source: MondoRescue/branches/stable/mindi-busybox/coreutils/ls.c@ 1770

/* vi: set sw=4 ts=4: */
/*
 * tiny-ls.c version 0.1.0: A minimalist 'ls'
 * Copyright (C) 1996 Brian Candler <B.Candler@pobox.com>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/*
 * To achieve a small memory footprint, this version of 'ls' doesn't do any
 * file sorting, and only has the most essential command line switches
 * (i.e., the ones I couldn't live without :-) All features which involve
 * linking in substantial chunks of libc can be disabled.
 *
 * Although I don't really want to add new features to this program to
 * keep it small, I *am* interested to receive bug fixes and ways to make
 * it more portable.
 *
 * KNOWN BUGS:
 * 1. ls -l of a directory doesn't give "total <blocks>" header
 * 2. ls of a symlink to a directory doesn't list directory contents
 * 3. hidden files can make column width too large
 *
 * NON-OPTIMAL BEHAVIOUR:
 * 1. autowidth reads directories twice
 * 2. if you do a short directory listing without filetype characters
 *    appended, there's no need to stat each one
 * PORTABILITY:
 * 1. requires lstat (BSD) - how do you do it without?
 */

#include <getopt.h>
#include "libbb.h"

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


enum {

TERMINAL_WIDTH  = 80,           /* use 79 if terminal has linefold bug */
COLUMN_GAP      = 2,            /* includes the file type char */

/* what is the overall style of the listing */
STYLE_COLUMNS   = 1 << 21,      /* fill columns */
STYLE_LONG      = 2 << 21,      /* one record per line, extended info */
STYLE_SINGLE    = 3 << 21,      /* one record per line */
STYLE_MASK      = STYLE_SINGLE,

/* 51306 lrwxrwxrwx  1 root     root         2 May 11 01:43 /bin/view -> vi* */
/* what file information will be listed */
LIST_INO        = 1 << 0,
LIST_BLOCKS     = 1 << 1,
LIST_MODEBITS   = 1 << 2,
LIST_NLINKS     = 1 << 3,
LIST_ID_NAME    = 1 << 4,
LIST_ID_NUMERIC = 1 << 5,
LIST_CONTEXT    = 1 << 6,
LIST_SIZE       = 1 << 7,
LIST_DEV        = 1 << 8,
LIST_DATE_TIME  = 1 << 9,
LIST_FULLTIME   = 1 << 10,
LIST_FILENAME   = 1 << 11,
LIST_SYMLINK    = 1 << 12,
LIST_FILETYPE   = 1 << 13,
LIST_EXEC       = 1 << 14,
LIST_MASK       = (LIST_EXEC << 1) - 1,

/* what files will be displayed */
DISP_DIRNAME    = 1 << 15,      /* 2 or more items? label directories */
DISP_HIDDEN     = 1 << 16,      /* show filenames starting with . */
DISP_DOT        = 1 << 17,      /* show . and .. */
DISP_NOLIST     = 1 << 18,      /* show directory as itself, not contents */
DISP_RECURSIVE  = 1 << 19,      /* show directory and everything below it */
DISP_ROWS       = 1 << 20,      /* print across rows */
DISP_MASK       = ((DISP_ROWS << 1) - 1) & ~(DISP_DIRNAME - 1),

/* how will the files be sorted (CONFIG_FEATURE_LS_SORTFILES) */
SORT_FORWARD    = 0,            /* sort in reverse order */
SORT_REVERSE    = 1 << 27,      /* sort in reverse order */

SORT_NAME       = 0,            /* sort by file name */
SORT_SIZE       = 1 << 28,      /* sort by file size */
SORT_ATIME      = 2 << 28,      /* sort by last access time */
SORT_CTIME      = 3 << 28,      /* sort by last change time */
SORT_MTIME      = 4 << 28,      /* sort by last modification time */
SORT_VERSION    = 5 << 28,      /* sort by version */
SORT_EXT        = 6 << 28,      /* sort by file name extension */
SORT_DIR        = 7 << 28,      /* sort by file or directory */
SORT_MASK       = (7 << 28) * ENABLE_FEATURE_LS_SORTFILES,

/* which of the three times will be used */
TIME_CHANGE     = (1 << 23) * ENABLE_FEATURE_LS_TIMESTAMPS,
TIME_ACCESS     = (1 << 24) * ENABLE_FEATURE_LS_TIMESTAMPS,
TIME_MASK       = (3 << 23) * ENABLE_FEATURE_LS_TIMESTAMPS,

