src/sum.c

   1 /* sum -- checksum and count the blocks in a file
   2    Copyright (C) 86, 89, 91, 1995-2002, 2004 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 Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Like BSD sum or SysV sum -r, except like SysV sum if -s option is given. */
  19
  20 /* Written by Kayvan Aghaiepour and David MacKenzie. */
  21
  22 #include <config.h>
  23
  24 #include <stdio.h>
  25 #include <sys/types.h>
  26 #include <getopt.h>
  27 #include "system.h"
  28 #include "error.h"
  29 #include "human.h"
  30 #include "safe-read.h"
  31
  32 /* The official name of this program (e.g., no `g' prefix).  */
  33 #define PROGRAM_NAME "sum"
  34
  35 #define AUTHORS "Kayvan Aghaiepour", "David MacKenzie"
  36
  37 /* The name this program was run with. */
  38 char *program_name;
  39
  40 /* Nonzero if any of the files read were the standard input. */
  41 static int have_read_stdin;
  42
  43 static struct option const longopts[] =
  44 {
  45   {"sysv", no_argument, NULL, 's'},
  46   {GETOPT_HELP_OPTION_DECL},
  47   {GETOPT_VERSION_OPTION_DECL},
  48   {NULL, 0, NULL, 0}
  49 };
  50
  51 void
  52 usage (int status)
  53 {
  54   if (status != EXIT_SUCCESS)
  55     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  56              program_name);
  57   else
  58     {
  59       printf (_("\
  60 Usage: %s [OPTION]... [FILE]...\n\
  61 "),
  62               program_name);
  63       fputs (_("\
  64 Print checksum and block counts for each FILE.\n\
  65 \n\
  66   -r              defeat -s, use BSD sum algorithm, use 1K blocks\n\
  67   -s, --sysv      use System V sum algorithm, use 512 bytes blocks\n\
  68 "), stdout);
  69       fputs (HELP_OPTION_DESCRIPTION, stdout);
  70       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  71       fputs (_("\
  72 \n\
  73 With no FILE, or when FILE is -, read standard input.\n\
  74 "), stdout);
  75       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
  76     }
  77   exit (status);
  78 }
  79
  80 /* Calculate and print the rotated checksum and the size in 1K blocks
  81    of file FILE, or of the standard input if FILE is "-".
  82    If PRINT_NAME is >1, print FILE next to the checksum and size.
  83    The checksum varies depending on sizeof(int).
  84    Return 0 if successful, -1 if an error occurs. */
  85
  86 static int
  87 bsd_sum_file (const char *file, int print_name)
  88 {
  89   register FILE *fp;
  90   register int checksum = 0;    /* The checksum mod 2^16. */
  91   register uintmax_t total_bytes = 0;   /* The number of bytes. */
  92   register int ch;              /* Each character read. */
  93   char hbuf[LONGEST_HUMAN_READABLE + 1];
  94
  95   if (STREQ (file, "-"))
  96     {
  97       fp = stdin;
  98       have_read_stdin = 1;
  99     }
 100   else
 101     {
 102       fp = fopen (file, "r");
 103       if (fp == NULL)
 104         {
 105           error (0, errno, "%s", file);
 106           return -1;
 107         }
 108     }
 109   /* Need binary I/O, or else byte counts and checksums are incorrect.  */
 110   SET_BINARY (fileno(fp));
 111
 112   while ((ch = getc (fp)) != EOF)
 113     {
 114       total_bytes++;
 115       checksum = (checksum >> 1) + ((checksum & 1) << 15);
 116       checksum += ch;
 117       checksum &= 0xffff;       /* Keep it within bounds. */
 118     }
 119
 120   if (ferror (fp))
 121     {
 122       error (0, errno, "%s", file);
 123       if (!STREQ (file, "-"))
 124         fclose (fp);
 125       return -1;
 126     }
 127
 128   if (!STREQ (file, "-") && fclose (fp) == EOF)
 129     {
 130       error (0, errno, "%s", file);
 131       return -1;
 132     }
 133
 134   printf ("%05d %5s", checksum,
 135           human_readable (total_bytes, hbuf, human_ceiling, 1, 1024));
 136   if (print_name > 1)
 137     printf (" %s", file);
 138   putchar ('\n');
 139
 140   return 0;
 141 }
 142
 143 /* Calculate and print the checksum and the size in 512-byte blocks
 144    of file FILE, or of the standard input if FILE is "-".
