source: MondoRescue/branches/stable/mindi-busybox/coreutils/sort.c

/* vi: set sw=4 ts=4: */
/*
 * SuS3 compliant sort implementation for busybox
 *
 * Copyright (C) 2004 by Rob Landley <rob@landley.net>
 *
 * MAINTAINER: Rob Landley <rob@landley.net>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 *
 * See SuS3 sort standard at:
 * http://www.opengroup.org/onlinepubs/007904975/utilities/sort.html
 */

#include "libbb.h"

/* This is a NOEXEC applet. Be very careful! */


/*
    sort [-m][-o output][-bdfinru][-t char][-k keydef]... [file...]
    sort -c [-bdfinru][-t char][-k keydef][file]
*/

/* These are sort types */
static const char OPT_STR[] ALIGN1 = "ngMucszbrdfimS:T:o:k:t:";
enum {
    FLAG_n  = 1,            /* Numeric sort */
    FLAG_g  = 2,            /* Sort using strtod() */
    FLAG_M  = 4,            /* Sort date */
/* ucsz apply to root level only, not keys.  b at root level implies bb */
    FLAG_u  = 8,            /* Unique */
    FLAG_c  = 0x10,         /* Check: no output, exit(!ordered) */
    FLAG_s  = 0x20,         /* Stable sort, no ascii fallback at end */
    FLAG_z  = 0x40,         /* Input is null terminated, not \n */
/* These can be applied to search keys, the previous four can't */
    FLAG_b  = 0x80,         /* Ignore leading blanks */
    FLAG_r  = 0x100,        /* Reverse */
    FLAG_d  = 0x200,        /* Ignore !(isalnum()|isspace()) */
    FLAG_f  = 0x400,        /* Force uppercase */
    FLAG_i  = 0x800,        /* Ignore !isprint() */
    FLAG_m  = 0x1000,       /* ignored: merge already sorted files; do not sort */
    FLAG_S  = 0x2000,       /* ignored: -S, --buffer-size=SIZE */
    FLAG_T  = 0x4000,       /* ignored: -T, --temporary-directory=DIR */
    FLAG_o  = 0x8000,
    FLAG_k  = 0x10000,
    FLAG_t  = 0x20000,
    FLAG_bb = 0x80000000,   /* Ignore trailing blanks  */
};

#if ENABLE_FEATURE_SORT_BIG
static char key_separator;

static struct sort_key {
    struct sort_key *next_key;  /* linked list */
    unsigned range[4];  /* start word, start char, end word, end char */
    unsigned flags;
} *key_list;

static char *get_key(char *str, struct sort_key *key, int flags)
{
    int start = 0, end = 0, len, i, j;

    /* Special case whole string, so we don't have to make a copy */
    if (key->range[0] == 1 && !key->range[1] && !key->range[2] && !key->range[3]
     && !(flags & (FLAG_b | FLAG_d | FLAG_f | FLAG_i | FLAG_bb))
    ) {
        return str;
    }

    /* Find start of key on first pass, end on second pass */
    len = strlen(str);
    for (j = 0; j < 2; j++) {
        if (!key->range[2*j])
            end = len;
        /* Loop through fields */
        else {
            end = 0;
            for (i = 1; i < key->range[2*j] + j; i++) {
                if (key_separator) {
                    /* Skip body of key and separator */
                    while (str[end]) {
                        if (str[end++] == key_separator)
                            break;
                    }
                } else {
                    /* Skip leading blanks */
                    while (isspace(str[end]))
                        end++;
                    /* Skip body of key */
                    while (str[end]) {
                        if (isspace(str[end]))
                            break;
                        end++;
                    }
                }
            }
        }
        if (!j) start = end;
    }
    /* Strip leading whitespace if necessary */
//XXX: skip_whitespace()
    if (flags & FLAG_b)
        while (isspace(str[start])) start++;
    /* Strip trailing whitespace if necessary */
    if (flags & FLAG_bb)
        while (end > start && isspace(str[end-1])) end--;
    /* Handle offsets on start and end */
    if (key->range[3]) {
        end += key->range[3] - 1;
        if (end > len) end = len;
    }
    if (key->range[1]) {
        start += key->range[1] - 1;
        if (start > len) start = len;
    }
    /* Make the copy */
    if (end < start) end = start;
    str = xstrndup(str+start, end-start);
    /* Handle -d */
    if (flags & FLAG_d) {
        for (start = end = 0; str[end]; end++)
            if (isspace(str[end]) || isalnum(str[end]))
                str[start++] = str[end];
        str[start] = '\0';
    }
    /* Handle -i */
    if (flags & FLAG_i) {
        for (start = end = 0; str[end]; end++)
            if (isprint(str[end]))
                str[start++] = str[end];
        str[start] = '\0';
    }
    /* Handle -f */
    if (flags & FLAG_f)
        for (i = 0; str[i]; i++)
            str[i] = toupper(str[i]);

    return str;
}

static struct sort_key *add_key(void)
{
    struct sort_key **pkey = &key_list;
    while (*pkey)
        pkey = &((*pkey)->next_key);
    return *pkey = xzalloc(sizeof(struct sort_key));
}