FOLLOW_LINKS    = (1 << 25) * ENABLE_FEATURE_LS_FOLLOWLINKS,

LS_DISP_HR      = (1 << 26) * ENABLE_FEATURE_HUMAN_READABLE,

LIST_SHORT      = LIST_FILENAME,
LIST_LONG       = LIST_MODEBITS | LIST_NLINKS | LIST_ID_NAME | LIST_SIZE | \
                  LIST_DATE_TIME | LIST_FILENAME | LIST_SYMLINK,

SPLIT_DIR       = 1,
SPLIT_FILE      = 0,
SPLIT_SUBDIR    = 2,

};

#define TYPEINDEX(mode) (((mode) >> 12) & 0x0f)
#define TYPECHAR(mode)  ("0pcCd?bB-?l?s???" [TYPEINDEX(mode)])
#define APPCHAR(mode)   ("\0|\0\0/\0\0\0\0\0@\0=\0\0\0" [TYPEINDEX(mode)])
#define COLOR(mode) ("\000\043\043\043\042\000\043\043"\
             "\000\000\044\000\043\000\000\040" [TYPEINDEX(mode)])
#define ATTR(mode)  ("\00\00\01\00\01\00\01\00"\
             "\00\00\01\00\01\00\00\01" [TYPEINDEX(mode)])

/* colored LS support by JaWi, janwillem.janssen@lxtreme.nl */
#if ENABLE_FEATURE_LS_COLOR
static smallint show_color;
/* long option entry used only for --color, which has no short option
 * equivalent */
static const char ls_color_opt[] ALIGN1 =
    "color\0" Optional_argument "\xff" /* no short equivalent */
    ;
#else
enum { show_color = 0 };
#endif

/*
 * a directory entry and its stat info are stored here
 */
struct dnode {                  /* the basic node */
    const char *name;             /* the dir entry name */
    const char *fullname;         /* the dir entry name */
    int   allocated;
    struct stat dstat;      /* the file stat info */
    USE_SELINUX(security_context_t sid;)
    struct dnode *next;     /* point at the next node */
};
typedef struct dnode dnode_t;

static struct dnode **list_dir(const char *);
static struct dnode **dnalloc(int);
static int list_single(struct dnode *);

static unsigned all_fmt;

#if ENABLE_FEATURE_AUTOWIDTH
static unsigned tabstops = COLUMN_GAP;
static unsigned terminal_width = TERMINAL_WIDTH;
#else
enum {
    tabstops = COLUMN_GAP,
    terminal_width = TERMINAL_WIDTH,
};
#endif

static int status = EXIT_SUCCESS;

static struct dnode *my_stat(const char *fullname, const char *name, int force_follow)
{
    struct stat dstat;
    struct dnode *cur;
    USE_SELINUX(security_context_t sid = NULL;)

    if ((all_fmt & FOLLOW_LINKS) || force_follow) {
#if ENABLE_SELINUX
        if (is_selinux_enabled())  {
             getfilecon(fullname, &sid);
        }
#endif
        if (stat(fullname, &dstat)) {
            bb_perror_msg("%s", fullname);
            status = EXIT_FAILURE;
            return 0;
        }
    } else {
#if ENABLE_SELINUX
        if (is_selinux_enabled()) {
            lgetfilecon(fullname, &sid);
        }
#endif
        if (lstat(fullname, &dstat)) {
            bb_perror_msg("%s", fullname);
            status = EXIT_FAILURE;
            return 0;
        }
    }

    cur = xmalloc(sizeof(struct dnode));
    cur->fullname = fullname;
    cur->name = name;
    cur->dstat = dstat;
    USE_SELINUX(cur->sid = sid;)
    return cur;
}

#if ENABLE_FEATURE_LS_COLOR
static char fgcolor(mode_t mode)
{
    /* Check wheter the file is existing (if so, color it red!) */
    if (errno == ENOENT)
        return '\037';
    if (S_ISREG(mode) && (mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
        return COLOR(0xF000);   /* File is executable ... */
    return COLOR(mode);
}

static char bgcolor(mode_t mode)
{
    if (S_ISREG(mode) && (mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
        return ATTR(0xF000);    /* File is executable ... */
    return ATTR(mode);
}
#endif

