src/cksum.c

   1 /* cksum -- calculate and print POSIX.2 checksums and sizes of files
   2    Copyright (C) 1992, 1995 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17 \f
  18 /* Written by Q. Frank Xia, qx@math.columbia.edu.
  19    Cosmetic changes and reorganization by David MacKenzie, djm@gnu.ai.mit.edu.
  20
  21   Usage: cksum [file...]
  22
  23   The code segment between "#ifdef CRCTAB" and "#else" is the code
  24   which calculates the "crctab". It is included for those who want
  25   verify the correctness of the "crctab". To recreate the "crctab",
  26   do following:
  27
  28       cc -DCRCTAB -o crctab cksum.c
  29       crctab > crctab.h
  30
  31   As Bruce Evans pointed out to me, the crctab in the sample C code
  32   in 4.9.10 Rationale of P1003.2/D11.2 is represented in reversed order.
  33   Namely, 0x01 is represented as 0x80, 0x02 is represented as 0x40, etc.
  34   The generating polynomial is crctab[0x80]=0xedb88320 instead of
  35   crctab[1]=0x04C11DB7.  But the code works only for a non-reverse order
  36   crctab.  Therefore, the sample implementation is wrong.
  37
  38   This software is compatible with neither the System V nor the BSD
  39   `sum' program.  It is supposed to conform to P1003.2/D11.2,
  40   except foreign language interface (4.9.5.3 of P1003.2/D11.2) support.
  41   Any inconsistency with the standard except 4.9.5.3 is a bug.  */
  42
  43 #include <config.h>
  44
  45 #ifdef CRCTAB
  46
  47 #include <stdio.h>
  48
  49 #define BIT(x)  ( (unsigned long)1 << (x) )
  50 #define SBIT    BIT(31)
  51
  52 /* The generating polynomial is
  53
  54           32   26   23   22   16   12   11   10   8   7   5   4   2   1
  55     G(X)=X  + X  + X  + X  + X  + X  + X  + X  + X + X + X + X + X + X + 1
  56
  57   The i bit in GEN is set if X^i is a summand of G(X) except X^32.  */
  58
  59 #define GEN     (BIT(26)|BIT(23)|BIT(22)|BIT(16)|BIT(12)|BIT(11)|BIT(10)\
  60                 |BIT(8) |BIT(7) |BIT(5) |BIT(4) |BIT(2) |BIT(1) |BIT(0));
  61
  62 static unsigned long r[8];
  63
  64 static void
  65 fill_r ()
  66 {
  67   int i;
  68
  69   r[0] = GEN;
  70   for (i = 1; i < 8; i++)
  71     r[i] = (r[i - 1] & SBIT) ? (r[i - 1] << 1) ^ r[0] : r[i - 1] << 1;
  72 }
  73
  74 static unsigned long
  75 remainder (m)
  76      int m;
  77 {
  78   unsigned long rem = 0;
  79   int i;
  80
  81   for (i = 0; i < 8; i++)
  82     if (BIT (i) & m)
  83       rem = rem ^ r[i];
  84
  85   return rem & 0xFFFFFFFF;      /* Make it run on 64-bit machine.  */
  86 }
  87
  88 void
  89 main ()
  90 {
  91   int i;
  92
  93   fill_r ();
  94   printf ("unsigned long crctab[256] = {\n  0x0");
  95   for (i = 0; i < 51; i++)
  96     {
  97       printf (",\n  0x%08X, 0x%08X, 0x%08X, 0x%08X, 0x%08X",
  98         remainder (i * 5 + 1), remainder (i * 5 + 2), remainder (i * 5 + 3),
  99               remainder (i * 5 + 4), remainder (i * 5 + 5));
 100     }
 101   printf ("\n};\n");
 102   exit (0);
 103 }
 104
 105 #else /* !CRCTAB */
 106
 107 #include <stdio.h>
 108 #include <getopt.h>
 109 #include <sys/types.h>
 110 #include "system.h"
 111 #include "version.h"
 112 #include "error.h"
 113
 114 /* Number of bytes to read at once.  */
 115 #define BUFLEN (1 << 16)
 116
 117 /* The name this program was run with.  */
 118 char *program_name;
 119
 120 /* If nonzero, display usage information and exit.  */
 121 static int show_help;
 122
 123 /* If nonzero, print the version on standard output then exit.  */
 124 static int show_version;
 125
 126 static struct option const long_options[] =
 127 {
 128   {"help", no_argument, &show_help, 1},
 129   {"version", no_argument, &show_version, 1},
 130   {0, 0, 0, 0}
 131 };
 132
