usr/src/ucbcmd/sum/sum.c

   1 /*
   2  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5
   6 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
   7 /*        All Rights Reserved   */
   8
   9
  10 /*
  11  * Copyright (c) 1980 Regents of the University of California.
  12  * All rights reserved. The Berkeley software License Agreement
  13  * specifies the terms and conditions for redistribution.
  14  */
  15
  16 #pragma ident   "%Z%%M% %I%     %E% SMI"
  17
  18 /*
  19  * Sum bytes in file mod 2^16
  20  */
  21
  22 #include <stdio.h>
  23
  24 int
  25 main(int argc, char **argv)
  26 {
  27         unsigned int sum;
  28         int i, c;
  29         FILE *f;
  30         long long nbytes;
  31         int errflg = 0;
  32
  33         i = 1;
  34         do {
  35                 if (i < argc) {
  36                         if ((f = fopen(argv[i], "r")) == NULL) {
  37                                 (void) fprintf(stderr,
  38                                         "sum: Can't open %s\n", argv[i]);
  39                                 errflg += 10;
  40                                 continue;
  41                         }
  42                 } else
  43                         f = stdin;
  44                 sum = 0;
  45                 nbytes = 0;
  46                 while ((c = getc(f)) != EOF) {
  47                         nbytes++;
  48                         if (sum&01)
  49                                 sum = (sum>>1) + 0x8000;
  50                         else
  51                                 sum >>= 1;
  52                         sum += c;
  53                         sum &= 0xFFFF;
  54                 }
  55                 if (ferror(f)) {
  56                         errflg++;
  57                         (void) fprintf(stderr,
  58                                 "sum: read error on %s\n",
  59                                 argc > 1 ? argv[i] : "-");
  60                 }
  61
  62                 (void) printf("%05u %5lld", sum,
  63                         (nbytes + BUFSIZ - 1) / BUFSIZ);
  64                 if (argc > 2)
  65                         (void) printf(" %s", argv[i]);
  66                 (void) printf("\n");
  67                 (void) fclose(f);
  68         } while (++i < argc);
  69
  70         return (errflg);
  71 }