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[coreutils.git] / src / ls.c

/* `dir', `vdir' and `ls' directory listing programs for GNU.
   Copyright (C) 85, 88, 90, 91, 1995-2003 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* If ls_mode is LS_MULTI_COL,
   the multi-column format is the default regardless
   of the type of output device.
   This is for the `dir' program.

   If ls_mode is LS_LONG_FORMAT,
   the long format is the default regardless of the
   type of output device.
   This is for the `vdir' program.

   If ls_mode is LS_LS,
   the output format depends on whether the output
   device is a terminal.
   This is for the `ls' program. */

/* Written by Richard Stallman and David MacKenzie.  */

/* Color support by Peter Anvin <Peter.Anvin@linux.org> and Dennis
   Flaherty <dennisf@denix.elk.miles.com> based on original patches by
   Greg Lee <lee@uhunix.uhcc.hawaii.edu>.  */

#include <config.h>
#include <sys/types.h>

#if HAVE_TERMIOS_H
# include <termios.h>
#endif

#ifdef GWINSZ_IN_SYS_IOCTL
# include <sys/ioctl.h>
#endif

#ifdef WINSIZE_IN_PTEM
# include <sys/stream.h>
# include <sys/ptem.h>
#endif

#include <stdio.h>
#include <assert.h>
#include <setjmp.h>
#include <grp.h>
#include <pwd.h>
#include <getopt.h>
#include <signal.h>

/* Get mbstate_t, mbrtowc(), mbsinit(), wcwidth().  */
#if HAVE_WCHAR_H
# include <wchar.h>
#endif

/* Get iswprint().  */
#if HAVE_WCTYPE_H
# include <wctype.h>
#endif
#if !defined iswprint && !HAVE_ISWPRINT
# define iswprint(wc) 1
#endif

#ifndef HAVE_DECL_WCWIDTH
"this configure-time declaration test was not run"
#endif
#if !HAVE_DECL_WCWIDTH
int wcwidth ();
#endif

/* If wcwidth() doesn't exist, assume all printable characters have
   width 1.  */
#ifndef wcwidth
# if !HAVE_WCWIDTH
#  define wcwidth(wc) ((wc) == 0 ? 0 : iswprint (wc) ? 1 : -1)
# endif
#endif

#include "system.h"
#include <fnmatch.h>

#include "acl.h"
#include "argmatch.h"
#include "dev-ino.h"
#include "dirname.h"
#include "dirfd.h"
#include "error.h"
#include "full-write.h"
#include "hard-locale.h"
#include "hash.h"
#include "human.h"
#include "filemode.h"
#include "inttostr.h"
#include "ls.h"
#include "mbswidth.h"
#include "obstack.h"
#include "path-concat.h"
#include "quote.h"
#include "quotearg.h"
#include "same.h"
#include "strftime.h"
#include "strverscmp.h"
#include "xstrtol.h"
#include "xreadlink.h"

#define PROGRAM_NAME (ls_mode == LS_LS ? "ls" \
                      : (ls_mode == LS_MULTI_COL \
                         ? "dir" : "vdir"))

#define AUTHORS "Richard Stallman", "David MacKenzie"

#define obstack_chunk_alloc malloc
#define obstack_chunk_free free

/* Return an int indicating the result of comparing two integers.
   Subtracting doesn't always work, due to overflow.  */
#define longdiff(a, b) ((a) < (b) ? -1 : (a) > (b))

/* Arrange to make lstat calls go through the wrapper function
   on systems with an lstat function that does not dereference symlinks
   that are specified with a trailing slash.  */
#if ! LSTAT_FOLLOWS_SLASHED_SYMLINK
int rpl_lstat (const char *, struct stat *);
# undef lstat
# define lstat(Name, Stat_buf) rpl_lstat(Name, Stat_buf)
#endif

#if HAVE_STRUCT_DIRENT_D_TYPE && defined DTTOIF
# define DT_INIT(Val) = Val
#else
# define DT_INIT(Val) /* empty */
#endif

