Contents of /tags/mkinitrd-6_3_3/busybox/coreutils/sum.c
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Wed Dec 15 21:43:57 2010 UTC (13 years, 9 months ago) by niro
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Wed Dec 15 21:43:57 2010 UTC (13 years, 9 months ago) by niro
File MIME type: text/plain
File size: 2558 byte(s)
tagged 'mkinitrd-6_3_3'
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_simple_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 | } |