blob 75f6ef60a2f6abd747ffb514fcdc2e46a4b32203
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.
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)"
23 #include "libbb.h"
25 enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
27 /* BSD: calculate and print the rotated checksum and the size in 1K blocks
28 The checksum varies depending on sizeof (int). */
29 /* SYSV: calculate and print the checksum and the size in 512-byte blocks */
30 /* Return 1 if successful. */
31 static unsigned sum_file(const char *file, unsigned type)
33 #define buf bb_common_bufsiz1
34 unsigned long long total_bytes = 0;
35 int fd, r;
36 /* The sum of all the input bytes, modulo (UINT_MAX + 1). */
37 unsigned s = 0;
39 fd = open_or_warn_stdin(file);
40 if (fd == -1)
41 return 0;
43 while (1) {
46 if ((ssize_t)bytes_read <= 0) {
47 r = (fd && close(fd) != 0);
49 /* no error */
50 break;
51 bb_simple_perror_msg(file);
52 return 0;
56 if (type >= SUM_SYSV) {
58 } else {
59 r = 0;
60 do {
61 s = (s >> 1) + ((s & 1) << 15);
62 s += buf[r++];
63 s &= 0xffff; /* Keep it within bounds. */
68 if (type < PRINT_NAME)
69 file = "";
70 if (type >= SUM_SYSV) {
71 r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
72 s = (r & 0xffff) + (r >> 16);
73 printf("%d %llu %s\n", s, (total_bytes + 511) / 512, file);
74 } else
75 printf("%05d %5llu %s\n", s, (total_bytes + 1023) / 1024, file);
76 return 1;
77 #undef buf
80 int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
81 int sum_main(int argc UNUSED_PARAM, char **argv)
83 unsigned n;
84 unsigned type = SUM_BSD;
86 n = getopt32(argv, "sr");
87 argv += optind;
88 if (n & 1) type = SUM_SYSV;
89 /* give the bsd priority over sysv func */
90 if (n & 2) type = SUM_BSD;
92 if (!argv[0]) {
93 /* Do not print the name */
94 n = sum_file("-", type);
95 } else {
96 /* Need to print the name if either
97 * - more than one file given
98 * - doing sysv */
99 type += (argv[1] || type == SUM_SYSV);
100 n = 1;
101 do {
102 n &= sum_file(*argv, type);
103 } while (*++argv);
105 return !n;