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crc32: new applet

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function                                             old     new   delta
cksum_main                                           258     377    +119
.rodata                                           103672  103681      +9
applet_names                                        2745    2751      +6
applet_main                                         1588    1592      +4
packed_usage                                       33734   33698     -36
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/1 up/down: 138/-36)           Total: 102 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-06-22 01:07:54 +02:00
parent 0ec52d438a
commit ea9b96e5aa
1 changed files with 27 additions and 15 deletions
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42
coreutils/cksum.c
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@ -9,32 +9,39 @@
//config:config CKSUM
//config: bool "cksum (4.1 kb)"
//config: default y
//config: help
//config: cksum is used to calculate the CRC32 checksum of a file.
//config:
//config:config CRC32
//config: bool "crc32 (4.1 kb)"
//config: default y
//applet:IF_CKSUM(APPLET_NOEXEC(cksum, cksum, BB_DIR_USR_BIN, BB_SUID_DROP, cksum))
//applet:IF_CKSUM(APPLET_NOEXEC(crc32, 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-$(CONFIG_CKSUM) += cksum.o
//kbuild:lib-$(CONFIG_CRC32) += cksum.o
//usage:#define cksum_trivial_usage
//usage: "FILE..."
//usage:#define cksum_full_usage "\n\n"
//usage: "Calculate the CRC32 checksums of FILEs"
//usage: "Calculate CRC32 checksum of FILEs"
#include "libbb.h"
#include "common_bufsiz.h"
/* This is a NOEXEC applet. Be very careful! */
#define IS_CRC32 (ENABLE_CRC32 && (!ENABLE_CKSUM || applet_name[1] == 'r'))
#define IS_CKSUM (ENABLE_CKSUM && (!ENABLE_CRC32 || applet_name[1] == 'k'))
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);
uint32_t *crc32_table = crc32_filltable(NULL, IS_CKSUM);
int exit_code = EXIT_SUCCESS;
#if ENABLE_DESKTOP
getopt32(argv, ""); /* coreutils 6.9 compat */
getopt32(argv, ""); /* cksum coreutils 6.9 compat */
argv += optind;
#else
argv++;
@ -51,33 +58,38 @@ int cksum_main(int argc UNUSED_PARAM, char **argv)
continue;
}
crc = 0;
crc = IS_CKSUM ? 0 : 0xffffffff;
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;
/* Checksum filesize bytes, LSB first */
if (IS_CKSUM) {
uoff_t 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);
crc = (IS_CKSUM ? crc32_block_endian1 : crc32_block_endian0)(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"),
if (IS_CKSUM)
printf((*argv ? "%u %"OFF_FMT"u %s\n" : "%u %"OFF_FMT"u\n"),
(unsigned)crc, filesize, *argv);
else
printf((*argv ? "%08x %s\n" : "%08x\n"),
(unsigned)crc, *argv);
} while (*argv && *++argv);
fflush_stdout_and_exit(exit_code);