 133 static unsigned long const crctab[256] =
 134 {
 135   0x0,
 136   0x04C11DB7, 0x09823B6E, 0x0D4326D9, 0x130476DC, 0x17C56B6B,
 137   0x1A864DB2, 0x1E475005, 0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6,
 138   0x2B4BCB61, 0x350C9B64, 0x31CD86D3, 0x3C8EA00A, 0x384FBDBD,
 139   0x4C11DB70, 0x48D0C6C7, 0x4593E01E, 0x4152FDA9, 0x5F15ADAC,
 140   0x5BD4B01B, 0x569796C2, 0x52568B75, 0x6A1936C8, 0x6ED82B7F,
 141   0x639B0DA6, 0x675A1011, 0x791D4014, 0x7DDC5DA3, 0x709F7B7A,
 142   0x745E66CD, 0x9823B6E0, 0x9CE2AB57, 0x91A18D8E, 0x95609039,
 143   0x8B27C03C, 0x8FE6DD8B, 0x82A5FB52, 0x8664E6E5, 0xBE2B5B58,
 144   0xBAEA46EF, 0xB7A96036, 0xB3687D81, 0xAD2F2D84, 0xA9EE3033,
 145   0xA4AD16EA, 0xA06C0B5D, 0xD4326D90, 0xD0F37027, 0xDDB056FE,
 146   0xD9714B49, 0xC7361B4C, 0xC3F706FB, 0xCEB42022, 0xCA753D95,
 147   0xF23A8028, 0xF6FB9D9F, 0xFBB8BB46, 0xFF79A6F1, 0xE13EF6F4,
 148   0xE5FFEB43, 0xE8BCCD9A, 0xEC7DD02D, 0x34867077, 0x30476DC0,
 149   0x3D044B19, 0x39C556AE, 0x278206AB, 0x23431B1C, 0x2E003DC5,
 150   0x2AC12072, 0x128E9DCF, 0x164F8078, 0x1B0CA6A1, 0x1FCDBB16,
 151   0x018AEB13, 0x054BF6A4, 0x0808D07D, 0x0CC9CDCA, 0x7897AB07,
 152   0x7C56B6B0, 0x71159069, 0x75D48DDE, 0x6B93DDDB, 0x6F52C06C,
 153   0x6211E6B5, 0x66D0FB02, 0x5E9F46BF, 0x5A5E5B08, 0x571D7DD1,
 154   0x53DC6066, 0x4D9B3063, 0x495A2DD4, 0x44190B0D, 0x40D816BA,
 155   0xACA5C697, 0xA864DB20, 0xA527FDF9, 0xA1E6E04E, 0xBFA1B04B,
 156   0xBB60ADFC, 0xB6238B25, 0xB2E29692, 0x8AAD2B2F, 0x8E6C3698,
 157   0x832F1041, 0x87EE0DF6, 0x99A95DF3, 0x9D684044, 0x902B669D,
 158   0x94EA7B2A, 0xE0B41DE7, 0xE4750050, 0xE9362689, 0xEDF73B3E,
 159   0xF3B06B3B, 0xF771768C, 0xFA325055, 0xFEF34DE2, 0xC6BCF05F,
 160   0xC27DEDE8, 0xCF3ECB31, 0xCBFFD686, 0xD5B88683, 0xD1799B34,
 161   0xDC3ABDED, 0xD8FBA05A, 0x690CE0EE, 0x6DCDFD59, 0x608EDB80,
 162   0x644FC637, 0x7A089632, 0x7EC98B85, 0x738AAD5C, 0x774BB0EB,
 163   0x4F040D56, 0x4BC510E1, 0x46863638, 0x42472B8F, 0x5C007B8A,
 164   0x58C1663D, 0x558240E4, 0x51435D53, 0x251D3B9E, 0x21DC2629,
 165   0x2C9F00F0, 0x285E1D47, 0x36194D42, 0x32D850F5, 0x3F9B762C,
 166   0x3B5A6B9B, 0x0315D626, 0x07D4CB91, 0x0A97ED48, 0x0E56F0FF,
 167   0x1011A0FA, 0x14D0BD4D, 0x19939B94, 0x1D528623, 0xF12F560E,
 168   0xF5EE4BB9, 0xF8AD6D60, 0xFC6C70D7, 0xE22B20D2, 0xE6EA3D65,
 169   0xEBA91BBC, 0xEF68060B, 0xD727BBB6, 0xD3E6A601, 0xDEA580D8,
 170   0xDA649D6F, 0xC423CD6A, 0xC0E2D0DD, 0xCDA1F604, 0xC960EBB3,
 171   0xBD3E8D7E, 0xB9FF90C9, 0xB4BCB610, 0xB07DABA7, 0xAE3AFBA2,
 172   0xAAFBE615, 0xA7B8C0CC, 0xA379DD7B, 0x9B3660C6, 0x9FF77D71,
 173   0x92B45BA8, 0x9675461F, 0x8832161A, 0x8CF30BAD, 0x81B02D74,
 174   0x857130C3, 0x5D8A9099, 0x594B8D2E, 0x5408ABF7, 0x50C9B640,
 175   0x4E8EE645, 0x4A4FFBF2, 0x470CDD2B, 0x43CDC09C, 0x7B827D21,
 176   0x7F436096, 0x7200464F, 0x76C15BF8, 0x68860BFD, 0x6C47164A,
 177   0x61043093, 0x65C52D24, 0x119B4BE9, 0x155A565E, 0x18197087,
 178   0x1CD86D30, 0x029F3D35, 0x065E2082, 0x0B1D065B, 0x0FDC1BEC,
 179   0x3793A651, 0x3352BBE6, 0x3E119D3F, 0x3AD08088, 0x2497D08D,
 180   0x2056CD3A, 0x2D15EBE3, 0x29D4F654, 0xC5A92679, 0xC1683BCE,
 181   0xCC2B1D17, 0xC8EA00A0, 0xD6AD50A5, 0xD26C4D12, 0xDF2F6BCB,
 182   0xDBEE767C, 0xE3A1CBC1, 0xE760D676, 0xEA23F0AF, 0xEEE2ED18,
 183   0xF0A5BD1D, 0xF464A0AA, 0xF9278673, 0xFDE69BC4, 0x89B8FD09,
 184   0x8D79E0BE, 0x803AC667, 0x84FBDBD0, 0x9ABC8BD5, 0x9E7D9662,
 185   0x933EB0BB, 0x97FFAD0C, 0xAFB010B1, 0xAB710D06, 0xA6322BDF,
 186   0xA2F33668, 0xBCB4666D, 0xB8757BDA, 0xB5365D03, 0xB1F740B4
 187 };
 188
 189 /* Nonzero if any of the files read were the standard input. */
 190 static int have_read_stdin;
 191
 192 /* Calculate and print the checksum and length in bytes
 193    of file FILE, or of the standard input if FILE is "-".
