101 lines
2.5 KiB
C
101 lines
2.5 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* sum -- checksum and count the blocks in a file
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* Like BSD sum or SysV sum -r, except like SysV sum if -s option is given.
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*
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* Copyright (C) 86, 89, 91, 1995-2002, 2004 Free Software Foundation, Inc.
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* Copyright (C) 2005 by Erik Andersen <andersen@codepoet.org>
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* Copyright (C) 2005 by Mike Frysinger <vapier@gentoo.org>
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*
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* Written by Kayvan Aghaiepour and David MacKenzie
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* Taken from coreutils and turned into a busybox applet by Mike Frysinger
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*
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* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
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*/
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#include "libbb.h"
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enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
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/* BSD: calculate and print the rotated checksum and the size in 1K blocks
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The checksum varies depending on sizeof (int). */
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/* SYSV: calculate and print the checksum and the size in 512-byte blocks */
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/* Return 1 if successful. */
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static unsigned sum_file(const char *file, const unsigned type)
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{
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#define buf bb_common_bufsiz1
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unsigned long long total_bytes = 0;
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int fd = 0, r;
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/* The sum of all the input bytes, modulo (UINT_MAX + 1). */
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unsigned s = 0;
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if (NOT_LONE_DASH(file)) {
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fd = open(file, O_RDONLY);
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if (fd == -1)
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goto ret_bad;
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}
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while (1) {
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size_t bytes_read = safe_read(fd, buf, BUFSIZ);
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if ((ssize_t)bytes_read <= 0) {
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r = (fd && close(fd) != 0);
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if (!bytes_read && !r)
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/* no error */
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break;
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ret_bad:
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bb_perror_msg(file);
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return 0;
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}
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total_bytes += bytes_read;
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if (type >= SUM_SYSV) {
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do s += buf[--bytes_read]; while (bytes_read);
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} else {
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r = 0;
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do {
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s = (s >> 1) + ((s & 1) << 15);
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s += buf[r++];
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s &= 0xffff; /* Keep it within bounds. */
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} while (--bytes_read);
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}
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}
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if (type < PRINT_NAME)
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file = "";
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if (type >= SUM_SYSV) {
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r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
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s = (r & 0xffff) + (r >> 16);
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printf("%d %llu %s\n", s, (total_bytes + 511) / 512, file);
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} else
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printf("%05d %5llu %s\n", s, (total_bytes + 1023) / 1024, file);
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return 1;
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#undef buf
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}
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int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int sum_main(int argc, char **argv)
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{
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unsigned n;
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unsigned type = SUM_BSD;
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n = getopt32(argv, "sr");
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if (n & 1) type = SUM_SYSV;
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/* give the bsd priority over sysv func */
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if (n & 2) type = SUM_BSD;
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if (argc == optind) {
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/* Do not print the name */
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n = sum_file("-", type);
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} else {
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/* Need to print the name if either
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- more than one file given
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- doing sysv */
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type += argc - 1 > optind || type == SUM_SYSV;
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for (n = 1; optind < argc; optind++)
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n &= sum_file(argv[optind], type);
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}
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return !n;
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}
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