/* cksum -- calculate and print POSIX.2 checksums and sizes of files Copyright (C) 1992, 1995 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Written by Q. Frank Xia, qx@math.columbia.edu. Cosmetic changes and reorganization by David MacKenzie, djm@gnu.ai.mit.edu. Usage: cksum [file...] The code segment between "#ifdef CRCTAB" and "#else" is the code which calculates the "crctab". It is included for those who want verify the correctness of the "crctab". To recreate the "crctab", do following: cc -DCRCTAB -o crctab cksum.c crctab > crctab.h As Bruce Evans pointed out to me, the crctab in the sample C code in 4.9.10 Rationale of P1003.2/D11.2 is represented in reversed order. Namely, 0x01 is represented as 0x80, 0x02 is represented as 0x40, etc. The generating polynomial is crctab[0x80]=0xedb88320 instead of crctab[1]=0x04C11DB7. But the code works only for a non-reverse order crctab. Therefore, the sample implementation is wrong. This software is compatible with neither the System V nor the BSD `sum' program. It is supposed to conform to P1003.2/D11.2, except foreign language interface (4.9.5.3 of P1003.2/D11.2) support. Any inconsistency with the standard except 4.9.5.3 is a bug. */ #include #ifdef CRCTAB #include #define BIT(x) ( (unsigned long)1 << (x) ) #define SBIT BIT(31) /* The generating polynomial is 32 26 23 22 16 12 11 10 8 7 5 4 2 1 G(X)=X + X + X + X + X + X + X + X + X + X + X + X + X + X + 1 The i bit in GEN is set if X^i is a summand of G(X) except X^32. */ #define GEN (BIT(26)|BIT(23)|BIT(22)|BIT(16)|BIT(12)|BIT(11)|BIT(10)\ |BIT(8) |BIT(7) |BIT(5) |BIT(4) |BIT(2) |BIT(1) |BIT(0)); static unsigned long r[8]; static void fill_r () { int i; r[0] = GEN; for (i = 1; i < 8; i++) r[i] = (r[i - 1] & SBIT) ? (r[i - 1] << 1) ^ r[0] : r[i - 1] << 1; } static unsigned long remainder (m) int m; { unsigned long rem = 0; int i; for (i = 0; i < 8; i++) if (BIT (i) & m) rem = rem ^ r[i]; return rem & 0xFFFFFFFF; /* Make it run on 64-bit machine. */ } void main () { int i; fill_r (); printf ("unsigned long crctab[256] = {\n 0x0"); for (i = 0; i < 51; i++) { printf (",\n 0x%08X, 0x%08X, 0x%08X, 0x%08X, 0x%08X", remainder (i * 5 + 1), remainder (i * 5 + 2), remainder (i * 5 + 3), remainder (i * 5 + 4), remainder (i * 5 + 5)); } printf ("\n};\n"); exit (0); } #else /* !CRCTAB */ #include #include #include #include "system.h" #include "version.h" #include "error.h" /* Number of bytes to read at once. */ #define BUFLEN (1 << 16) /* The name this program was run with. */ char *program_name; /* If nonzero, display usage information and exit. */ static int show_help; /* If nonzero, print the version on standard output then exit. */ static int show_version; static struct option const