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authorDenys Vlasenko2018-02-01 11:44:52 +0100
committerDenys Vlasenko2018-02-01 11:44:52 +0100
commitda49e7057a6efada17ba43d046770c95d0bd71a6 (patch)
treec9003fe6855b305c010764edb41770502d4c195d
parentddacb03e875dd4c1a79421d030da9cdc4f081e6e (diff)
downloadbusybox-da49e7057a6efada17ba43d046770c95d0bd71a6.zip
busybox-da49e7057a6efada17ba43d046770c95d0bd71a6.tar.gz
cksum: code shrink
function old new delta cksum_main 281 262 -19 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--coreutils/cksum.c47
1 files changed, 24 insertions, 23 deletions
diff --git a/coreutils/cksum.c b/coreutils/cksum.c
index 059a333..e46e249 100644
--- a/coreutils/cksum.c
+++ b/coreutils/cksum.c
@@ -31,9 +31,6 @@ 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 crc;
- off_t length, filesize;
- int bytes_read;
int exit_code = EXIT_SUCCESS;
#if ENABLE_DESKTOP
@@ -45,38 +42,42 @@ int cksum_main(int argc UNUSED_PARAM, char **argv)
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;
- length = 0;
+ crc = 0;
+ filesize = 0;
#define read_buf bb_common_bufsiz1
- while ((bytes_read = safe_read(fd, read_buf, COMMON_BUFSIZE)) > 0) {
- length += bytes_read;
+ 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;
}
- close(fd);
-
- filesize = length;
- while (length) {
- crc = (crc << 8) ^ crc32_table[(uint8_t)(crc >> 24) ^ (uint8_t)length];
- /* must ensure that shift is unsigned! */
- if (sizeof(length) <= sizeof(unsigned))
- length = (unsigned)length >> 8;
- else if (sizeof(length) <= sizeof(unsigned long))
- length = (unsigned long)length >> 8;
- else
- length = (unsigned long long)length >> 8;
- }
crc = ~crc;
-
- printf((*argv ? "%"PRIu32" %"OFF_FMT"i %s\n" : "%"PRIu32" %"OFF_FMT"i\n"),
- crc, filesize, *argv);
+ 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);