1 /* vi: set sw=4 ts=4: */
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.
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>
10 * Written by Kayvan Aghaiepour and David MacKenzie
11 * Taken from coreutils and turned into a busybox applet by Mike Frysinger
13 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
16 //usage:#define sum_trivial_usage
17 //usage: "[-rs] [FILE]..."
18 //usage:#define sum_full_usage "\n\n"
19 //usage: "Checksum and count the blocks in a file\n"
20 //usage: "\n -r Use BSD sum algorithm (1K blocks)"
21 //usage: "\n -s Use System V sum algorithm (512byte blocks)"
24 #include "common_bufsiz.h"
26 enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
28 /* BSD: calculate and print the rotated checksum and the size in 1K blocks
29 The checksum varies depending on sizeof (int). */
30 /* SYSV: calculate and print the checksum and the size in 512-byte blocks */
31 /* Return 1 if successful. */
32 static unsigned sum_file(const char *file, unsigned type)
34 unsigned long long total_bytes = 0;
36 /* The sum of all the input bytes, modulo (UINT_MAX + 1). */
39 #define buf bb_common_bufsiz1
40 setup_common_bufsiz();
42 fd = open_or_warn_stdin(file);
47 size_t bytes_read = safe_read(fd, buf, COMMON_BUFSIZE);
49 if ((ssize_t)bytes_read <= 0) {
50 r = (fd && close(fd) != 0);
51 if (!bytes_read && !r)
54 bb_simple_perror_msg(file);
58 total_bytes += bytes_read;
59 if (type >= SUM_SYSV) {
60 do s += buf[--bytes_read]; while (bytes_read);
64 s = (s >> 1) + ((s & 1) << 15);
66 s &= 0xffff; /* Keep it within bounds. */
67 } while (--bytes_read);
71 if (type < PRINT_NAME)
73 if (type >= SUM_SYSV) {
74 r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
75 s = (r & 0xffff) + (r >> 16);
76 printf("%u %llu %s\n", s, (total_bytes + 511) / 512, file);
78 printf("%05u %5llu %s\n", s, (total_bytes + 1023) / 1024, file);
83 int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
84 int sum_main(int argc UNUSED_PARAM, char **argv)
87 unsigned type = SUM_BSD;
89 n = getopt32(argv, "sr");
91 if (n & 1) type = SUM_SYSV;
92 /* give the bsd priority over sysv func */
93 if (n & 2) type = SUM_BSD;
96 /* Do not print the name */
97 n = sum_file("-", type);
99 /* Need to print the name if either
100 * - more than one file given
102 type += (argv[1] || type == SUM_SYSV);
105 n &= sum_file(*argv, type);