blob: deb068e1024e7501d0db6e5e130cb2402ecf4221
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 GPLv2 or later, see file LICENSE in this source tree. |
14 | */ |
15 | |
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)" |
22 | |
23 | #include "libbb.h" |
24 | |
25 | enum { SUM_BSD, PRINT_NAME, SUM_SYSV }; |
26 | |
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) |
32 | { |
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; |
38 | |
39 | fd = open_or_warn_stdin(file); |
40 | if (fd == -1) |
41 | return 0; |
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 | bb_simple_perror_msg(file); |
52 | return 0; |
53 | } |
54 | |
55 | total_bytes += bytes_read; |
56 | if (type >= SUM_SYSV) { |
57 | do s += buf[--bytes_read]; while (bytes_read); |
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. */ |
64 | } while (--bytes_read); |
65 | } |
66 | } |
67 | |
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("%u %llu %s\n", s, (total_bytes + 511) / 512, file); |
74 | } else |
75 | printf("%05u %5llu %s\n", s, (total_bytes + 1023) / 1024, file); |
76 | return 1; |
77 | #undef buf |
78 | } |
79 | |
80 | int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
81 | int sum_main(int argc UNUSED_PARAM, char **argv) |
82 | { |
83 | unsigned n; |
84 | unsigned type = SUM_BSD; |
85 | |
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; |
91 | |
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); |
104 | } |
105 | return !n; |
106 | } |
107 |