box/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, const unsigned type)
  25 {
  26 #define buf bb_common_bufsiz1
  27 #ifdef __MINGW32__
  28         unsigned int total_bytes = 0;
  29 #else
  30         uintmax_t total_bytes = 0;
  31 #endif
  32         int fd = 0, r;
  33
  34         /* The sum of all the input bytes, modulo (UINT_MAX + 1).  */
  35         unsigned s = 0;
  36
  37         if (NOT_LONE_DASH(file)) {
  38                 fd = open(file, O_RDONLY);
  39                 if (fd == -1)
  40                         goto ret_bad;
  41         }
  42
  43         while (1) {
  44                 size_t bytes_read = safe_read(fd, buf, BUFSIZ);
  45
  46                 if ((ssize_t)bytes_read <= 0) {
  47                         r = (fd && close(fd) != 0);
  48                         if (!bytes_read && !r)
  49                                 /* no error */
  50                                 break;
  51  ret_bad:
  52                         bb_perror_msg(file);
  53                         return 0;
  54                 }
  55
  56                 total_bytes += bytes_read;
  57                 if (type >= SUM_SYSV) {
  58                         do s += buf[--bytes_read]; while (bytes_read);
  59                 } else {
  60                         r = 0;
  61                         do {
  62                                 s = (s >> 1) + ((s & 1) << 15);
  63                                 s += buf[r++];
  64                                 s &= 0xffff; /* Keep it within bounds. */
  65                         } while (--bytes_read);
  66                 }
  67         }
  68
  69         if (type < PRINT_NAME)
  70                 file = "";
  71         if (type >= SUM_SYSV) {
  72                 r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
  73                 s = (r & 0xffff) + (r >> 16);
  74 #ifdef __MINGW32__
  75                 printf("%d %u %s\n", s, (total_bytes+511)/512, file);
  76 #else
  77                 printf("%d %ju %s\n", s, (total_bytes+511)/512, file);
  78 #endif
  79         } else
  80 #ifdef __MINGW32__
  81                 printf("%05d %5u %s\n", s, (total_bytes+1023)/1024, file);
  82 #else
  83                 printf("%05d %5ju %s\n", s, (total_bytes+1023)/1024, file);
  84 #endif
  85         return 1;
  86 #undef buf
  87 }
  88
  89 int sum_main(int argc, char **argv);
  90 int sum_main(int argc, char **argv)
  91 {
  92         unsigned n;
  93         unsigned type = SUM_BSD;
  94
  95         n = getopt32(argc, argv, "sr");
  96         if (n & 1) type = SUM_SYSV;
  97         /* give the bsd priority over sysv func */
  98         if (n & 2) type = SUM_BSD;
  99
 100         if (argc == optind) {
 101                 /* Do not print the name */
 102                 n = sum_file("-", type);
 103         } else {
 104                 /* Need to print the name if either
 105                    - more than one file given
 106                    - doing sysv */
 107                 type += argc - 1 > optind || type == SUM_SYSV;
 108                 for (n = 1; optind < argc; optind++)
 109                         n &= sum_file(argv[optind], type);
 110         }
 111         return !n;
 112 }