bcd ascii 转换

const unsigned char os_toascii[256] = {
0x00, 0x01, 0x02, 0x03, 0x85, 0x09, 0x86, 0x7f, /* 00-0f: */
0x87, 0x8d, 0x8e, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* ................ */
0x10, 0x11, 0x12, 0x13, 0x8f, 0x0a, 0x08, 0x97, /* 10-1f: */
0x18, 0x19, 0x9c, 0x9d, 0x1c, 0x1d, 0x1e, 0x1f, /* ................ */
0x80, 0x81, 0x82, 0x83, 0x84, 0x92, 0x17, 0x1b, /* 20-2f: */
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x05, 0x06, 0x07, /* ................ */
0x90, 0x91, 0x16, 0x93, 0x94, 0x95, 0x96, 0x04, /* 30-3f: */
0x98, 0x99, 0x9a, 0x9b, 0x14, 0x15, 0x9e, 0x1a, /* ................ */
0x20, 0xa0, 0xe2, 0xe4, 0xe0, 0xe1, 0xe3, 0xe5, /* 40-4f: */
0xe7, 0xf1, 0xa2, 0x2e, 0x3c, 0x28, 0x2b, 0x7c, /* ........... <(+| */
0x26, 0xe9, 0xea, 0xeb, 0xe8, 0xed, 0xee, 0xef, /* 50-5f: */
0xec, 0xdf, 0x21, 0x24, 0x2a, 0x29, 0x3b, 0x5e, /* &.........!$*);^ */
0x2d, 0x2f, 0xc2, 0xc4, 0xc0, 0xc1, 0xc3, 0xc5, /* 60-6f: */
0xc7, 0xd1, 0xa6, 0x2c, 0x25, 0x5f, 0x3e, 0x3f, /* -/.........,%_> ? */
0xf8, 0xc9, 0xca, 0xcb, 0xc8, 0xcd, 0xce, 0xcf, /* 70-7f: */
0xcc, 0x60, 0x3a, 0x23, 0x40, 0x27, 0x3d, 0x22, /* .........`:#@ '= " */
0xd8, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 80-8f: */
0x68, 0x69, 0xab, 0xbb, 0xf0, 0xfd, 0xfe, 0xb1, /* .abcdefghi...... */
0xb0, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, /* 90-9f: */
0x71, 0x72, 0xaa, 0xba, 0xe6, 0xb8, 0xc6, 0xa4, /* .jklmnopqr...... */
0xb5, 0x7e, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, /* a0-af: */
0x79, 0x7a, 0xa1, 0xbf, 0xd0, 0x5b, 0xde, 0xae, /* .~stuvwxyz...[.. */
0xac, 0xa3, 0xa5, 0xb7, 0xa9, 0xa7, 0xb6, 0xbc, /* b0-bf: */
0xbd, 0xbe, 0xdd, 0xa8, 0xaf, 0x5d, 0xb4, 0xd7, /* .............].. */
0x7b, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* c0-cf: */
0x48, 0x49, 0xad, 0xf4, 0xf6, 0xf2, 0xf3, 0xf5, /* {ABCDEFGHI...... */
0x7d, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50, /* d0-df: */
0x51, 0x52, 0xb9, 0xfb, 0xfc, 0xf9, 0xfa, 0xff, /* }JKLMNOPQR...... */
0x5c, 0xf7, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, /* e0-ef: */
0x59, 0x5a, 0xb2, 0xd4, 0xd6, 0xd2, 0xd3, 0xd5, /* \.STUVWXYZ...... */
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* f0-ff: */
0x38, 0x39, 0xb3, 0xdb, 0xdc, 0xd9, 0xda, 0x9f /* 0123456789...... */
};