long_options[] = { {"help", no_argument, &show_help, 1}, {"version", no_argument, &show_version, 1}, {0, 0, 0, 0} }; static unsigned long const crctab[256] = { 0x0, 0x04C11DB7, 0x09823B6E, 0x0D4326D9, 0x130476DC, 0x17C56B6B, 0x1A864DB2, 0x1E475005, 0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6, 0x2B4BCB61, 0x350C9B64, 0x31CD86D3, 0x3C8EA00A, 0x384FBDBD, 0x4C11DB70, 0x48D0C6C7, 0x4593E01E, 0x4152FDA9, 0x5F15ADAC, 0x5BD4B01B, 0x569796C2, 0x52568B75, 0x6A1936C8, 0x6ED82B7F, 0x639B0DA6, 0x675A1011, 0x791D4014, 0x7DDC5DA3, 0x709F7B7A, 0x745E66CD, 0x9823B6E0, 0x9CE2AB57, 0x91A18D8E, 0x95609039, 0x8B27C03C, 0x8FE6DD8B, 0x82A5FB52, 0x8664E6E5, 0xBE2B5B58, 0xBAEA46EF, 0xB7A96036, 0xB3687D81, 0xAD2F2D84, 0xA9EE3033, 0xA4AD16EA, 0xA06C0B5D, 0xD4326D90, 0xD0F37027, 0xDDB056FE, 0xD9714B49, 0xC7361B4C, 0xC3F706FB, 0xCEB42022, 0xCA753D95, 0xF23A8028, 0xF6FB9D9F, 0xFBB8BB46, 0xFF79A6F1, 0xE13EF6F4, 0xE5FFEB43, 0xE8BCCD9A, 0xEC7DD02D, 0x34867077, 0x30476DC0, 0x3D044B19, 0x39C556AE, 0x278206AB, 0x23431B1C, 0x2E003DC5, 0x2AC12072, 0x128E9DCF, 0x164F8078, 0x1B0CA6A1, 0x1FCDBB16, 0x018AEB13, 0x054BF6A4, 0x0808D07D, 0x0CC9CDCA, 0x7897AB07, 0x7C56B6B0, 0x71159069, 0x75D48DDE, 0x6B93DDDB, 0x6F52C06C, 0x6211E6B5, 0x66D0FB02, 0x5E9F46BF, 0x5A5E5B08, 0x571D7DD1, 0x53DC6066, 0x4D9B3063, 0x495A2DD4, 0x44190B0D, 0x40D816BA, 0xACA5C697, 0xA864DB20, 0xA527FDF9, 0xA1E6E04E, 0xBFA1B04B, 0xBB60ADFC, 0xB6238B25, 0xB2E29692, 0x8AAD2B2F, 0x8E6C3698, 0x832F1041, 0x87EE0DF6, 0x99A95DF3, 0x9D684044, 0x902B669D, 0x94EA7B2A, 0xE0B41DE7, 0xE4750050, 0xE9362689, 0xEDF73B3E, 0xF3B06B3B, 0xF771768C, 0xFA325055, 0xFEF34DE2, 0xC6BCF05F, 0xC27DEDE8, 0xCF3ECB31, 0xCBFFD686, 0xD5B88683, 0xD1799B34, 0xDC3ABDED, 0xD8FBA05A, 0x690CE0EE, 0x6DCDFD59, 0x608EDB80, 0x644FC637, 0x7A089632, 0x7EC98B85, 0x738AAD5C, 0x774BB0EB, 0x4F040D56, 0x4BC510E1, 0x46863638, 0x42472B8F, 0x5C007B8A, 0x58C1663D, 0x558240E4, 0x51435D53, 0x251D3B9E, 0x21DC2629, 0x2C9F00F0, 0x285E1D47, 0x36194D42, 0x32D850F5, 0x3F9B762C, 0x3B5A6B9B, 0x0315D626, 0x07D4CB91, 0x0A97ED48, 0x0E56F0FF, 0x1011A0FA, 0x14D0BD4D, 0x19939B94, 0x1D528623, 0xF12F560E, 0xF5EE4BB9, 0xF8AD6D60, 0xFC6C70D7, 0xE22B20D2, 0xE6EA3D65, 0xEBA91BBC, 0xEF68060B, 0xD727BBB6, 0xD3E6A601, 0xDEA580D8, 0xDA649D6F, 0xC423CD6A, 0xC0E2D0DD, 0xCDA1F604, 0xC960EBB3, 0xBD3E8D7E, 0xB9FF90C9, 0xB4BCB610, 0xB07DABA7, 0xAE3AFBA2, 0xAAFBE615, 0xA7B8C0CC, 0xA379DD7B, 0x9B3660C6, 0x9FF77D71, 0x92B45BA8, 0x9675461F, 0x8832161A, 0x8CF30BAD, 0x81B02D74, 0x857130C3, 0x5D8A9099, 0x594B8D2E, 0x5408ABF7, 0x50C9B640, 0x4E8EE645, 0x4A4FFBF2, 0x470CDD2B, 0x43CDC09C, 0x7B827D21, 0x7F436096, 0x7200464F, 0x76C15BF8, 0x68860BFD, 0x6C47164A, 0x61043093, 0x65C52D24, 0x119B4BE9, 0x155A565E, 0x18197087, 0x1CD86D30, 0x029F3D35, 0x065E2082, 