#define GET_LINE(fp) \
    ((option_mask32 & FLAG_z) \
    ? bb_get_chunk_from_file(fp, NULL) \
    : xmalloc_getline(fp))
#else
#define GET_LINE(fp) xmalloc_getline(fp)
#endif

/* Iterate through keys list and perform comparisons */
static int compare_keys(const void *xarg, const void *yarg)
{
    int flags = option_mask32, retval = 0;
    char *x, *y;

#if ENABLE_FEATURE_SORT_BIG
    struct sort_key *key;

    for (key = key_list; !retval && key; key = key->next_key) {
        flags = key->flags ? key->flags : option_mask32;
        /* Chop out and modify key chunks, handling -dfib */
        x = get_key(*(char **)xarg, key, flags);
        y = get_key(*(char **)yarg, key, flags);
#else
    /* This curly bracket serves no purpose but to match the nesting
       level of the for () loop we're not using */
    {
        x = *(char **)xarg;
        y = *(char **)yarg;
#endif
        /* Perform actual comparison */
        switch (flags & 7) {
        default:
            bb_error_msg_and_die("unknown sort type");
            break;
        /* Ascii sort */
        case 0:
#if ENABLE_LOCALE_SUPPORT
            retval = strcoll(x, y);
#else
            retval = strcmp(x, y);
#endif
            break;
#if ENABLE_FEATURE_SORT_BIG
        case FLAG_g: {
            char *xx, *yy;
            double dx = strtod(x, &xx);
            double dy = strtod(y, &yy);
            /* not numbers < NaN < -infinity < numbers < +infinity) */
            if (x == xx)
                retval = (y == yy ? 0 : -1);
            else if (y == yy)
                retval = 1;
            /* Check for isnan */
            else if (dx != dx)
                retval = (dy != dy) ? 0 : -1;
            else if (dy != dy)
                retval = 1;
            /* Check for infinity.  Could underflow, but it avoids libm. */
            else if (1.0 / dx == 0.0) {
                if (dx < 0)
                    retval = (1.0 / dy == 0.0 && dy < 0) ? 0 : -1;
                else
                    retval = (1.0 / dy == 0.0 && dy > 0) ? 0 : 1;
            } else if (1.0 / dy == 0.0)
                retval = (dy < 0) ? 1 : -1;
            else
                retval = (dx > dy) ? 1 : ((dx < dy) ? -1 : 0);
            break;
        }
        case FLAG_M: {
            struct tm thyme;
            int dx;
            char *xx, *yy;

            xx = strptime(x, "%b", &thyme);
            dx = thyme.tm_mon;
            yy = strptime(y, "%b", &thyme);
            if (!xx)
                retval = (!yy) ? 0 : -1;
            else if (!yy)
                retval = 1;
            else
                retval = (dx == thyme.tm_mon) ? 0 : dx - thyme.tm_mon;
            break;
        }
        /* Full floating point version of -n */
        case FLAG_n: {
            double dx = atof(x);
            double dy = atof(y);
            retval = (dx > dy) ? 1 : ((dx < dy) ? -1 : 0);
            break;
        }
        } /* switch */
        /* Free key copies. */
        if (x != *(char **)xarg) free(x);
        if (y != *(char **)yarg) free(y);
        /* if (retval) break; - done by for () anyway */
#else
        /* Integer version of -n for tiny systems */
        case FLAG_n:
            retval = atoi(x) - atoi(y);
            break;
        } /* switch */
#endif
    } /* for */

    /* Perform fallback sort if necessary */
    if (!retval && !(option_mask32 & FLAG_s))
        retval = strcmp(*(char **)xarg, *(char **)yarg);

    if (flags & FLAG_r) return -retval;
    return retval;
}

#if ENABLE_FEATURE_SORT_BIG
static unsigned str2u(char **str)
{
    unsigned long lu;
    if (!isdigit((*str)[0]))
        bb_error_msg_and_die("bad field specification");
    lu = strtoul(*str, str, 10);
    if ((sizeof(long) > sizeof(int) && lu > INT_MAX) || !lu)
        bb_error_msg_and_die("bad field specification");
    return lu;
}
#endif

int sort_main(int argc, char **argv);
int sort_main(int argc, char **argv)
{
    FILE *fp, *outfile = stdout;
    char *line, **lines = NULL;
    char *str_ignored, *str_o, *str_t;
    llist_t *lst_k = NULL;
    int i, flag;
    int linecount = 0;

    xfunc_error_retval = 2;