#ifdef ST_MTIM_NSEC
# define TIMESPEC_NS(timespec) ((timespec).ST_MTIM_NSEC)
#else
# define TIMESPEC_NS(timespec) 0
#endif

#if ! HAVE_STRUCT_STAT_ST_AUTHOR
# define st_author st_uid
#endif

/* Cray/Unicos DMF: use the file's migrated, not real, status */
#if HAVE_ST_DM_MODE
# define ST_DM_MODE(Stat_buf) ((Stat_buf).st_dm_mode)
#else
# define ST_DM_MODE(Stat_buf) ((Stat_buf).st_mode)
#endif

enum filetype
  {
    unknown DT_INIT (DT_UNKNOWN),
    fifo DT_INIT (DT_FIFO),
    chardev DT_INIT (DT_CHR),
    directory DT_INIT (DT_DIR),
    blockdev DT_INIT (DT_BLK),
    normal DT_INIT (DT_REG),
    symbolic_link DT_INIT (DT_LNK),
    sock DT_INIT (DT_SOCK),
    arg_directory DT_INIT (2 * (DT_UNKNOWN | DT_FIFO | DT_CHR | DT_DIR | DT_BLK
                                | DT_REG | DT_LNK | DT_SOCK))
  };

struct fileinfo
  {
    /* The file name. */
    char *name;

    struct stat stat;

    /* For symbolic link, name of the file linked to, otherwise zero. */
    char *linkname;

    /* For symbolic link and long listing, st_mode of file linked to, otherwise
       zero. */
    mode_t linkmode;

    /* For symbolic link and color printing, 1 if linked-to file
       exists, otherwise 0.  */
    int linkok;

    enum filetype filetype;

#if HAVE_ACL
    /* For long listings, true if the file has an access control list.  */
    bool have_acl;
#endif
  };

#if HAVE_ACL
# define FILE_HAS_ACL(F) ((F)->have_acl)
#else
# define FILE_HAS_ACL(F) 0
#endif

#define LEN_STR_PAIR(s) sizeof (s) - 1, s

/* Null is a valid character in a color indicator (think about Epson
   printers, for example) so we have to use a length/buffer string
   type.  */

struct bin_str
  {
    size_t len;                 /* Number of bytes */
    const char *string;         /* Pointer to the same */
  };

#ifndef STDC_HEADERS
time_t time ();
#endif

char *getgroup ();
char *getuser ();

static size_t quote_name (FILE *out, const char *name,
                          struct quoting_options const *options,
                          size_t *width);
static char *make_link_path (const char *path, const char *linkname);
static int decode_switches (int argc, char **argv);
static int file_interesting (const struct dirent *next);
static uintmax_t gobble_file (const char *name, enum filetype type,
                              int explicit_arg, const char *dirname);
static void print_color_indicator (const char *name, mode_t mode, int linkok);
static void put_indicator (const struct bin_str *ind);
static int put_indicator_direct (const struct bin_str *ind);
static void add_ignore_pattern (const char *pattern);
static void attach (char *dest, const char *dirname, const char *name);
static void clear_files (void);
static void extract_dirs_from_files (const char *dirname,
                                     int ignore_dot_and_dot_dot);
static void get_link_name (const char *filename, struct fileinfo *f);
static void indent (size_t from, size_t to);
static size_t calculate_columns (bool by_columns);
static void print_current_files (void);
static void print_dir (const char *name, const char *realname);
static void print_file_name_and_frills (const struct fileinfo *f);
static void print_horizontal (void);
static int format_user_width (uid_t u);
static int format_group_width (gid_t g);
static void print_long_format (const struct fileinfo *f);
static void print_many_per_line (void);
static void print_name_with_quoting (const char *p, mode_t mode,
                                     int linkok,
                                     struct obstack *stack);
static void prep_non_filename_text (void);
static void print_type_indicator (mode_t mode);
static void print_with_commas (void);
static void queue_directory (const char *name, const char *realname);
static void sort_files (void);
static void parse_ls_color (void);
void usage (int status);

