cksum: code shrink

function                                             old     new   delta
cksum_main                                           281     262     -19

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/coreutils/cksum.c b/coreutils/cksum.c
index 059a333108782e570493ac52262236b4dc418b11..e46e249f29588c48fd4aba3e5bcff65c3057cae8 100644 (file)
--- 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);