    /* Parse command line options */
    /* -o and -t can be given at most once */
    opt_complementary = "o--o:t--t:" /* -t, -o: maximum one of each */
            "k::"; /* -k takes list */
    getopt32(argv, OPT_STR, &str_ignored, &str_ignored, &str_o, &lst_k, &str_t);
#if ENABLE_FEATURE_SORT_BIG
    if (option_mask32 & FLAG_o) outfile = xfopen(str_o, "w");
    if (option_mask32 & FLAG_t) {
        if (!str_t[0] || str_t[1])
            bb_error_msg_and_die("bad -t parameter");
        key_separator = str_t[0];
    }
    /* parse sort key */
    while (lst_k) {
        enum {
            FLAG_allowed_for_k =
                FLAG_n | /* Numeric sort */
                FLAG_g | /* Sort using strtod() */
                FLAG_M | /* Sort date */
                FLAG_b | /* Ignore leading blanks */
                FLAG_r | /* Reverse */
                FLAG_d | /* Ignore !(isalnum()|isspace()) */
                FLAG_f | /* Force uppercase */
                FLAG_i | /* Ignore !isprint() */
            0
        };
        struct sort_key *key = add_key();
        char *str_k = lst_k->data;
        const char *temp2;

        i = 0; /* i==0 before comma, 1 after (-k3,6) */
        while (*str_k) {
            /* Start of range */
            /* Cannot use bb_strtou - suffix can be a letter */
            key->range[2*i] = str2u(&str_k);
            if (*str_k == '.') {
                str_k++;
                key->range[2*i+1] = str2u(&str_k);
            }
            while (*str_k) {
                if (*str_k == ',' && !i++) {
                    str_k++;
                    break;
                } /* no else needed: fall through to syntax error
                     because comma isn't in OPT_STR */
                temp2 = strchr(OPT_STR, *str_k);
                if (!temp2)
                    bb_error_msg_and_die("unknown key option");
                flag = 1 << (temp2 - OPT_STR);
                if (flag & ~FLAG_allowed_for_k)
                    bb_error_msg_and_die("unknown sort type");
                /* b after ',' means strip _trailing_ space */
                if (i && flag == FLAG_b) flag = FLAG_bb;
                key->flags |= flag;
                str_k++;
            }
        }
        /* leaking lst_k... */
        lst_k = lst_k->link;
    }
#endif
    /* global b strips leading and trailing spaces */
    if (option_mask32 & FLAG_b) option_mask32 |= FLAG_bb;

    /* Open input files and read data */
    for (i = argv[optind] ? optind : optind-1; argv[i]; i++) {
        fp = stdin;
        if (i >= optind && NOT_LONE_DASH(argv[i]))
            fp = xfopen(argv[i], "r");
        for (;;) {
            line = GET_LINE(fp);
            if (!line) break;
            if (!(linecount & 63))
                lines = xrealloc(lines, sizeof(char *) * (linecount + 64));
            lines[linecount++] = line;
        }
        fclose(fp);
    }
#if ENABLE_FEATURE_SORT_BIG
    /* if no key, perform alphabetic sort */
    if (!key_list)
        add_key()->range[0] = 1;
    /* handle -c */
    if (option_mask32 & FLAG_c) {
        int j = (option_mask32 & FLAG_u) ? -1 : 0;
        for (i = 1; i < linecount; i++)
            if (compare_keys(&lines[i-1], &lines[i]) > j) {
                fprintf(stderr, "Check line %d\n", i);
                return 1;
            }
        return 0;
    }
#endif
    /* Perform the actual sort */
    qsort(lines, linecount, sizeof(char *), compare_keys);
    /* handle -u */
    if (option_mask32 & FLAG_u) {
        flag = 0;
        /* coreutils 6.3 drop lines for which only key is the same */
        /* -- disabling last-resort compare... */
        option_mask32 |= FLAG_s;
        for (i = 1; i < linecount; i++) {
            if (!compare_keys(&lines[flag], &lines[i]))
                free(lines[i]);
            else
                lines[++flag] = lines[i];
        }
        if (linecount) linecount = flag+1;
    }
    /* Print it */
    for (i = 0; i < linecount; i++)
        fprintf(outfile, "%s\n", lines[i]);

    fflush_stdout_and_exit(EXIT_SUCCESS);
}