const unsigned char os_toebcdic[256] = {
0x00, 0x01, 0x02, 0x03, 0x37, 0x2d, 0x2e, 0x2f, /* 00-0f: */
0x16, 0x05, 0x15, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* ................ */
0x10, 0x11, 0x12, 0x13, 0x3c, 0x3d, 0x32, 0x26, /* 10-1f: */
0x18, 0x19, 0x3f, 0x27, 0x1c, 0x1d, 0x1e, 0x1f, /* ................ */
0x40, 0x5a, 0x7f, 0x7b, 0x5b, 0x6c, 0x50, 0x7d, /* 20-2f: */
0x4d, 0x5d, 0x5c, 0x4e, 0x6b, 0x60, 0x4b, 0x61, /* ! "#$%& '()*+,-./ */
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* 30-3f: */
0xf8, 0xf9, 0x7a, 0x5e, 0x4c, 0x7e, 0x6e, 0x6f, /* 0123456789:; <=> ? */
0x7c, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, /* 40-4f: */
0xc8, 0xc9, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, /* @ABCDEFGHIJKLMNO */
0xd7, 0xd8, 0xd9, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, /* 50-5f: */
0xe7, 0xe8, 0xe9, 0xad, 0xe0, 0xbd, 0x5f, 0x6d, /* PQRSTUVWXYZ[\]^_ */
0x79, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 60-6f: */
0x88, 0x89, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, /* `abcdefghijklmno */
0x97, 0x98, 0x99, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, /* 70-7f: */
0xa7, 0xa8, 0xa9, 0xc0, 0x4f, 0xd0, 0xa1, 0x07, /* pqrstuvwxyz{|}~. */
0x20, 0x21, 0x22, 0x23, 0x24, 0x04, 0x06, 0x08, /* 80-8f: */
0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x09, 0x0a, 0x14, /* ................ */
0x30, 0x31, 0x25, 0x33, 0x34, 0x35, 0x36, 0x17, /* 90-9f: */
0x38, 0x39, 0x3a, 0x3b, 0x1a, 0x1b, 0x3e, 0xff, /* ................ */
0x41, 0xaa, 0x4a, 0xb1, 0x9f, 0xb2, 0x6a, 0xb5, /* a0-af: */
0xbb, 0xb4, 0x9a, 0x8a, 0xb0, 0xca, 0xaf, 0xbc, /* ................ */
0x90, 0x8f, 0xea, 0xfa, 0xbe, 0xa0, 0xb6, 0xb3, /* b0-bf: */
0x9d, 0xda, 0x9b, 0x8b, 0xb7, 0xb8, 0xb9, 0xab, /* ................ */
0x64, 0x65, 0x62, 0x66, 0x63, 0x67, 0x9e, 0x68, /* c0-cf: */
0x74, 0x71, 0x72, 0x73, 0x78, 0x75, 0x76, 0x77, /* ................ */
0xac, 0x69, 0xed, 0xee, 0xeb, 0xef, 0xec, 0xbf, /* d0-df: */
0x80, 0xfd, 0xfe, 0xfb, 0xfc, 0xba, 0xae, 0x59, /* ................ */
0x44, 0x45, 0x42, 0x46, 0x43, 0x47, 0x9c, 0x48, /* e0-ef: */
0x54, 0x51, 0x52, 0x53, 0x58, 0x55, 0x56, 0x57, /* ................ */
0x8c, 0x49, 0xcd, 0xce, 0xcb, 0xcf, 0xcc, 0xe1, /* f0-ff: */
0x70, 0xdd, 0xde, 0xdb, 0xdc, 0x8d, 0x8e, 0xdf /* ................ */
};

/* Translate a memory block from EBCDIC (host charset) to ASCII (net charset)
* dest and srce may be identical, or separate memory blocks, but
* should not overlap.
*/
void
ebcdic2ascii(void *dest, const void *srce, size_t count)
{
unsigned char *udest = dest;
const unsigned char *usrce = srce;
while (count-- != 0) {
*udest++ = os_toascii[*usrce++];
}
}

void
ascii2ebcdic(void *dest, const void *srce, size_t count)
{
unsigned char *udest = dest;
const unsigned char *usrce = srce;

while (count-- != 0) {
*udest++ = os_toebcdic[*usrce++];
}
}