#if ENABLE_FEATURE_LS_FILETYPES || ENABLE_FEATURE_LS_COLOR
static char append_char(mode_t mode)
{
    if (!(all_fmt & LIST_FILETYPE))
        return '\0';
    if (S_ISDIR(mode))
        return '/';
    if (!(all_fmt & LIST_EXEC))
        return '\0';
    if (S_ISREG(mode) && (mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
        return '*';
    return APPCHAR(mode);
}
#endif

#define countdirs(A, B) count_dirs((A), (B), 1)
#define countsubdirs(A, B) count_dirs((A), (B), 0)
static int count_dirs(struct dnode **dn, int nfiles, int notsubdirs)
{
    int i, dirs;

    if (!dn)
        return 0;
    dirs = 0;
    for (i = 0; i < nfiles; i++) {
        const char *name;
        if (!S_ISDIR(dn[i]->dstat.st_mode))
            continue;
        name = dn[i]->name;
        if (notsubdirs
         || name[0]!='.' || (name[1] && (name[1]!='.' || name[2]))
        ) {
            dirs++;
        }
    }
    return dirs;
}

static int countfiles(struct dnode **dnp)
{
    int nfiles;
    struct dnode *cur;

    if (dnp == NULL)
        return 0;
    nfiles = 0;
    for (cur = dnp[0]; cur->next; cur = cur->next)
        nfiles++;
    nfiles++;
    return nfiles;
}

/* get memory to hold an array of pointers */
static struct dnode **dnalloc(int num)
{
    if (num < 1)
        return NULL;

    return xzalloc(num * sizeof(struct dnode *));
}

#if ENABLE_FEATURE_LS_RECURSIVE
static void dfree(struct dnode **dnp, int nfiles)
{
    int i;

    if (dnp == NULL)
        return;

    for (i = 0; i < nfiles; i++) {
        struct dnode *cur = dnp[i];
        if (cur->allocated)
            free((char*)cur->fullname); /* free the filename */
        free(cur);      /* free the dnode */
    }
    free(dnp);          /* free the array holding the dnode pointers */
}
#else
#define dfree(...) ((void)0)
#endif

static struct dnode **splitdnarray(struct dnode **dn, int nfiles, int which)
{
    int dncnt, i, d;
    struct dnode **dnp;

    if (dn == NULL || nfiles < 1)
        return NULL;

    /* count how many dirs and regular files there are */
    if (which == SPLIT_SUBDIR)
        dncnt = countsubdirs(dn, nfiles);
    else {
        dncnt = countdirs(dn, nfiles);  /* assume we are looking for dirs */
        if (which == SPLIT_FILE)
            dncnt = nfiles - dncnt; /* looking for files */
    }

    /* allocate a file array and a dir array */
    dnp = dnalloc(dncnt);

    /* copy the entrys into the file or dir array */
    for (d = i = 0; i < nfiles; i++) {
        if (S_ISDIR(dn[i]->dstat.st_mode)) {
            const char *name;
            if (!(which & (SPLIT_DIR|SPLIT_SUBDIR)))
                continue;
            name = dn[i]->name;
            if ((which & SPLIT_DIR)
             || name[0]!='.' || (name[1] && (name[1]!='.' || name[2]))
            ) {
                dnp[d++] = dn[i];
            }
        } else if (!(which & (SPLIT_DIR|SPLIT_SUBDIR))) {
            dnp[d++] = dn[i];
        }
    }
    return dnp;
}

#if ENABLE_FEATURE_LS_SORTFILES
static int sortcmp(const void *a, const void *b)
{
    struct dnode *d1 = *(struct dnode **)a;
    struct dnode *d2 = *(struct dnode **)b;
    unsigned sort_opts = all_fmt & SORT_MASK;
    int dif;

    dif = 0; /* assume SORT_NAME */
    // TODO: use pre-initialized function pointer
    // instead of branch forest
    if (sort_opts == SORT_SIZE) {
        dif = (int) (d2->dstat.st_size - d1->dstat.st_size);
    } else if (sort_opts == SORT_ATIME) {
        dif = (int) (d2->dstat.st_atime - d1->dstat.st_atime);
    } else if (sort_opts == SORT_CTIME) {
        dif = (int) (d2->dstat.st_ctime - d1->dstat.st_ctime);
    } else if (sort_opts == SORT_MTIME) {
        dif = (int) (d2->dstat.st_mtime - d1->dstat.st_mtime);
    } else if (sort_opts == SORT_DIR) {
        dif = S_ISDIR(d2->dstat.st_mode) - S_ISDIR(d1->dstat.st_mode);
        /* } else if (sort_opts == SORT_VERSION) { */
        /* } else if (sort_opts == SORT_EXT) { */
    }