0x0B1D065B, 0x0FDC1BEC, 0x3793A651, 0x3352BBE6, 0x3E119D3F, 0x3AD08088, 0x2497D08D, 0x2056CD3A, 0x2D15EBE3, 0x29D4F654, 0xC5A92679, 0xC1683BCE, 0xCC2B1D17, 0xC8EA00A0, 0xD6AD50A5, 0xD26C4D12, 0xDF2F6BCB, 0xDBEE767C, 0xE3A1CBC1, 0xE760D676, 0xEA23F0AF, 0xEEE2ED18, 0xF0A5BD1D, 0xF464A0AA, 0xF9278673, 0xFDE69BC4, 0x89B8FD09, 0x8D79E0BE, 0x803AC667, 0x84FBDBD0, 0x9ABC8BD5, 0x9E7D9662, 0x933EB0BB, 0x97FFAD0C, 0xAFB010B1, 0xAB710D06, 0xA6322BDF, 0xA2F33668, 0xBCB4666D, 0xB8757BDA, 0xB5365D03, 0xB1F740B4 }; /* Nonzero if any of the files read were the standard input. */ static int have_read_stdin; /* Calculate and print the checksum and length in bytes of file FILE, or of the standard input if FILE is "-". If PRINT_NAME is nonzero, print FILE next to the checksum and size. Return 0 if successful, -1 if an error occurs. */ static int cksum (char *file, int print_name) { unsigned char buf[BUFLEN]; unsigned long crc = 0; long length = 0; long bytes_read; register FILE *fp; if (!strcmp (file, "-")) { fp = stdin; have_read_stdin = 1; } else { fp = fopen (file, "r"); if (fp == NULL) { error (0, errno, "%s", file); return -1; } } while ((bytes_read = fread (buf, 1, BUFLEN, fp)) > 0) { unsigned char *cp = buf; length += bytes_read; while (bytes_read--) crc = (crc << 8) ^ crctab[((crc >> 24) ^ *(cp++)) & 0xFF]; } if (ferror (fp)) { error (0, errno, "%s", file); if (strcmp (file, "-")) fclose (fp); return -1; } if (strcmp (file, "-") && fclose (fp) == EOF) { error (0, errno, "%s", file); return -1; } bytes_read = length; while (bytes_read > 0) { crc = (crc << 8) ^ crctab[((crc >> 24) ^ bytes_read) & 0xFF]; bytes_read >>= 8; } crc = ~crc & 0xFFFFFFFF; printf ("%10lu %8ld", crc, length); if (print_name) printf (" %s", file); putchar ('\n'); return 0; } static void usage (int status) { if (status != 0) fprintf (stderr, _("Try `%s --help' for more information.\n"), program_name); else { printf (_("\ Usage: %s [OPTION]... [FILE]...\n\ "), program_name); printf (_("\ Print CRC checksum and byte counts of each FILE.\n\ \n\ --help display this help and exit\n\ --version output version information and exit\n\ ")); } exit (status); } void main (int argc, char **argv) { int i, c; int errors = 0; program_name = argv[0]; have_read_stdin = 0; while ((c = getopt_long (argc, argv, "", long_options, (int *) 0)) != EOF) { switch (c) { case 0: break; default: usage (1); } } if (show_version) { printf ("cksum - %s\n", version_string); exit (0); } if (show_help) usage (0); if (optind >= argc) { if (cksum ("-", 0) < 0) errors = 1; } else { for (i = optind; i < argc; i++) if (cksum (argv[i], 1) < 0) errors = 1; } if (have_read_stdin && fclose (stdin) == EOF) error (1, errno, "-"); exit (errors); } #endif /* !CRCTAB */