/* The name the program was run with, stripped of any leading path. */
char *program_name;

/* Initial size of hash table.
   Most hierarchies are likely to be shallower than this.  */
#define INITIAL_TABLE_SIZE 30

/* The set of `active' directories, from the current command-line argument
   to the level in the hierarchy at which files are being listed.
   A directory is represented by its device and inode numbers (struct dev_ino).
   A directory is added to this set when ls begins listing it or its
   entries, and it is removed from the set just after ls has finished
   processing it.  This set is used solely to detect loops, e.g., with
   mkdir loop; cd loop; ln -s ../loop sub; ls -RL  */
static Hash_table *active_dir_set;

#define LOOP_DETECT (!!active_dir_set)

/* The table of files in the current directory:

   `files' points to a vector of `struct fileinfo', one per file.
   `nfiles' is the number of elements space has been allocated for.
   `files_index' is the number actually in use.  */

/* Address of block containing the files that are described.  */
static struct fileinfo *files;  /* FIXME: rename this to e.g. cwd_file */

/* Length of block that `files' points to, measured in files.  */
static size_t nfiles;  /* FIXME: rename this to e.g. cwd_n_alloc */

/* Index of first unused in `files'.  */
static size_t files_index;  /* FIXME: rename this to e.g. cwd_n_used */

/* When nonzero, in a color listing, color each symlink name according to the
   type of file it points to.  Otherwise, color them according to the `ln'
   directive in LS_COLORS.  Dangling (orphan) symlinks are treated specially,
   regardless.  This is set when `ln=target' appears in LS_COLORS.  */

static int color_symlink_as_referent;

/* mode of appropriate file for colorization */
#define FILE_OR_LINK_MODE(File) \
    ((color_symlink_as_referent && (File)->linkok) \
     ? (File)->linkmode : (File)->stat.st_mode)


/* Record of one pending directory waiting to be listed.  */

struct pending
  {
    char *name;
    /* If the directory is actually the file pointed to by a symbolic link we
       were told to list, `realname' will contain the name of the symbolic
       link, otherwise zero. */
    char *realname;
    struct pending *next;
  };

static struct pending *pending_dirs;

/* Current time in seconds and nanoseconds since 1970, updated as
   needed when deciding whether a file is recent.  */

static time_t current_time = TYPE_MINIMUM (time_t);
static int current_time_ns = -1;

/* The number of bytes to use for columns containing inode numbers,
   block sizes, link counts, owners, groups, authors, major device
   numbers, minor device numbers, and file sizes, respectively.  */

static int inode_number_width;
static int block_size_width;
static int nlink_width;
static int owner_width;
static int group_width;
static int author_width;
static int major_device_number_width;
static int minor_device_number_width;
static int file_size_width;

/* Option flags */

/* long_format for lots of info, one per line.
   one_per_line for just names, one per line.
   many_per_line for just names, many per line, sorted vertically.
   horizontal for just names, many per line, sorted horizontally.
   with_commas for just names, many per line, separated by commas.

   -l (and other options that imply -l), -1, -C, -x and -m control
   this parameter.  */

enum format
  {
    long_format,                /* -l and other options that imply -l */
    one_per_line,               /* -1 */
    many_per_line,              /* -C */
    horizontal,                 /* -x */
    with_commas                 /* -m */
  };

static enum format format;

/* `full-iso' uses full ISO-style dates and times.  `long-iso' uses longer
   ISO-style time stamps, though shorter than `full-iso'.  `iso' uses shorter
   ISO-style time stamps.  `locale' uses locale-dependent time stamps.  */
enum time_style
  {
    full_iso_time_style,        /* --time-style=full-iso */
    long_iso_time_style,        /* --time-style=long-iso */
    iso_time_style,             /* --time-style=iso */
    locale_time_style           /* --time-style=locale */
  };

static char const *const time_style_args[] =
{
  "full-iso", "long-iso", "iso", "locale", 0
};

static enum time_style const time_style_types[] =
{
  full_iso_time_style, long_iso_time_style, iso_time_style,
  locale_time_style, 0
};

