
    printf("MaxCharSize = %d\n", nls->MaxCharSize);
    printf("DefaultChar = %02x%02x\n", nls->DefaultChar[1], nls->DefaultChar[0]);
    printf("UnicodeDefaultChar = %04x\n", nls->UnicodeDefaultChar);
    printf("unknown1 = %04x\n", nls->unknown1);
    printf("unknown1 = %04x\n", nls->unknown2);
    printf("LeadByte = %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n", nls->LeadByte[0], nls->LeadByte[1], nls->LeadByte[2], nls->LeadByte[3], nls->LeadByte[4], nls->LeadByte[5], nls->LeadByte[6], nls->LeadByte[7], nls->LeadByte[8], nls->LeadByte[9], nls->LeadByte[10], nls->LeadByte[11]);

    WORD *cp_to_wc_table_size = base + nls->wSize;
    WORD *cp_to_wc_table_base = base + nls->wSize + 1;

    printf("offset of Unicode To CP table in words = %d\n", *cp_to_wc_table_size);

    WORD *primary_table_base = cp_to_wc_table_base;
    printf("primary table\n");
    for (int i = 0; i < 256; ++i)
        printf("0x%02x => U+%04x\n", i, primary_table_base[i]);

    WORD *oem_table_size = primary_table_base + 256;
    WORD *oem_table_base = primary_table_base + 256 + 1;
    printf("oem size = %d\n", *oem_table_size);
    for (int i = 0; i < *oem_table_size; ++i)
        printf("oem[0x%02x] => U+%04x\n", i, oem_table_base[i]);

    WORD *num_of_dbcs_leadbyte_range = oem_table_base + *oem_table_size;
    WORD *dbcs_table_base = oem_table_base + *oem_table_size + 1;
    WORD *dbcs_leadbyte_offs = dbcs_table_base;

    WORD num_of_dbcs_leadbyte = 0;
    if (*num_of_dbcs_leadbyte_range != 0) {
        for (int i = 0; i < 256; ++i) {
            if (dbcs_leadbyte_offs[i] != 0)
                num_of_dbcs_leadbyte++;
        }
    }

    WORD dbcs_table_size = 0;
    if (*num_of_dbcs_leadbyte_range != 0)
        dbcs_table_size = 256 + 256 * num_of_dbcs_leadbyte;

    printf("num_of_dbcs_leadbyte_range = %d\n", *num_of_dbcs_leadbyte_range);
    printf("num_of_dbcs_leadbyte = %d\n", num_of_dbcs_leadbyte);

    if (*num_of_dbcs_leadbyte_range != 0) {
        for (int i = 0; i < 256; ++i)
            printf("off[%d] = %d\n", i, dbcs_leadbyte_offs[i]);
        for (int i = 0; i < 256; ++i) {
            if (dbcs_leadbyte_offs[i] == 0)
                continue;
            for (int j = 0; j < 256; ++j)
                printf("0x%02x%02x => U+%04x\n", i, j, dbcs_table_base[dbcs_leadbyte_offs[i] + j]);
        }
    }

    WORD *p_unknown = cp_to_wc_table_base + *cp_to_wc_table_base;
    printf("p_unknown = %04x\n", *p_unknown);

    WORD *wc_to_cp_table_base2 = cp_to_wc_table_base + *cp_to_wc_table_size + 1;
    BYTE *wc_to_cp_table_base1 = (BYTE *)wc_to_cp_table_base2;

    for (int i = 0; i < 65536; ++i) {
        if (nls->MaxCharSize == 1)
            printf("U+%04x => 0x%02x\n", i, wc_to_cp_table_base1[i]);
        else
            printf("U+%04x => 0x%04x\n", i, wc_to_cp_table_base2[i]);
    }

    return 0;
}