release/src/router/busybox/coreutils/sum.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * sum -- checksum and count the blocks in a file
   4  *     Like BSD sum or SysV sum -r, except like SysV sum if -s option is given.
   5  *
   6  * Copyright (C) 86, 89, 91, 1995-2002, 2004 Free Software Foundation, Inc.
   7  * Copyright (C) 2005 by Erik Andersen <andersen@codepoet.org>
   8  * Copyright (C) 2005 by Mike Frysinger <vapier@gentoo.org>
   9  *
  10  * Written by Kayvan Aghaiepour and David MacKenzie
  11  * Taken from coreutils and turned into a busybox applet by Mike Frysinger
  12  *
  13  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  14  */
  15
  16 #include "libbb.h"
  17
  18 enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
  19
  20 /* BSD: calculate and print the rotated checksum and the size in 1K blocks
  21    The checksum varies depending on sizeof (int). */
  22 /* SYSV: calculate and print the checksum and the size in 512-byte blocks */
  23 /* Return 1 if successful.  */
  24 static unsigned sum_file(const char *file, unsigned type)
  25 {
  26 #define buf bb_common_bufsiz1
  27         unsigned long long total_bytes = 0;
  28         int fd, r;
  29         /* The sum of all the input bytes, modulo (UINT_MAX + 1).  */
  30         unsigned s = 0;
  31
  32         fd = open_or_warn_stdin(file);
  33         if (fd == -1)
  34                 return 0;
  35
  36         while (1) {
  37                 size_t bytes_read = safe_read(fd, buf, BUFSIZ);
  38
  39                 if ((ssize_t)bytes_read <= 0) {
  40                         r = (fd && close(fd) != 0);
  41                         if (!bytes_read && !r)
  42                                 /* no error */
  43                                 break;
  44                         bb_perror_msg(file);
  45                         return 0;
  46                 }
  47
  48                 total_bytes += bytes_read;
  49                 if (type >= SUM_SYSV) {
  50                         do s += buf[--bytes_read]; while (bytes_read);
  51                 } else {
  52                         r = 0;
  53                         do {
  54                                 s = (s >> 1) + ((s & 1) << 15);
  55                                 s += buf[r++];
  56                                 s &= 0xffff; /* Keep it within bounds. */
  57                         } while (--bytes_read);
  58                 }
  59         }
  60
  61         if (type < PRINT_NAME)
  62                 file = "";
  63         if (type >= SUM_SYSV) {
  64                 r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
  65                 s = (r & 0xffff) + (r >> 16);
  66                 printf("%d %llu %s\n", s, (total_bytes + 511) / 512, file);
  67         } else
  68                 printf("%05d %5llu %s\n", s, (total_bytes + 1023) / 1024, file);
  69         return 1;
  70 #undef buf
  71 }
  72
  73 int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  74 int sum_main(int argc UNUSED_PARAM, char **argv)
  75 {
  76         unsigned n;
  77         unsigned type = SUM_BSD;
  78
  79         n = getopt32(argv, "sr");
  80         argv += optind;
  81         if (n & 1) type = SUM_SYSV;
  82         /* give the bsd priority over sysv func */
  83         if (n & 2) type = SUM_BSD;
  84
  85         if (!argv[0]) {
  86                 /* Do not print the name */
  87                 n = sum_file("-", type);
  88         } else {
  89                 /* Need to print the name if either
  90                    - more than one file given
  91                    - doing sysv */
  92                 type += (argv[1] || type == SUM_SYSV);
  93                 n = 1;
  94                 do {
  95                         n &= sum_file(*argv, type);
  96                 } while (*++argv);
  97         }
  98         return !n;
  99 }