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 //config: bool "sum (4.3 kb)"
19 //config: checksum and count the blocks in a file
21 //applet:IF_SUM(APPLET(sum, BB_DIR_USR_BIN, BB_SUID_DROP))
23 //kbuild:lib-$(CONFIG_SUM) += sum.o
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)"
33 #include "common_bufsiz.h"
35 enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
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. */
41 static unsigned sum_file(const char *file, unsigned type)
43 unsigned long long total_bytes = 0;
45 /* The sum of all the input bytes, modulo (UINT_MAX + 1). */
48 #define buf bb_common_bufsiz1
49 setup_common_bufsiz();
51 fd = open_or_warn_stdin(file);
56 size_t bytes_read = safe_read(fd, buf, COMMON_BUFSIZE);
58 if ((ssize_t)bytes_read <= 0) {
59 r = (fd && close(fd) != 0);
60 if (!bytes_read && !r)
63 bb_simple_perror_msg(file);
67 total_bytes += bytes_read;
68 if (type >= SUM_SYSV) {
69 do s += buf[--bytes_read]; while (bytes_read);
73 s = (s >> 1) + ((s & 1) << 15);
75 s &= 0xffff; /* Keep it within bounds. */
76 } while (--bytes_read);
80 if (type < PRINT_NAME)
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);
87 printf("%05u %5llu %s\n", s, (total_bytes + 1023) / 1024, file);
92 int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
93 int sum_main(int argc UNUSED_PARAM, char **argv)
96 unsigned type = SUM_BSD;
98 n = getopt32(argv, "sr");
100 if (n & 1) type = SUM_SYSV;
101 /* give the bsd priority over sysv func */
102 if (n & 2) type = SUM_BSD;
105 /* Do not print the name */
106 n = sum_file("-", type);
108 /* Need to print the name if either
109 * - more than one file given
111 type += (argv[1] || type == SUM_SYSV);
114 n &= sum_file(*argv, type);