/* * compaction.c */ #include <sys/types.h> #include <netinet/in.h> char uncompact_table[7][16] = { 0, ' ', '\n', 'a', 'e', 'h', 'i', 'n', 'o', 's', 't', 1, 2, 3, 4, 5, 'b', 'c', 'd', 'f', 'g', 'j', 'k', 'l', 'm', 'p', 'q', 'r', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '!', '"', '#', '@', '~', '&', 39, '(', ')', '*', '+', ',', '-', '.', '/', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ':', ';', '<', '=', '>', '?', '[', '\\', ']', '^', 6, '`', '_', '{', '|', '}', '%', '$', -1, 0, 0, 0, 0, 0, 0, 0, 0}; char compact_table[128] = { 1, 60, 61, 62, 102, 101, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 63, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 91, 92, 93, 94, 97, 96, 3, 16, 17, 18, 4, 19, 20, 5, 6, 21, 22, 23, 24, 7, 8, 25, 26, 27, 9, 10, 28, 29, 30, 31, 32, 33, 98, 99, 100, 64 }; /* stores a nibble */ char *store_nibble(char *dest, int n) { static int toggle = 0; if (toggle) { *dest++ |= (char) n; toggle = 0; } else { if (!n) { *dest = 0; dest++; return dest; } n <<= 4; *dest = (char) n; toggle = 1; } return dest; } /* retrieves a nibble */ char *get_nibble(int *n, char *source) { static int toggle = 0; if (toggle) { *n = ((int) *source++) & 15; toggle = 0; } else { *n = (((int) *source) >> 4) & 15; if (!*n) source++; else toggle = 1; } return source; } /* returns new source */ char *get_string(char *dest, char *source) { char c = 1; int n = 0, table = 0; for (; c; table = 0) { c = 1; while (c && c < 7) { source = get_nibble(&n, source); c = uncompact_table[table][n]; if (c && c < 7) table = (int) c; } *dest++ = c; } return source; } /* returns new destination */ char *store_string(dest, source) char *dest, *source; { int n, row, tmp = 1; for (; tmp; source++) { tmp = (int) *source; switch (tmp) { case 0: row = 0; n = 0; break; case '\n': row = 0; n = 2; break; case -1: row = 6; n = 7; break; default: row = (compact_table[tmp - 32]) >> 4; n = (compact_table[tmp - 32]) & 15; break; } switch (row) { case 0: dest = store_nibble(dest, n); break; case 1: dest = store_nibble(dest, 11); dest = store_nibble(dest, n); break; case 2: dest = store_nibble(dest, 12); dest = store_nibble(dest, n); break; case 3: dest = store_nibble(dest, 13); dest = store_nibble(dest, n); break; case 4: dest = store_nibble(dest, 14); dest = store_nibble(dest, n); break; case 5: dest = store_nibble(dest, 15); dest = store_nibble(dest, n); break; case 6: dest = store_nibble(dest, 15); dest = store_nibble(dest, 15); dest = store_nibble(dest, n); break; } } return dest; } /* store 2-byte word in player file */ char *store_word(dest, source) char *dest; int source; { *dest++ = (source >> 8) & 255; *dest++ = source & 255; return dest; } /* store 4-byte word in player file */ char *store_int(dest, source) char *dest; int source; { int i; union { char c[4]; int i; } u; u.i = htonl(source); for (i = 0; i < 4; i++) *dest++ = u.c[i]; return dest; } /* retrieve 2-byte word from player file */ char *get_word(dest, source) char *source; int *dest; { union { char c[4]; int i; } u; u.i = 0; u.c[3] = *source++; u.c[4] = *source++; *dest = ntohl(u.i); return source; } /* retrieve 4-byte int from player file */ char *get_int(dest, source) char *source; int *dest; { int i; union { char c[4]; int i; } u; for (i = 0; i < 4; i++) u.c[i] = *source++; *dest = ntohl(u.i); return source; }