    if (dif == 0) {
        /* sort by name - may be a tie_breaker for time or size cmp */
        if (ENABLE_LOCALE_SUPPORT) dif = strcoll(d1->name, d2->name);
        else dif = strcmp(d1->name, d2->name);
    }

    if (all_fmt & SORT_REVERSE) {
        dif = -dif;
    }
    return dif;
}

static void dnsort(struct dnode **dn, int size)
{
    qsort(dn, size, sizeof(*dn), sortcmp);
}
#else
#define dnsort(dn, size) ((void)0)
#endif


static void showfiles(struct dnode **dn, int nfiles)
{
    int i, ncols, nrows, row, nc;
    int column = 0;
    int nexttab = 0;
    int column_width = 0; /* for STYLE_LONG and STYLE_SINGLE not used */

    if (dn == NULL || nfiles < 1)
        return;

    if (all_fmt & STYLE_LONG) {
        ncols = 1;
    } else {
        /* find the longest file name, use that as the column width */
        for (i = 0; i < nfiles; i++) {
            int len = strlen(dn[i]->name);
            if (column_width < len)
                column_width = len;
        }
        column_width += tabstops +
            USE_SELINUX( ((all_fmt & LIST_CONTEXT) ? 33 : 0) + )
                         ((all_fmt & LIST_INO) ? 8 : 0) +
                         ((all_fmt & LIST_BLOCKS) ? 5 : 0);
        ncols = (int) (terminal_width / column_width);
    }

    if (ncols > 1) {
        nrows = nfiles / ncols;
        if (nrows * ncols < nfiles)
            nrows++;                /* round up fractionals */
    } else {
        nrows = nfiles;
        ncols = 1;
    }

    for (row = 0; row < nrows; row++) {
        for (nc = 0; nc < ncols; nc++) {
            /* reach into the array based on the column and row */
            i = (nc * nrows) + row; /* assume display by column */
            if (all_fmt & DISP_ROWS)
                i = (row * ncols) + nc; /* display across row */
            if (i < nfiles) {
                if (column > 0) {
                    nexttab -= column;
                    printf("%*s", nexttab, "");
                    column += nexttab;
                }
                nexttab = column + column_width;
                column += list_single(dn[i]);
            }
        }
        putchar('\n');
        column = 0;
    }
}


static void showdirs(struct dnode **dn, int ndirs, int first)
{
    int i, nfiles;
    struct dnode **subdnp;
    int dndirs;
    struct dnode **dnd;

    if (dn == NULL || ndirs < 1)
        return;

    for (i = 0; i < ndirs; i++) {
        if (all_fmt & (DISP_DIRNAME | DISP_RECURSIVE)) {
            if (!first)
                puts("");
            first = 0;
            printf("%s:\n", dn[i]->fullname);
        }
        subdnp = list_dir(dn[i]->fullname);
        nfiles = countfiles(subdnp);
        if (nfiles > 0) {
            /* list all files at this level */
            dnsort(subdnp, nfiles);
            showfiles(subdnp, nfiles);
            if (ENABLE_FEATURE_LS_RECURSIVE) {
                if (all_fmt & DISP_RECURSIVE) {
                    /* recursive- list the sub-dirs */
                    dnd = splitdnarray(subdnp, nfiles, SPLIT_SUBDIR);
                    dndirs = countsubdirs(subdnp, nfiles);
                    if (dndirs > 0) {
                        dnsort(dnd, dndirs);
                        showdirs(dnd, dndirs, 0);
                        /* free the array of dnode pointers to the dirs */
                        free(dnd);
                    }
                }
                /* free the dnodes and the fullname mem */
                dfree(subdnp, nfiles);
            }
        }
    }
}


static struct dnode **list_dir(const char *path)
{
    struct dnode *dn, *cur, **dnp;
    struct dirent *entry;
    DIR *dir;
    int i, nfiles;

    if (path == NULL)
        return NULL;

    dn = NULL;
    nfiles = 0;
    dir = warn_opendir(path);
    if (dir == NULL) {
        status = EXIT_FAILURE;
        return NULL;    /* could not open the dir */
    }
    while ((entry = readdir(dir)) != NULL) {
        char *fullname;