 145    If PRINT_NAME is >0, print FILE next to the checksum and size.
 146    Return 0 if successful, -1 if an error occurs. */
 147
 148 static int
 149 sysv_sum_file (const char *file, int print_name)
 150 {
 151   int fd;
 152   unsigned char buf[8192];
 153   uintmax_t total_bytes = 0;
 154   char hbuf[LONGEST_HUMAN_READABLE + 1];
 155   int r;
 156   int checksum;
 157
 158   /* The sum of all the input bytes, modulo (UINT_MAX + 1).  */
 159   unsigned int s = 0;
 160
 161   if (STREQ (file, "-"))
 162     {
 163       fd = 0;
 164       have_read_stdin = 1;
 165     }
 166   else
 167     {
 168       fd = open (file, O_RDONLY);
 169       if (fd == -1)
 170         {
 171           error (0, errno, "%s", file);
 172           return -1;
 173         }
 174     }
 175   /* Need binary I/O, or else byte counts and checksums are incorrect.  */
 176   SET_BINARY (fd);
 177
 178   while (1)
 179     {
 180       size_t i;
 181       size_t bytes_read = safe_read (fd, buf, sizeof buf);
 182
 183       if (bytes_read == 0)
 184         break;
 185
 186       if (bytes_read == SAFE_READ_ERROR)
 187         {
 188           error (0, errno, "%s", file);
 189           if (!STREQ (file, "-"))
 190             close (fd);
 191           return -1;
 192         }
 193
 194       for (i = 0; i < bytes_read; i++)
 195         s += buf[i];
 196       total_bytes += bytes_read;
 197     }
 198
 199   if (!STREQ (file, "-") && close (fd) == -1)
 200     {
 201       error (0, errno, "%s", file);
 202       return -1;
 203     }
 204
 205   r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
 206   checksum = (r & 0xffff) + (r >> 16);
 207
 208   printf ("%d %s", checksum,
 209           human_readable (total_bytes, hbuf, human_ceiling, 1, 512));
 210   if (print_name)
 211     printf (" %s", file);
 212   putchar ('\n');
 213
 214   return 0;
 215 }
 216
 217 int
 218 main (int argc, char **argv)
 219 {
 220   int errors = 0;
 221   int optc;
 222   int files_given;
 223   int (*sum_func) (const char *, int) = bsd_sum_file;
 224
 225   initialize_main (&argc, &argv);
 226   program_name = argv[0];
 227   setlocale (LC_ALL, "");
 228   bindtextdomain (PACKAGE, LOCALEDIR);
 229   textdomain (PACKAGE);
 230
 231   atexit (close_stdout);
 232
 233   have_read_stdin = 0;
 234
 235   while ((optc = getopt_long (argc, argv, "rs", longopts, NULL)) != -1)
 236     {
 237       switch (optc)
 238         {
 239         case 0:
 240           break;
 241
 242         case 'r':               /* For SysV compatibility. */
 243           sum_func = bsd_sum_file;
 244           break;
 245
 246         case 's':
 247           sum_func = sysv_sum_file;
 248           break;
 249
 250         case_GETOPT_HELP_CHAR;
 251
 252         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 253
 254         default:
 255           usage (EXIT_FAILURE);
 256         }
 257     }
 258
 259   files_given = argc - optind;
 260   if (files_given == 0)
 261     {
 262       if ((*sum_func) ("-", files_given) < 0)
 263         errors = 1;
 264     }
 265   else
 266     for (; optind < argc; optind++)
 267       if ((*sum_func) (argv[optind], files_given) < 0)
 268         errors = 1;
 269
 270   if (have_read_stdin && fclose (stdin) == EOF)
 271     error (EXIT_FAILURE, errno, "-");
 272   exit (errors == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
 273 }