mirror of
https://git.busybox.net/busybox.git
synced 2024-11-30 17:13:32 +08:00
da49e7057a
function old new delta cksum_main 281 262 -19 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
85 lines
2.0 KiB
C
85 lines
2.0 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* cksum - calculate the CRC32 checksum of a file
|
|
*
|
|
* Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
|
*/
|
|
//config:config CKSUM
|
|
//config: bool "cksum (4.2 kb)"
|
|
//config: default y
|
|
//config: help
|
|
//config: cksum is used to calculate the CRC32 checksum of a file.
|
|
|
|
//applet:IF_CKSUM(APPLET_NOEXEC(cksum, cksum, BB_DIR_USR_BIN, BB_SUID_DROP, cksum))
|
|
/* bb_common_bufsiz1 usage here is safe wrt NOEXEC: not expecting it to be zeroed. */
|
|
|
|
//kbuild:lib-$(CONFIG_CKSUM) += cksum.o
|
|
|
|
//usage:#define cksum_trivial_usage
|
|
//usage: "FILE..."
|
|
//usage:#define cksum_full_usage "\n\n"
|
|
//usage: "Calculate the CRC32 checksums of FILEs"
|
|
|
|
#include "libbb.h"
|
|
#include "common_bufsiz.h"
|
|
|
|
/* This is a NOEXEC applet. Be very careful! */
|
|
|
|
int cksum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
int cksum_main(int argc UNUSED_PARAM, char **argv)
|
|
{
|
|
uint32_t *crc32_table = crc32_filltable(NULL, 1);
|
|
int exit_code = EXIT_SUCCESS;
|
|
|
|
#if ENABLE_DESKTOP
|
|
getopt32(argv, ""); /* coreutils 6.9 compat */
|
|
argv += optind;
|
|
#else
|
|
argv++;
|
|
#endif
|
|
|
|
setup_common_bufsiz();
|
|
do {
|
|
uint32_t crc;
|
|
off_t filesize;
|
|
int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input);
|
|
|
|
if (fd < 0) {
|
|
exit_code = EXIT_FAILURE;
|
|
continue;
|
|
}
|
|
|
|
crc = 0;
|
|
filesize = 0;
|
|
#define read_buf bb_common_bufsiz1
|
|
for (;;) {
|
|
uoff_t t;
|
|
int bytes_read = safe_read(fd, read_buf, COMMON_BUFSIZE);
|
|
if (bytes_read > 0) {
|
|
filesize += bytes_read;
|
|
} else {
|
|
/* Checksum filesize bytes, LSB first, and exit */
|
|
close(fd);
|
|
fd = -1; /* break flag */
|
|
t = filesize;
|
|
bytes_read = 0;
|
|
while (t != 0) {
|
|
read_buf[bytes_read++] = (uint8_t)t;
|
|
t >>= 8;
|
|
}
|
|
}
|
|
crc = crc32_block_endian1(crc, read_buf, bytes_read, crc32_table);
|
|
if (fd < 0)
|
|
break;
|
|
}
|
|
|
|
crc = ~crc;
|
|
printf((*argv ? "%u %"OFF_FMT"u %s\n" : "%u %"OFF_FMT"u\n"),
|
|
(unsigned)crc, filesize, *argv);
|
|
} while (*argv && *++argv);
|
|
|
|
fflush_stdout_and_exit(exit_code);
|
|
}
|