        /* are we going to list the file- it may be . or .. or a hidden file */
        if (entry->d_name[0] == '.') {
            if ((!entry->d_name[1] || (entry->d_name[1] == '.' && !entry->d_name[2]))
             && !(all_fmt & DISP_DOT)
            ) {
                continue;
            }
            if (!(all_fmt & DISP_HIDDEN))
                continue;
        }
        fullname = concat_path_file(path, entry->d_name);
        cur = my_stat(fullname, bb_basename(fullname), 0);
        if (!cur) {
            free(fullname);
            continue;
        }
        cur->allocated = 1;
        cur->next = dn;
        dn = cur;
        nfiles++;
    }
    closedir(dir);

    /* now that we know how many files there are
     * allocate memory for an array to hold dnode pointers
     */
    if (dn == NULL)
        return NULL;
    dnp = dnalloc(nfiles);
    for (i = 0, cur = dn; i < nfiles; i++) {
        dnp[i] = cur;   /* save pointer to node in array */
        cur = cur->next;
    }

    return dnp;
}


#if ENABLE_FEATURE_LS_TIMESTAMPS
/* Do time() just once. Saves one syscall per file for "ls -l" */
/* Initialized in main() */
static time_t current_time_t;
#endif

static int list_single(struct dnode *dn)
{
    int i, column = 0;

#if ENABLE_FEATURE_LS_TIMESTAMPS
    char *filetime;
    time_t ttime, age;
#endif
#if ENABLE_FEATURE_LS_FILETYPES || ENABLE_FEATURE_LS_COLOR
    struct stat info;
    char append;
#endif

    if (dn->fullname == NULL)
        return 0;

#if ENABLE_FEATURE_LS_TIMESTAMPS
    ttime = dn->dstat.st_mtime; /* the default time */
    if (all_fmt & TIME_ACCESS)
        ttime = dn->dstat.st_atime;
    if (all_fmt & TIME_CHANGE)
        ttime = dn->dstat.st_ctime;
    filetime = ctime(&ttime);
#endif
#if ENABLE_FEATURE_LS_FILETYPES
    append = append_char(dn->dstat.st_mode);
#endif

    for (i = 0; i <= 31; i++) {
        switch (all_fmt & (1 << i)) {
        case LIST_INO:
            column += printf("%7ld ", (long) dn->dstat.st_ino);
            break;
        case LIST_BLOCKS:
            column += printf("%4"OFF_FMT"d ", (off_t) dn->dstat.st_blocks >> 1);
            break;
        case LIST_MODEBITS:
            column += printf("%-10s ", (char *) bb_mode_string(dn->dstat.st_mode));
            break;
        case LIST_NLINKS:
            column += printf("%4ld ", (long) dn->dstat.st_nlink);
            break;
        case LIST_ID_NAME:
#if ENABLE_FEATURE_LS_USERNAME
            printf("%-8.8s %-8.8s",
                get_cached_username(dn->dstat.st_uid),
                get_cached_groupname(dn->dstat.st_gid));
            column += 17;
            break;
#endif
        case LIST_ID_NUMERIC:
            column += printf("%-8d %-8d", dn->dstat.st_uid, dn->dstat.st_gid);
            break;
        case LIST_SIZE:
        case LIST_DEV:
            if (S_ISBLK(dn->dstat.st_mode) || S_ISCHR(dn->dstat.st_mode)) {
                column += printf("%4d, %3d ", (int) major(dn->dstat.st_rdev),
                       (int) minor(dn->dstat.st_rdev));
            } else {
                if (all_fmt & LS_DISP_HR) {
                    column += printf("%9s ",
                        make_human_readable_str(dn->dstat.st_size, 1, 0));
                } else {
                    column += printf("%9"OFF_FMT"d ", (off_t) dn->dstat.st_size);
                }
            }
            break;
#if ENABLE_FEATURE_LS_TIMESTAMPS
        case LIST_FULLTIME:
            printf("%24.24s ", filetime);
            column += 25;
            break;
        case LIST_DATE_TIME:
            if ((all_fmt & LIST_FULLTIME) == 0) {
                /* current_time_t ~== time(NULL) */
                age = current_time_t - ttime;
                printf("%6.6s ", filetime + 4);
                if (age < 3600L * 24 * 365 / 2 && age > -15 * 60) {
                    /* hh:mm if less than 6 months old */
                    printf("%5.5s ", filetime + 11);
                } else {
                    printf(" %4.4s ", filetime + 20);
                }
                column += 13;
            }
            break;
#endif
#if ENABLE_SELINUX
        case LIST_CONTEXT:
            {
                char context[80];
                int len = 0;