/* Type of time to print or sort by.  Controlled by -c and -u.  */

enum time_type
  {
    time_mtime,                 /* default */
    time_ctime,                 /* -c */
    time_atime                  /* -u */
  };

static enum time_type time_type;

/* The file characteristic to sort by.  Controlled by -t, -S, -U, -X, -v. */

enum sort_type
  {
    sort_none,                  /* -U */
    sort_name,                  /* default */
    sort_extension,             /* -X */
    sort_time,                  /* -t */
    sort_size,                  /* -S */
    sort_version                /* -v */
  };

static enum sort_type sort_type;

/* Direction of sort.
   0 means highest first if numeric,
   lowest first if alphabetic;
   these are the defaults.
   1 means the opposite order in each case.  -r  */

static int sort_reverse;

/* Nonzero means to display owner information.  -g turns this off.  */

static int print_owner = 1;

/* Nonzero means to display author information.  */

static bool print_author;

/* Nonzero means to display group information.  -G and -o turn this off.  */

static int print_group = 1;

/* Nonzero means print the user and group id's as numbers rather
   than as names.  -n  */

static int numeric_ids;

/* Nonzero means mention the size in blocks of each file.  -s  */

static int print_block_size;

/* Human-readable options for output.  */
static int human_output_opts;

/* The units to use when printing sizes other than file sizes.  */
static uintmax_t output_block_size;

/* Likewise, but for file sizes.  */
static uintmax_t file_output_block_size = 1;

/* Precede each line of long output (per file) with a string like `m,n:'
   where M is the number of characters after the `:' and before the
   filename and N is the length of the filename.  Using this format,
   Emacs' dired mode starts up twice as fast, and can handle all
   strange characters in file names.  */
static int dired;

/* `none' means don't mention the type of files.
   `classify' means mention file types and mark executables.
   `file_type' means mention only file types.

   Controlled by -F, -p, and --indicator-style.  */

enum indicator_style
  {
    none,       /*     --indicator-style=none */
    classify,   /* -F, --indicator-style=classify */
    file_type   /* -p, --indicator-style=file-type */
  };

static enum indicator_style indicator_style;

/* Names of indicator styles.  */
static char const *const indicator_style_args[] =
{
  "none", "classify", "file-type", 0
};

static enum indicator_style const indicator_style_types[]=
{
  none, classify, file_type
};

/* Nonzero means use colors to mark types.  Also define the different
   colors as well as the stuff for the LS_COLORS environment variable.
   The LS_COLORS variable is now in a termcap-like format.  */

static int print_with_color;

enum color_type
  {
    color_never,                /* 0: default or --color=never */
    color_always,               /* 1: --color=always */
    color_if_tty                /* 2: --color=tty */
  };

enum Dereference_symlink
  {
    DEREF_UNDEFINED = 1,
    DEREF_NEVER,
    DEREF_COMMAND_LINE_ARGUMENTS,       /* -H */
    DEREF_COMMAND_LINE_SYMLINK_TO_DIR,  /* the default, in certain cases */
    DEREF_ALWAYS                        /* -L */
  };

enum indicator_no
  {
    C_LEFT, C_RIGHT, C_END, C_NORM, C_FILE, C_DIR, C_LINK, C_FIFO, C_SOCK,
    C_BLK, C_CHR, C_MISSING, C_ORPHAN, C_EXEC, C_DOOR
  };

static const char *const indicator_name[]=
  {
    "lc", "rc", "ec", "no", "fi", "di", "ln", "pi", "so",
    "bd", "cd", "mi", "or", "ex", "do", NULL
  };

