split: let me join bikeshed painting frenzy :)

this one should be able to handle huge files.
   text    data     bss     dec     hex filename
    664       4       0     668     29c busybox.t0/coreutils/split.o
    628       0       0     628     274 busybox.t1/coreutils/split.o
split_main                                           488     525     +37
suffix_len                                             4       -      -4
next_file                                             77       -     -77
(add/remove: 0/2 grow/shrink: 1/0 up/down: 37/-81)            Total: -44 bytes

diff --git a/coreutils/split.c b/coreutils/split.c
index ca546986e859ab903274f629a683f32f91a8f55b..07eb97e0cc1c1d223b26de48e0487865e4e238b9 100644 (file)
--- a/coreutils/split.c
+++ b/coreutils/split.c
@@ -10,44 +10,43 @@
  * http://www.opengroup.org/onlinepubs/009695399/utilities/split.html
  */
 #include "busybox.h"
-static unsigned suffix_len = 2;
+
 static const struct suffix_mult split_suffices[] = {
-#if ENABLE_FEATURE_SPLIT_FANCY
        { "b", 512 },
-#endif
        { "k", 1024 },
        { "m", 1024*1024 },
-#if ENABLE_FEATURE_SPLIT_FANCY
        { "g", 1024*1024*1024 },
-#endif
        { NULL, 0 }
 };
 
 /* Increment the suffix part of the filename.
- * Returns 0 on success and 1 on error (if we are out of files)
+ * Returns NULL if we are out of filenames.
  */
-static bool next_file(char **old)
+static char *next_file(char *old, unsigned suffix_len)
 {
-       size_t end = strlen(*old);
+       size_t end = strlen(old);
        unsigned i = 1;
        char *curr;
 
        do {
-               curr = *old + end - i;
+               curr = old + end - i;
                if (*curr < 'z') {
                        *curr += 1;
                        break;
                }
                i++;
                if (i > suffix_len) {
-                       bb_error_msg("Suffices exhausted");
-                       return 1;
+                       return NULL;
                }
                *curr = 'a';
        } while (1);
-       return 0;
+
+       return old;
 }
 
+#define read_buffer bb_common_bufsiz1
+enum { READ_BUFFER_SIZE = sizeof(bb_common_bufsiz1) - 1 };
+
 #define SPLIT_OPT_l (1<<0)
 #define SPLIT_OPT_b (1<<1)
 #define SPLIT_OPT_a (1<<2)
@@ -55,79 +54,83 @@ static bool next_file(char **old)
 int split_main(int argc, char **argv);
 int split_main(int argc, char **argv)
 {
-       char *pfx, *buf, *input_file;
-       unsigned cnt = 1000, opt;
-       bool ret = EXIT_SUCCESS;
-       FILE *fp;
-       char *count_p, *sfx;
-//XXX: FIXME   opt_complementary = "+2"; /* at most 2 non-option arguments */
+       unsigned suffix_len = 2;
+       char *pfx;
+       char *count_p;
+       const char *sfx;
+       unsigned long cnt = 1000;
+       unsigned long remaining = 0;
+       unsigned opt;
+       int bytes_read, to_write;
+       char *src;
+
+       opt_complementary = "?2";
        opt = getopt32(argc, argv, "l:b:a:", &count_p, &count_p, &sfx);
 
        if (opt & SPLIT_OPT_l)
-               cnt = xatoi(count_p);
+               cnt = xatoul(count_p);
        if (opt & SPLIT_OPT_b)
                cnt = xatoul_sfx(count_p, split_suffices);
        if (opt & SPLIT_OPT_a)
-               suffix_len = xatoi(sfx);
+               suffix_len = xatou(sfx);
        argv += optind;
-       if (!*argv)
-               *--argv = (char*) "-";
-       input_file = *argv;
-       sfx = *++argv;
+       sfx = "x";
+       if (argv[0]) {
+               if (argv[1])
+                       sfx = argv[1];
+               xmove_fd(xopen(argv[0], O_RDONLY), 0);
+       } else {
+               argv[0] = (char *) bb_msg_standard_input;
+       }
 
-       if (sfx && (NAME_MAX < strlen(sfx) + suffix_len))
-                       bb_error_msg_and_die("Suffix too long");
+       if (NAME_MAX < strlen(sfx) + suffix_len)
+               bb_error_msg_and_die("suffix too long");
 
        {
-               char *char_p = xzalloc(suffix_len);
+               char *char_p = xzalloc(suffix_len + 1);
                memset(char_p, 'a', suffix_len);
-               pfx = xasprintf("%s%s", sfx ? sfx : "x", char_p);
+               pfx = xasprintf("%s%s", sfx, char_p);
                if (ENABLE_FEATURE_CLEAN_UP)
                        free(char_p);
        }
-       fp = fopen_or_warn_stdin(input_file);
-//XXX:FIXME: unify those two file-handling schemata below (FILE vs fd) !
-       if (opt & SPLIT_OPT_b) {
-               ssize_t i;
-               ssize_t bytes = 0;
-               int inp = fileno(fp);
 
+       while (1) {
+               bytes_read = safe_read(0, read_buffer, READ_BUFFER_SIZE);
+               if (!bytes_read)
+                       break;
+               if (bytes_read < 0)
+                       bb_perror_msg_and_die("%s", argv[0]);
+               src = read_buffer;
                do {
-                       int out = xopen(pfx, O_WRONLY | O_CREAT | O_TRUNC);
-                       lseek(inp, bytes, SEEK_SET);
-                       buf = xzalloc(cnt);
-                       bytes += i = full_read(inp, buf, cnt);
-                       xwrite(out, buf, i);
-                       free(buf);
-                       close(out);
-                       if (next_file(&pfx)) {
-                               ret++;
-                               goto bail;
+                       if (!remaining) {
+                               if (!pfx)
+                                       bb_error_msg_and_die("suffices exhausted");
+                               xmove_fd(xopen(pfx, O_WRONLY | O_CREAT | O_TRUNC), 1);
+                               pfx = next_file(pfx, suffix_len);
+                               remaining = cnt;
                        }
-               } while (i == cnt); /* if we read less than cnt, then nothing is left */
-       } else { /* -l */
-               do {
-                       unsigned i = cnt;
-                       int out = xopen(pfx, O_WRONLY | O_CREAT | O_TRUNC);
-                       buf = NULL;
-                       while (i--) {
-                           buf = xmalloc_fgets(fp);
-                               if (buf == NULL)
-                                       break;
-                               xwrite(out, buf, strlen(buf));
-                               free(buf);
-                       };
-                       close(out);
-                       if (next_file(&pfx)) {
-                               ret++;
-                               goto bail;
+
+                       if (opt & SPLIT_OPT_b) {
+                               /* split by bytes */
+                               to_write = (bytes_read < remaining) ? bytes_read : remaining;
+                               remaining -= to_write;
+                       } else {
+                               /* split by lines */
+                               /* can be sped up by using _memrchr_
+                                * and writing many lines at once... */
+                               char *end = memchr(src, '\n', bytes_read);
+                               if (end) {
+                                       --remaining;
+                                       to_write = end - src + 1;
+                               } else {
+                                       to_write = bytes_read;
+                               }
                        }
-               } while (buf);
-       }
-bail:
-       if (ENABLE_FEATURE_CLEAN_UP) {
-               free(pfx);
-               fclose_if_not_stdin(fp);
+
+                       xwrite(1, src, to_write);
+                       bytes_read -= to_write;
+                       src += to_write;
+               } while (bytes_read);
        }
-       return ret;
+       return 0;
 }