                if (dn->sid) {
                    /* I assume sid initilized with NULL */
                    len = strlen(dn->sid) + 1;
                    safe_strncpy(context, dn->sid, len);
                    freecon(dn->sid);
                } else {
                    safe_strncpy(context, "unknown", 8);
                }
                printf("%-32s ", context);
                column += MAX(33, len);
            }
            break;
#endif
        case LIST_FILENAME:
            errno = 0;
#if ENABLE_FEATURE_LS_COLOR
            if (show_color && !lstat(dn->fullname, &info)) {
                printf("\033[%d;%dm", bgcolor(info.st_mode),
                        fgcolor(info.st_mode));
            }
#endif
            column += printf("%s", dn->name);
            if (show_color) {
                printf("\033[0m");
            }
            break;
        case LIST_SYMLINK:
            if (S_ISLNK(dn->dstat.st_mode)) {
                char *lpath = xmalloc_readlink_or_warn(dn->fullname);
                if (!lpath) break;
                printf(" -> ");
#if ENABLE_FEATURE_LS_FILETYPES || ENABLE_FEATURE_LS_COLOR
                if (!stat(dn->fullname, &info)) {
                    append = append_char(info.st_mode);
                }
#endif
#if ENABLE_FEATURE_LS_COLOR
                if (show_color) {
                    errno = 0;
                    printf("\033[%d;%dm", bgcolor(info.st_mode),
                           fgcolor(info.st_mode));
                }
#endif
                column += printf("%s", lpath) + 4;
                if (show_color) {
                    printf("\033[0m");
                }
                free(lpath);
            }
            break;
#if ENABLE_FEATURE_LS_FILETYPES
        case LIST_FILETYPE:
            if (append) {
                putchar(append);
                column++;
            }
            break;
#endif
        }
    }

    return column;
}

/* "[-]Cadil1", POSIX mandated options, busybox always supports */
/* "[-]gnsx", POSIX non-mandated options, busybox always supports */
/* "[-]Ak" GNU options, busybox always supports */
/* "[-]FLRctur", POSIX mandated options, busybox optionally supports */
/* "[-]p", POSIX non-mandated options, busybox optionally supports */
/* "[-]SXvThw", GNU options, busybox optionally supports */
/* "[-]K", SELinux mandated options, busybox optionally supports */
/* "[-]e", I think we made this one up */
static const char ls_options[] ALIGN1 =
    "Cadil1gnsxAk"
    USE_FEATURE_LS_TIMESTAMPS("cetu")
    USE_FEATURE_LS_SORTFILES("SXrv")
    USE_FEATURE_LS_FILETYPES("Fp")
    USE_FEATURE_LS_FOLLOWLINKS("L")
    USE_FEATURE_LS_RECURSIVE("R")
    USE_FEATURE_HUMAN_READABLE("h")
    USE_SELINUX("K")
    USE_FEATURE_AUTOWIDTH("T:w:")
    USE_SELINUX("Z");

enum {
    LIST_MASK_TRIGGER   = 0,
    STYLE_MASK_TRIGGER  = STYLE_MASK,
    DISP_MASK_TRIGGER   = DISP_ROWS,
    SORT_MASK_TRIGGER   = SORT_MASK,
};