 194    If PRINT_NAME is nonzero, print FILE next to the checksum and size.
 195    Return 0 if successful, -1 if an error occurs. */
 196
 197 static int
 198 cksum (char *file, int print_name)
 199 {
 200   unsigned char buf[BUFLEN];
 201   unsigned long crc = 0;
 202   long length = 0;
 203   long bytes_read;
 204   register FILE *fp;
 205
 206   if (!strcmp (file, "-"))
 207     {
 208       fp = stdin;
 209       have_read_stdin = 1;
 210     }
 211   else
 212     {
 213       fp = fopen (file, "r");
 214       if (fp == NULL)
 215         {
 216           error (0, errno, "%s", file);
 217           return -1;
 218         }
 219     }
 220
 221   while ((bytes_read = fread (buf, 1, BUFLEN, fp)) > 0)
 222     {
 223       unsigned char *cp = buf;
 224
 225       length += bytes_read;
 226       while (bytes_read--)
 227         crc = (crc << 8) ^ crctab[((crc >> 24) ^ *(cp++)) & 0xFF];
 228     }
 229
 230   if (ferror (fp))
 231     {
 232       error (0, errno, "%s", file);
 233       if (strcmp (file, "-"))
 234         fclose (fp);
 235       return -1;
 236     }
 237
 238   if (strcmp (file, "-") && fclose (fp) == EOF)
 239     {
 240       error (0, errno, "%s", file);
 241       return -1;
 242     }
 243
 244   bytes_read = length;
 245   while (bytes_read > 0)
 246     {
 247       crc = (crc << 8) ^ crctab[((crc >> 24) ^ bytes_read) & 0xFF];
 248       bytes_read >>= 8;
 249     }
 250
 251   crc = ~crc & 0xFFFFFFFF;
 252
 253   printf ("%10lu %8ld", crc, length);
 254   if (print_name)
 255     printf (" %s", file);
 256   putchar ('\n');
 257
 258   return 0;
 259 }
 260
 261 static void
 262 usage (int status)
 263 {
 264   if (status != 0)
 265     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 266              program_name);
 267   else
 268     {
 269       printf (_("\
 270 Usage: %s [OPTION]... [FILE]...\n\
 271 "),
 272               program_name);
 273       printf (_("\
 274 Print CRC checksum and byte counts of each FILE.\n\
 275 \n\
 276   --help      display this help and exit\n\
 277   --version   output version information and exit\n\
 278 "));
 279     }
 280   exit (status);
 281 }
 282
 283 void
 284 main (int argc, char **argv)
 285 {
 286   int i, c;
 287   int errors = 0;
 288
 289   program_name = argv[0];
 290   setlocale (LC_ALL, "");
 291   bindtextdomain (PACKAGE, LOCALEDIR);
 292   textdomain (PACKAGE);
 293
 294   have_read_stdin = 0;
 295
 296   while ((c = getopt_long (argc, argv, "", long_options, (int *) 0)) != EOF)
 297     {
 298       switch (c)
 299         {
 300         case 0:
 301           break;
 302
 303         default:
 304           usage (1);
 305         }
 306     }
 307
 308   if (show_version)
 309     {
 310       printf ("cksum - %s\n", version_string);
 311       exit (0);
 312     }
 313
 314   if (show_help)
 315     usage (0);
 316
 317   if (optind >= argc)
 318     {
 319       if (cksum ("-", 0) < 0)
 320         errors = 1;
 321     }
 322   else
 323     {
 324       for (i = optind; i < argc; i++)
 325         if (cksum (argv[i], 1) < 0)
 326           errors = 1;
 327     }
 328
 329   if (have_read_stdin && fclose (stdin) == EOF)
 330     error (1, errno, "-");
 331   exit (errors);
 332 }
 333
 334 #endif /* !CRCTAB */