source: MondoRescue/branches/3.3/mindi-busybox/coreutils/split.c@ 3906

/* vi: set sw=4 ts=4: */
/*
 * split - split a file into pieces
 * Copyright (c) 2007 Bernhard Reutner-Fischer
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
/* BB_AUDIT: SUSv3 compliant
 * SUSv3 requirements:
 * http://www.opengroup.org/onlinepubs/009695399/utilities/split.html
 */

//usage:#define split_trivial_usage
//usage:       "[OPTIONS] [INPUT [PREFIX]]"
//usage:#define split_full_usage "\n\n"
//usage:       "    -b N[k|m]   Split by N (kilo|mega)bytes"
//usage:     "\n    -l N        Split by N lines"
//usage:     "\n    -a N        Use N letters as suffix"
//usage:
//usage:#define split_example_usage
//usage:       "$ split TODO foo\n"
//usage:       "$ cat TODO | split -a 2 -l 2 TODO_\n"

#include "libbb.h"
#include "common_bufsiz.h"

#if ENABLE_FEATURE_SPLIT_FANCY
static const struct suffix_mult split_suffixes[] = {
    { "b", 512 },
    { "k", 1024 },
    { "m", 1024*1024 },
    { "g", 1024*1024*1024 },
    { "", 0 }
};
#endif

/* Increment the suffix part of the filename.
 * Returns NULL if we are out of filenames.
 */
static char *next_file(char *old, unsigned suffix_len)
{
    size_t end = strlen(old);
    unsigned i = 1;
    char *curr;

    while (1) {
        curr = old + end - i;
        if (*curr < 'z') {
            *curr += 1;
            break;
        }
        i++;
        if (i > suffix_len) {
            return NULL;
        }
        *curr = 'a';
    }

    return old;
}

#define read_buffer bb_common_bufsiz1
enum { READ_BUFFER_SIZE = COMMON_BUFSIZE - 1 };

#define SPLIT_OPT_l (1<<0)
#define SPLIT_OPT_b (1<<1)
#define SPLIT_OPT_a (1<<2)

int split_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int split_main(int argc UNUSED_PARAM, char **argv)
{
    unsigned suffix_len = 2;
    char *pfx;
    char *count_p;
    const char *sfx;
    off_t cnt = 1000;
    off_t remaining = 0;
    unsigned opt;
    ssize_t bytes_read, to_write;
    char *src;

    setup_common_bufsiz();

    opt_complementary = "?2:a+"; /* max 2 args; -a N */
    opt = getopt32(argv, "l:b:a:", &count_p, &count_p, &suffix_len);

    if (opt & SPLIT_OPT_l)
        cnt = XATOOFF(count_p);
    if (opt & SPLIT_OPT_b) // FIXME: also needs XATOOFF
        cnt = xatoull_sfx(count_p,
                IF_FEATURE_SPLIT_FANCY(split_suffixes)
                IF_NOT_FEATURE_SPLIT_FANCY(km_suffixes)
        );
    sfx = "x";

    argv += optind;
    if (argv[0]) {
        int fd;
        if (argv[1])
            sfx = argv[1];
        fd = xopen_stdin(argv[0]);
        xmove_fd(fd, STDIN_FILENO);
    } else {
        argv[0] = (char *) bb_msg_standard_input;
    }

    if (NAME_MAX < strlen(sfx) + suffix_len)
        bb_error_msg_and_die("suffix too long");

    {
        char *char_p = xzalloc(suffix_len + 1);
        memset(char_p, 'a', suffix_len);
        pfx = xasprintf("%s%s", sfx, char_p);
        if (ENABLE_FEATURE_CLEAN_UP)
            free(char_p);
    }

    while (1) {
        bytes_read = safe_read(STDIN_FILENO, read_buffer, READ_BUFFER_SIZE);
        if (!bytes_read)
            break;
        if (bytes_read < 0)
            bb_simple_perror_msg_and_die(argv[0]);
        src = read_buffer;
        do {
            if (!remaining) {
                if (!pfx)
                    bb_error_msg_and_die("suffixes exhausted");
                xmove_fd(xopen(pfx, O_WRONLY | O_CREAT | O_TRUNC), 1);
                pfx = next_file(pfx, suffix_len);
                remaining = cnt;
            }

            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;
                }
            }

            xwrite(STDOUT_FILENO, src, to_write);
            bytes_read -= to_write;
            src += to_write;
        } while (bytes_read);
    }
    return EXIT_SUCCESS;
}