struct color_ext_type
  {
    struct bin_str ext;         /* The extension we're looking for */
    struct bin_str seq;         /* The sequence to output when we do */
    struct color_ext_type *next;        /* Next in list */
  };

static struct bin_str color_indicator[] =
  {
    { LEN_STR_PAIR ("\033[") },         /* lc: Left of color sequence */
    { LEN_STR_PAIR ("m") },             /* rc: Right of color sequence */
    { 0, NULL },                        /* ec: End color (replaces lc+no+rc) */
    { LEN_STR_PAIR ("0") },             /* no: Normal */
    { LEN_STR_PAIR ("0") },             /* fi: File: default */
    { LEN_STR_PAIR ("01;34") },         /* di: Directory: bright blue */
    { LEN_STR_PAIR ("01;36") },         /* ln: Symlink: bright cyan */
    { LEN_STR_PAIR ("33") },            /* pi: Pipe: yellow/brown */
    { LEN_STR_PAIR ("01;35") },         /* so: Socket: bright magenta */
    { LEN_STR_PAIR ("01;33") },         /* bd: Block device: bright yellow */
    { LEN_STR_PAIR ("01;33") },         /* cd: Char device: bright yellow */
    { 0, NULL },                        /* mi: Missing file: undefined */
    { 0, NULL },                        /* or: Orphanned symlink: undefined */
    { LEN_STR_PAIR ("01;32") },         /* ex: Executable: bright green */
    { LEN_STR_PAIR ("01;35") }          /* do: Door: bright magenta */
  };

/* FIXME: comment  */
static struct color_ext_type *color_ext_list = NULL;

/* Buffer for color sequences */
static char *color_buf;

/* Nonzero means to check for orphaned symbolic link, for displaying
   colors.  */

static int check_symlink_color;

/* Nonzero means mention the inode number of each file.  -i  */

static int print_inode;

/* What to do with symbolic links.  Affected by -d, -F, -H, -l (and
   other options that imply -l), and -L.  */

static enum Dereference_symlink dereference;

/* Nonzero means when a directory is found, display info on its
   contents.  -R  */

static int recursive;

/* Nonzero means when an argument is a directory name, display info
   on it itself.  -d  */

static int immediate_dirs;

/* Nonzero means don't omit files whose names start with `.'.  -A */

static int all_files;

/* Nonzero means don't omit files `.' and `..'
   This flag implies `all_files'.  -a  */

static int really_all_files;

/* A linked list of shell-style globbing patterns.  If a non-argument
   file name matches any of these patterns, it is omitted.
   Controlled by -I.  Multiple -I options accumulate.
   The -B option adds `*~' and `.*~' to this list.  */

struct ignore_pattern
  {
    const char *pattern;
    struct ignore_pattern *next;
  };

static struct ignore_pattern *ignore_patterns;

/* Nonzero means output nongraphic chars in file names as `?'.
   (-q, --hide-control-chars)
   qmark_funny_chars and the quoting style (-Q, --quoting-style=WORD) are
   independent.  The algorithm is: first, obey the quoting style to get a
   string representing the file name;  then, if qmark_funny_chars is set,
   replace all nonprintable chars in that string with `?'.  It's necessary
   to replace nonprintable chars even in quoted strings, because we don't
   want to mess up the terminal if control chars get sent to it, and some
   quoting methods pass through control chars as-is.  */
static int qmark_funny_chars;

/* Quoting options for file and dir name output.  */

static struct quoting_options *filename_quoting_options;
static struct quoting_options *dirname_quoting_options;

/* The number of chars per hardware tab stop.  Setting this to zero
   inhibits the use of TAB characters for separating columns.  -T */
static size_t tabsize;

/* Nonzero means we are listing the working directory because no
   non-option arguments were given. */

static int dir_defaulted;

/* Nonzero means print each directory name before listing it. */

static int print_dir_name;

/* The line length to use for breaking lines in many-per-line format.
   Can be set with -w.  */

static size_t line_length;