static const unsigned opt_flags[] = {
    LIST_SHORT | STYLE_COLUMNS, /* C */
    DISP_HIDDEN | DISP_DOT,     /* a */
    DISP_NOLIST,                /* d */
    LIST_INO,                   /* i */
    LIST_LONG | STYLE_LONG,     /* l - remember LS_DISP_HR in mask! */
    LIST_SHORT | STYLE_SINGLE,  /* 1 */
    0,                          /* g - ingored */
    LIST_ID_NUMERIC,            /* n */
    LIST_BLOCKS,                /* s */
    DISP_ROWS,                  /* x */
    DISP_HIDDEN,                /* A */
    ENABLE_SELINUX * LIST_CONTEXT, /* k (ignored if !SELINUX) */
#if ENABLE_FEATURE_LS_TIMESTAMPS
    TIME_CHANGE | (ENABLE_FEATURE_LS_SORTFILES * SORT_CTIME),   /* c */
    LIST_FULLTIME,              /* e */
    ENABLE_FEATURE_LS_SORTFILES * SORT_MTIME,   /* t */
    TIME_ACCESS | (ENABLE_FEATURE_LS_SORTFILES * SORT_ATIME),   /* u */
#endif
#if ENABLE_FEATURE_LS_SORTFILES
    SORT_SIZE,                  /* S */
    SORT_EXT,                   /* X */
    SORT_REVERSE,               /* r */
    SORT_VERSION,               /* v */
#endif
#if ENABLE_FEATURE_LS_FILETYPES
    LIST_FILETYPE | LIST_EXEC,  /* F */
    LIST_FILETYPE,              /* p */
#endif
#if ENABLE_FEATURE_LS_FOLLOWLINKS
    FOLLOW_LINKS,               /* L */
#endif
#if ENABLE_FEATURE_LS_RECURSIVE
    DISP_RECURSIVE,             /* R */
#endif
#if ENABLE_FEATURE_HUMAN_READABLE
    LS_DISP_HR,                 /* h */
#endif
#if ENABLE_SELINUX
    LIST_MODEBITS|LIST_NLINKS|LIST_CONTEXT|LIST_SIZE|LIST_DATE_TIME, /* K */
#endif
#if ENABLE_FEATURE_AUTOWIDTH
    0, 0,                       /* T, w - ignored */
#endif
#if ENABLE_SELINUX
    LIST_MODEBITS|LIST_ID_NAME|LIST_CONTEXT, /* Z */
#endif
    (1U<<31)
};


/* THIS IS A "SAFE" APPLET, main() MAY BE CALLED INTERNALLY FROM SHELL */
/* BE CAREFUL! */

int ls_main(int argc, char **argv);
int ls_main(int argc, char **argv)
{
    struct dnode **dnd;
    struct dnode **dnf;
    struct dnode **dnp;
    struct dnode *dn;
    struct dnode *cur;
    unsigned opt;
    int nfiles = 0;
    int dnfiles;
    int dndirs;
    int oi;
    int ac;
    int i;
    char **av;
    USE_FEATURE_AUTOWIDTH(char *tabstops_str = NULL;)
    USE_FEATURE_AUTOWIDTH(char *terminal_width_str = NULL;)
    USE_FEATURE_LS_COLOR(char *color_opt;)

#if ENABLE_FEATURE_LS_TIMESTAMPS
    time(&current_time_t);
#endif

    all_fmt = LIST_SHORT |
        (ENABLE_FEATURE_LS_SORTFILES * (SORT_NAME | SORT_FORWARD));

#if ENABLE_FEATURE_AUTOWIDTH
    /* Obtain the terminal width */
    get_terminal_width_height(STDIN_FILENO, &terminal_width, NULL);
    /* Go one less... */
    terminal_width--;
#endif

    /* process options */
    USE_FEATURE_LS_COLOR(applet_long_options = ls_color_opt;)
#if ENABLE_FEATURE_AUTOWIDTH
    opt = getopt32(argv, ls_options, &tabstops_str, &terminal_width_str
                USE_FEATURE_LS_COLOR(, &color_opt));
    if (tabstops_str)
        tabstops = xatou(tabstops_str);
    if (terminal_width_str)
        terminal_width = xatou(terminal_width_str);
#else
    opt = getopt32(argv, ls_options USE_FEATURE_LS_COLOR(, &color_opt));
#endif
    for (i = 0; opt_flags[i] != (1U<<31); i++) {
        if (opt & (1 << i)) {
            unsigned flags = opt_flags[i];

            if (flags & LIST_MASK_TRIGGER)
                all_fmt &= ~LIST_MASK;
            if (flags & STYLE_MASK_TRIGGER)
                all_fmt &= ~STYLE_MASK;
            if (flags & SORT_MASK_TRIGGER)
                all_fmt &= ~SORT_MASK;
            if (flags & DISP_MASK_TRIGGER)
                all_fmt &= ~DISP_MASK;
            if (flags & TIME_MASK)
                all_fmt &= ~TIME_MASK;
            if (flags & LIST_CONTEXT)
                all_fmt |= STYLE_SINGLE;
            /* huh?? opt cannot be 'l' */
            //if (LS_DISP_HR && opt == 'l')
            //  all_fmt &= ~LS_DISP_HR;
            all_fmt |= flags;
        }
    }

