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 //config:config SUM
16 //config: bool "sum (4 kb)"
17 //config: default y
18 //config: help
19 //config: checksum and count the blocks in a file
20
21 //applet:IF_SUM(APPLET(sum, BB_DIR_USR_BIN, BB_SUID_DROP))
22
23 //kbuild:lib-$(CONFIG_SUM) += sum.o
24
25 //usage:#define sum_trivial_usage
26 //usage: "[-rs] [FILE]..."
27 //usage:#define sum_full_usage "\n\n"
28 //usage: "Checksum and count the blocks in a file\n"
29 //usage: "\n -r Use BSD sum algorithm (1K blocks)"
30 //usage: "\n -s Use System V sum algorithm (512byte blocks)"
31
32 #include "libbb.h"
33 #include "common_bufsiz.h"
34
35 enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
36
37 /* BSD: calculate and print the rotated checksum and the size in 1K blocks
38 The checksum varies depending on sizeof (int). */
39 /* SYSV: calculate and print the checksum and the size in 512-byte blocks */
40 /* Return 1 if successful. */
sum_file(const char * file,unsigned type)41 static unsigned sum_file(const char *file, unsigned type)
42 {
43 unsigned long long total_bytes = 0;
44 int fd, r;
45 /* The sum of all the input bytes, modulo (UINT_MAX + 1). */
46 unsigned s = 0;
47
48 #define buf bb_common_bufsiz1
49 setup_common_bufsiz();
50
51 fd = open_or_warn_stdin(file);
52 if (fd == -1)
53 return 0;
54
55 while (1) {
56 size_t bytes_read = safe_read(fd, buf, COMMON_BUFSIZE);
57
58 if ((ssize_t)bytes_read <= 0) {
59 r = (fd && close(fd) != 0);
60 if (!bytes_read && !r)
61 /* no error */
62 break;
63 bb_simple_perror_msg(file);
64 return 0;
65 }
66
67 total_bytes += bytes_read;
68 if (type >= SUM_SYSV) {
69 do s += buf[--bytes_read]; while (bytes_read);
70 } else {
71 r = 0;
72 do {
73 s = (s >> 1) + ((s & 1) << 15);
74 s += buf[r++];
75 s &= 0xffff; /* Keep it within bounds. */
76 } while (--bytes_read);
77 }
78 }
79
80 if (type < PRINT_NAME)
81 file = "";
82 if (type >= SUM_SYSV) {
83 r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
84 s = (r & 0xffff) + (r >> 16);
85 printf("%u %llu %s\n", s, (total_bytes + 511) / 512, file);
86 } else
87 printf("%05u %5llu %s\n", s, (total_bytes + 1023) / 1024, file);
88 return 1;
89 #undef buf
90 }
91
92 int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
sum_main(int argc UNUSED_PARAM,char ** argv)93 int sum_main(int argc UNUSED_PARAM, char **argv)
94 {
95 unsigned n;
96 unsigned type = SUM_BSD;
97
98 n = getopt32(argv, "sr");
99 argv += optind;
100 if (n & 1) type = SUM_SYSV;
101 /* give the bsd priority over sysv func */
102 if (n & 2) type = SUM_BSD;
103
104 if (!argv[0]) {
105 /* Do not print the name */
106 n = sum_file("-", type);
107 } else {
108 /* Need to print the name if either
109 * - more than one file given
110 * - doing sysv */
111 type += (argv[1] || type == SUM_SYSV);
112 n = 1;
113 do {
114 n &= sum_file(*argv, type);
115 } while (*++argv);
116 }
117 return !n;
118 }
119