/* If nonzero, the file listing format requires that stat be called on
   each file. */

static int format_needs_stat;

/* Similar to `format_needs_stat', but set if only the file type is
   needed.  */

static int format_needs_type;

/* strftime formats for non-recent and recent files, respectively, in
   -l output.  */

static char const *long_time_format[2] =
  {
    /* strftime format for non-recent files (older than 6 months), in
       -l output when --time-style=locale is specified.  This should
       contain the year, month and day (at least), in an order that is
       understood by people in your locale's territory.
       Please try to keep the number of used screen columns small,
       because many people work in windows with only 80 columns.  But
       make this as wide as the other string below, for recent files.  */
    N_("%b %e  %Y"),
    /* strftime format for recent files (younger than 6 months), in
       -l output when --time-style=locale is specified.  This should
       contain the month, day and time (at least), in an order that is
       understood by people in your locale's territory.
       Please try to keep the number of used screen columns small,
       because many people work in windows with only 80 columns.  But
       make this as wide as the other string above, for non-recent files.  */
    N_("%b %e %H:%M")
  };

/* The exit status to use if we don't get any fatal errors. */

static int exit_status;

/* For long options that have no equivalent short option, use a
   non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
enum
{
  AUTHOR_OPTION = CHAR_MAX + 1,
  BLOCK_SIZE_OPTION,
  COLOR_OPTION,
  DEREFERENCE_COMMAND_LINE_SYMLINK_TO_DIR_OPTION,
  FORMAT_OPTION,
  FULL_TIME_OPTION,
  INDICATOR_STYLE_OPTION,
  QUOTING_STYLE_OPTION,
  SHOW_CONTROL_CHARS_OPTION,
  SI_OPTION,
  SORT_OPTION,
  TIME_OPTION,
  TIME_STYLE_OPTION
};

static struct option const long_options[] =
{
  {"all", no_argument, 0, 'a'},
  {"escape", no_argument, 0, 'b'},
  {"directory", no_argument, 0, 'd'},
  {"dired", no_argument, 0, 'D'},
  {"full-time", no_argument, 0, FULL_TIME_OPTION},
  {"human-readable", no_argument, 0, 'h'},
  {"inode", no_argument, 0, 'i'},
  {"kilobytes", no_argument, 0, 'k'}, /* long form is obsolescent */
  {"numeric-uid-gid", no_argument, 0, 'n'},
  {"no-group", no_argument, 0, 'G'},
  {"hide-control-chars", no_argument, 0, 'q'},
  {"reverse", no_argument, 0, 'r'},
  {"size", no_argument, 0, 's'},
  {"width", required_argument, 0, 'w'},
  {"almost-all", no_argument, 0, 'A'},
  {"ignore-backups", no_argument, 0, 'B'},
  {"classify", no_argument, 0, 'F'},
  {"file-type", no_argument, 0, 'p'},
  {"si", no_argument, 0, SI_OPTION},
  {"dereference-command-line", no_argument, 0, 'H'},
  {"dereference-command-line-symlink-to-dir", no_argument, 0,
   DEREFERENCE_COMMAND_LINE_SYMLINK_TO_DIR_OPTION},
  {"ignore", required_argument, 0, 'I'},
  {"indicator-style", required_argument, 0, INDICATOR_STYLE_OPTION},
  {"dereference", no_argument, 0, 'L'},
  {"literal", no_argument, 0, 'N'},
  {"quote-name", no_argument, 0, 'Q'},
  {"quoting-style", required_argument, 0, QUOTING_STYLE_OPTION},
  {"recursive", no_argument, 0, 'R'},
  {"format", required_argument, 0, FORMAT_OPTION},
  {"show-control-chars", no_argument, 0, SHOW_CONTROL_CHARS_OPTION},
  {"sort", required_argument, 0, SORT_OPTION},
  {"tabsize", required_argument, 0, 'T'},
  {"time", required_argument, 0, TIME_OPTION},
  {"time-style", required_argument, 0, TIME_STYLE_OPTION},
  {"color", optional_argument, 0, COLOR_OPTION},
  {"block-size", required_argument, 0, BLOCK_SIZE_OPTION},
  {"author", no_argument, 0, AUTHOR_OPTION},
  {GETOPT_HELP_OPTION_DECL},
  {GETOPT_VERSION_OPTION_DECL},
  {NULL, 0, NULL, 0}
};