#if ENABLE_FEATURE_LS_COLOR
    /* find color bit value - last position for short getopt */
    if (ENABLE_FEATURE_LS_COLOR_IS_DEFAULT && isatty(STDOUT_FILENO)) {
        char *p = getenv("LS_COLORS");
        /* LS_COLORS is unset, or (not empty && not "none") ? */
        if (!p || (p[0] && strcmp(p, "none")))
            show_color = 1;
    }
    if (opt & (1 << i)) {  /* next flag after short options */
        if (!color_opt || !strcmp("always", color_opt))
            show_color = 1;
        else if (color_opt && !strcmp("never", color_opt))
            show_color = 0;
        else if (color_opt && !strcmp("auto", color_opt) && isatty(STDOUT_FILENO))
            show_color = 1;
    }
#endif

    /* sort out which command line options take precedence */
    if (ENABLE_FEATURE_LS_RECURSIVE && (all_fmt & DISP_NOLIST))
        all_fmt &= ~DISP_RECURSIVE; /* no recurse if listing only dir */
    if (ENABLE_FEATURE_LS_TIMESTAMPS && ENABLE_FEATURE_LS_SORTFILES) {
        if (all_fmt & TIME_CHANGE)
            all_fmt = (all_fmt & ~SORT_MASK) | SORT_CTIME;
        if (all_fmt & TIME_ACCESS)
            all_fmt = (all_fmt & ~SORT_MASK) | SORT_ATIME;
    }
    if ((all_fmt & STYLE_MASK) != STYLE_LONG) /* only for long list */
        all_fmt &= ~(LIST_ID_NUMERIC|LIST_FULLTIME|LIST_ID_NAME|LIST_ID_NUMERIC);
    if (ENABLE_FEATURE_LS_USERNAME)
        if ((all_fmt & STYLE_MASK) == STYLE_LONG && (all_fmt & LIST_ID_NUMERIC))
            all_fmt &= ~LIST_ID_NAME; /* don't list names if numeric uid */

    /* choose a display format */
    if (!(all_fmt & STYLE_MASK))
        all_fmt |= (isatty(STDOUT_FILENO) ? STYLE_COLUMNS : STYLE_SINGLE);

    /*
     * when there are no cmd line args we have to supply a default "." arg.
     * we will create a second argv array, "av" that will hold either
     * our created "." arg, or the real cmd line args.  The av array
     * just holds the pointers- we don't move the date the pointers
     * point to.
     */
    ac = argc - optind; /* how many cmd line args are left */
    if (ac < 1) {
        static const char *const dotdir[] = { "." };

        av = (char **) dotdir;
        ac = 1;
    } else {
        av = argv + optind;
    }

    /* now, everything is in the av array */
    if (ac > 1)
        all_fmt |= DISP_DIRNAME;    /* 2 or more items? label directories */

    /* stuff the command line file names into a dnode array */
    dn = NULL;
    for (oi = 0; oi < ac; oi++) {
        /* ls w/o -l follows links on command line */
        cur = my_stat(av[oi], av[oi], !(all_fmt & STYLE_LONG));
        if (!cur)
            continue;
        cur->allocated = 0;
        cur->next = dn;
        dn = cur;
        nfiles++;
    }

    /* now that we know how many files there are
     * allocate memory for an array to hold dnode pointers
     */
    dnp = dnalloc(nfiles);
    for (i = 0, cur = dn; i < nfiles; i++) {
        dnp[i] = cur;   /* save pointer to node in array */
        cur = cur->next;
    }

    if (all_fmt & DISP_NOLIST) {
        dnsort(dnp, nfiles);
        if (nfiles > 0)
            showfiles(dnp, nfiles);
    } else {
        dnd = splitdnarray(dnp, nfiles, SPLIT_DIR);
        dnf = splitdnarray(dnp, nfiles, SPLIT_FILE);
        dndirs = countdirs(dnp, nfiles);
        dnfiles = nfiles - dndirs;
        if (dnfiles > 0) {
            dnsort(dnf, dnfiles);
            showfiles(dnf, dnfiles);
            if (ENABLE_FEATURE_CLEAN_UP)
                free(dnf);
        }
        if (dndirs > 0) {
            dnsort(dnd, dndirs);
            showdirs(dnd, dndirs, dnfiles == 0);
            if (ENABLE_FEATURE_CLEAN_UP)
                free(dnd);
        }
    }
    if (ENABLE_FEATURE_CLEAN_UP)
        dfree(dnp, nfiles);
    return status;
}