summaryrefslogtreecommitdiff
path: root/src/sum.c
blob: f43917fb23b1995bad5cb12ee6cdaa413ab0e2e0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
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
60
61
62
63
64
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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
/* sum -- checksum and count the blocks in a file
   Copyright (C) 1986, 1989, 1991, 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.  */

/* Like BSD sum or SysV sum -r, except like SysV sum if -s option is given. */

/* Written by Kayvan Aghaiepour and David MacKenzie. */

#include <config.h>

#include <stdio.h>
#include <sys/types.h>
#include <getopt.h>
#include "system.h"
#include "version.h"
#include "error.h"

int safe_read ();

/* The name this program was run with. */
char *program_name;

/* Nonzero if any of the files read were the standard input. */
static int have_read_stdin;

/* Right-rotate 32-bit integer variable C. */
#define ROTATE_RIGHT(c) if ((c) & 01) (c) = ((c) >>1) + 0x8000; else (c) >>= 1;

/* If non-zero, display usage information and exit.  */
static int show_help;

/* If non-zero, print the version on standard output then exit.  */
static int show_version;

static struct option const longopts[] =
{
  {"sysv", no_argument, NULL, 's'},
  {"help", no_argument, &show_help, 1},
  {"version", no_argument, &show_version, 1},
  {NULL, 0, NULL, 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 checksum and block counts for each FILE.\n\
\n\
  -r              defeat -s, use BSD sum algorithm, use 1K blocks\n\
  -s, --sysv      use System V sum algorithm, use 512 bytes blocks\n\
      --help      display this help and exit\n\
      --version   output version information and exit\n\
\n\
With no FILE, or when FILE is -, read standard input.\n\
"));
    }
  exit (status);
}

/* Calculate and print the rotated checksum and the size in 1K blocks
   of file FILE, or of the standard input if FILE is "-".
   If PRINT_NAME is >1, print FILE next to the checksum and size.
   The checksum varies depending on sizeof(int).
   Return 0 if successful, -1 if an error occurs. */

static int
bsd_sum_file (const char *file, int print_name)
{
  register FILE *fp;
  register unsigned long checksum = 0; /* The checksum mod 2^16. */
  register long total_bytes = 0; /* The number of bytes. */
  register int ch;		/* Each character read. */

  if (!strcmp (file, "-"))
    {
      fp = stdin;
      have_read_stdin = 1;
    }
  else
    {
      fp = fopen (file, "r");
      if (fp == NULL)
	{
	  error (0, errno, "%s", file);
	  return -1;
	}
    }

  /* This algorithm seems to depend on sign extension in `ch' in order to
     give the right results.  Ick.  */
  while ((ch = getc (fp)) != EOF)
    {
      total_bytes++;
      ROTATE_RIGHT (checksum);
      checksum += ch;
      checksum &= 0xffff;	/* Keep it within bounds. */
    }

  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;
    }

  printf ("%05lu %5ld", checksum, (total_bytes + 1024 - 1) / 1024);
  if (print_name > 1)
    printf (" %s", file);
  putchar ('\n');

  return 0;
}

/* Calculate and print the checksum and the size in 512-byte blocks
   of file FILE, or of the standard input if FILE is "-".
   If PRINT_NAME is >0, print FILE next to the checksum and size.
   Return 0 if successful, -1 if an error occurs. */

static int
sysv_sum_file (const char *file, int print_name)
{
  int fd;
  unsigned char buf[8192];
  register int bytes_read;
  register unsigned long checksum = 0;
  long total_bytes = 0;

  if (!strcmp (file, "-"))
    {
      fd = 0;
      have_read_stdin = 1;
    }
  else
    {
      fd = open (file, O_RDONLY);
      if (fd == -1)
	{
	  error (0, errno, "%s", file);
	  return -1;
	}
    }

  while ((bytes_read = safe_read (fd, buf, sizeof buf)) > 0)
    {
      register int i;

      for (i = 0; i < bytes_read; i++)
	checksum += buf[i];
      total_bytes += bytes_read;
    }

  if (bytes_read < 0)
    {
      error (0, errno, "%s", file);
      if (strcmp (file, "-"))
	close (fd);
      return -1;
    }

  if (strcmp (file, "-") && close (fd) == -1)
    {
      error (0, errno, "%s", file);
      return -1;
    }

  printf ("%lu %ld", checksum % 0xffff, (total_bytes + 512 - 1) / 512);
  if (print_name)
    printf (" %s", file);
  putchar ('\n');

  return 0;
}

void
main (int argc, char **argv)
{
  int errors = 0;
  int optc;
  int files_given;
  int (*sum_func) () = bsd_sum_file;

  program_name = argv[0];
  have_read_stdin = 0;

  while ((optc = getopt_long (argc, argv, "rs", longopts, (int *) 0)) != -1)
    {
      switch (optc)
	{
	case 0:
	  break;

	case 'r':		/* For SysV compatibility. */
	  sum_func = bsd_sum_file;
	  break;

	case 's':
	  sum_func = sysv_sum_file;
	  break;

	default:
	  usage (1);
	}
    }

  if (show_version)
    {
      printf ("sum - %s\n", version_string);
      exit (0);
    }

  if (show_help)
    usage (0);

  files_given = argc - optind;
  if (files_given == 0)
    {
      if ((*sum_func) ("-", files_given) < 0)
	errors = 1;
    }
  else
    for (; optind < argc; optind++)
      if ((*sum_func) (argv[optind], files_given) < 0)
	errors = 1;

  if (have_read_stdin && fclose (stdin) == EOF)
    error (1, errno, "-");
  exit (errors);
}