static char const *const format_args[] =
{
  "verbose", "long", "commas", "horizontal", "across",
  "vertical", "single-column", 0
};

static enum format const format_types[] =
{
  long_format, long_format, with_commas, horizontal, horizontal,
  many_per_line, one_per_line
};

static char const *const sort_args[] =
{
  "none", "time", "size", "extension", "version", 0
};

static enum sort_type const sort_types[] =
{
  sort_none, sort_time, sort_size, sort_extension, sort_version
};

static char const *const time_args[] =
{
  "atime", "access", "use", "ctime", "status", 0
};

static enum time_type const time_types[] =
{
  time_atime, time_atime, time_atime, time_ctime, time_ctime
};

static char const *const color_args[] =
{
  /* force and none are for compatibility with another color-ls version */
  "always", "yes", "force",
  "never", "no", "none",
  "auto", "tty", "if-tty", 0
};

static enum color_type const color_types[] =
{
  color_always, color_always, color_always,
  color_never, color_never, color_never,
  color_if_tty, color_if_tty, color_if_tty
};

/* Information about filling a column.  */
struct column_info
{
  bool valid_len;
  size_t line_len;
  size_t *col_arr;
};

/* Array with information about column filledness.  */
static struct column_info *column_info;

/* Maximum number of columns ever possible for this display.  */
static size_t max_idx;

/* The minimum width of a colum is 3: 1 character for the name and 2
   for the separating white space.  */
#define MIN_COLUMN_WIDTH        3


/* This zero-based index is used solely with the --dired option.
   When that option is in effect, this counter is incremented for each
   character of output generated by this program so that the beginning
   and ending indices (in that output) of every file name can be recorded
   and later output themselves.  */
static size_t dired_pos;

#define DIRED_PUTCHAR(c) do {putchar ((c)); ++dired_pos;} while (0)

/* Write S to STREAM and increment DIRED_POS by S_LEN.  */
#define DIRED_FPUTS(s, stream, s_len) \
    do {fputs ((s), (stream)); dired_pos += s_len;} while (0)

/* Like DIRED_FPUTS, but for use when S is a literal string.  */
#define DIRED_FPUTS_LITERAL(s, stream) \
    do {fputs ((s), (stream)); dired_pos += sizeof((s)) - 1;} while (0)

#define DIRED_INDENT()                                                  \
    do                                                                  \
      {                                                                 \
        if (dired)                                                      \
          DIRED_FPUTS_LITERAL ("  ", stdout);                           \
      }                                                                 \
    while (0)

/* With --dired, store pairs of beginning and ending indices of filenames.  */
static struct obstack dired_obstack;

/* With --dired, store pairs of beginning and ending indices of any
   directory names that appear as headers (just before `total' line)
   for lists of directory entries.  Such directory names are seen when
   listing hierarchies using -R and when a directory is listed with at
   least one other command line argument.  */
static struct obstack subdired_obstack;

/* Save the current index on the specified obstack, OBS.  */
#define PUSH_CURRENT_DIRED_POS(obs)                                     \
  do                                                                    \
    {                                                                   \
      if (dired)                                                        \
        obstack_grow ((obs), &dired_pos, sizeof (dired_pos));           \
    }                                                                   \
  while (0)

/* With -R, this stack is used to help detect directory cycles.
   The device/inode pairs on this stack mirror the pairs in the
   active_dir_set hash table.  */
static struct obstack dev_ino_obstack;

