* 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 tarball for details. */
-#include <stdio.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <inttypes.h>
-#include "busybox.h"
-
-int cksum_main(int argc, char **argv) {
-
- uint32_t *crc32_table = bb_crc32_filltable(1);
+#include "libbb.h"
- FILE *fp;
+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;
- long length, filesize;
+ off_t length, filesize;
int bytes_read;
- char *cp;
- RESERVE_CONFIG_BUFFER(buf, BUFSIZ);
- int inp_stdin = (argc == optind) ? 1 : 0;
-
+ int exit_code = EXIT_SUCCESS;
+ uint8_t *cp;
+
+#if ENABLE_DESKTOP
+ getopt32(argv, ""); /* coreutils 6.9 compat */
+ argv += optind;
+#else
+ argv++;
+#endif
+
do {
- fp = bb_wfopen_input((inp_stdin) ? bb_msg_standard_input : *++argv);
-
+ int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input);
+
+ if (fd < 0) {
+ exit_code = EXIT_FAILURE;
+ continue;
+ }
crc = 0;
length = 0;
-
- while ((bytes_read = fread(buf, 1, BUFSIZ, fp)) > 0) {
- cp = buf;
+
+#define read_buf bb_common_bufsiz1
+ while ((bytes_read = safe_read(fd, read_buf, sizeof(read_buf))) > 0) {
+ cp = (uint8_t *) read_buf;
length += bytes_read;
- while (bytes_read--)
- crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ (*cp++)) & 0xffL];
+ do {
+ crc = (crc << 8) ^ crc32_table[(crc >> 24) ^ *cp++];
+ } while (--bytes_read);
}
-
+ close(fd);
+
filesize = length;
-
- for (; length; length >>= 8)
- crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xffL];
- crc ^= 0xffffffffL;
-
- if (inp_stdin) {
- printf("%"PRIu32" %li\n", crc, filesize);
- break;
+
+ 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;
}
-
- printf("%"PRIu32" %li %s\n", crc, filesize, *argv);
- fclose(fp);
- } while (*(argv+1));
-
- return EXIT_SUCCESS;
+ crc = ~crc;
+
+ printf((*argv ? "%"PRIu32" %"OFF_FMT"i %s\n" : "%"PRIu32" %"OFF_FMT"i\n"),
+ crc, filesize, *argv);
+ } while (*argv && *++argv);
+
+ fflush_stdout_and_exit(exit_code);
}