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/* vi: set sw=4 ts=4: */
/*
* sum -- checksum and count the blocks in a file
* Like BSD sum or SysV sum -r, except like SysV sum if -s option is given.
*
* Copyright (C) 86, 89, 91, 1995-2002, 2004 Free Software Foundation, Inc.
* Copyright (C) 2005 by Erik Andersen <andersen@codepoet.org>
* Copyright (C) 2005 by Mike Frysinger <vapier@gentoo.org>
*
* Written by Kayvan Aghaiepour and David MacKenzie
* Taken from coreutils and turned into a busybox applet by Mike Frysinger
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config SUM
//config: bool "sum (4 kb)"
//config: default y
//config: help
//config: checksum and count the blocks in a file
//applet:IF_SUM(APPLET(sum, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_SUM) += sum.o
//usage:#define sum_trivial_usage
//usage: "[-rs] [FILE]..."
//usage:#define sum_full_usage "\n\n"
//usage: "Checksum and count the blocks in a file\n"
//usage: "\n -r Use BSD sum algorithm (1K blocks)"
//usage: "\n -s Use System V sum algorithm (512byte blocks)"
#include "libbb.h"
#include "common_bufsiz.h"
enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
/* BSD: calculate and print the rotated checksum and the size in 1K blocks
The checksum varies depending on sizeof (int). */
/* SYSV: calculate and print the checksum and the size in 512-byte blocks */
/* Return 1 if successful. */
static unsigned sum_file(const char *file, unsigned type)
{
unsigned long long total_bytes = 0;
int fd, r;
/* The sum of all the input bytes, modulo (UINT_MAX + 1). */
unsigned s = 0;
#define buf bb_common_bufsiz1
setup_common_bufsiz();
fd = open_or_warn_stdin(file);
if (fd == -1)
return 0;
while (1) {
size_t bytes_read = safe_read(fd, buf, COMMON_BUFSIZE);
if ((ssize_t)bytes_read <= 0) {
r = (fd && close(fd) != 0);
if (!bytes_read && !r)
/* no error */
break;
bb_simple_perror_msg(file);
return 0;
}
total_bytes += bytes_read;
if (type >= SUM_SYSV) {
do s += buf[--bytes_read]; while (bytes_read);
} else {
r = 0;
do {
s = (s >> 1) + ((s & 1) << 15);
s += buf[r++];
s &= 0xffff; /* Keep it within bounds. */
} while (--bytes_read);
}
}
if (type < PRINT_NAME)
file = "";
if (type >= SUM_SYSV) {
r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
s = (r & 0xffff) + (r >> 16);
printf("%u %llu %s\n", s, (total_bytes + 511) / 512, file);
} else
printf("%05u %5llu %s\n", s, (total_bytes + 1023) / 1024, file);
return 1;
#undef buf
}
int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int sum_main(int argc UNUSED_PARAM, char **argv)
{
unsigned n;
unsigned type = SUM_BSD;
n = getopt32(argv, "sr");
argv += optind;
if (n & 1) type = SUM_SYSV;
/* give the bsd priority over sysv func */
if (n & 2) type = SUM_BSD;
if (!argv[0]) {
/* Do not print the name */
n = sum_file("-", type);
} else {
/* Need to print the name if either
* - more than one file given
* - doing sysv */
type += (argv[1] || type == SUM_SYSV);
n = 1;
do {
n &= sum_file(*argv, type);
} while (*++argv);
}
return !n;
}
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