/* Push a pair onto the device/inode stack.  */
#define DEV_INO_PUSH(Dev, Ino)                                          \
  do                                                                    \
    {                                                                   \
      struct dev_ino *di;                                               \
      obstack_blank (&dev_ino_obstack, sizeof (struct dev_ino));        \
      di = -1 + (struct dev_ino *) obstack_next_free (&dev_ino_obstack); \
      di->st_dev = (Dev);                                               \
      di->st_ino = (Ino);                                               \
    }                                                                   \
  while (0)

/* Pop a dev/ino struct off the global dev_ino_obstack
   and return that struct.  */
static struct dev_ino
dev_ino_pop (void)
{
  assert (sizeof (struct dev_ino) <= obstack_object_size (&dev_ino_obstack));
  obstack_blank (&dev_ino_obstack, -(int) (sizeof (struct dev_ino)));
  return *(struct dev_ino*) obstack_next_free (&dev_ino_obstack);
}

#define ASSERT_MATCHING_DEV_INO(Name, Di)       \
  do                                            \
    {                                           \
      struct stat sb;                           \
      assert (Name);                            \
      assert (0 <= stat (Name, &sb));           \
      assert (sb.st_dev == Di.st_dev);          \
      assert (sb.st_ino == Di.st_ino);          \
    }                                           \
  while (0)


/* Write to standard output PREFIX, followed by the quoting style and
   a space-separated list of the integers stored in OS all on one line.  */

static void
dired_dump_obstack (const char *prefix, struct obstack *os)
{
  size_t n_pos;

  n_pos = obstack_object_size (os) / sizeof (dired_pos);
  if (n_pos > 0)
    {
      size_t i;
      size_t *pos;

      pos = (size_t *) obstack_finish (os);
      fputs (prefix, stdout);
      for (i = 0; i < n_pos; i++)
        printf (" %lu", (unsigned long int) pos[i]);
      putchar ('\n');
    }
}

static size_t
dev_ino_hash (void const *x, size_t table_size)
{
  struct dev_ino const *p = x;
  return (uintmax_t) p->st_ino % table_size;
}

static bool
dev_ino_compare (void const *x, void const *y)
{
  struct dev_ino const *a = x;
  struct dev_ino const *b = y;
  return SAME_INODE (*a, *b) ? true : false;
}

static void
dev_ino_free (void *x)
{
  free (x);
}

/* Add the device/inode pair (P->st_dev/P->st_ino) to the set of
   active directories.  Return nonzero if there is already a matching
   entry in the table.  Otherwise, return zero.  */

static int
visit_dir (dev_t dev, ino_t ino)
{
  struct dev_ino *ent;
  struct dev_ino *ent_from_table;
  int found_match;

  ent = xmalloc (sizeof *ent);
  ent->st_ino = ino;
  ent->st_dev = dev;

  /* Attempt to insert this entry into the table.  */
  ent_from_table = hash_insert (active_dir_set, ent);

  if (ent_from_table == NULL)
    {
      /* Insertion failed due to lack of memory.  */
      xalloc_die ();
    }

  found_match = (ent_from_table != ent);

  if (found_match)
    {
      /* ent was not inserted, so free it.  */
      free (ent);
    }

  return found_match;
}

static void
free_pending_ent (struct pending *p)
{
  if (p->name)
    free (p->name);
  if (p->realname)
    free (p->realname);
  free (p);
}

static void
restore_default_color (void)
{
  if (put_indicator_direct (&color_indicator[C_LEFT]) == 0)
    put_indicator_direct (&color_indicator[C_RIGHT]);
}

/* Upon interrupt, suspend, hangup, etc. ensure that the
   terminal text color is restored to the default.  */
static void
sighandler (int sig)
{
#ifndef SA_NOCLDSTOP
  signal (sig, SIG_IGN);
#endif

  restore_default_color ();

  /* SIGTSTP is special, since the application can receive that signal more
     than once.  In this case, don't set the signal handler to the default.
     Instead, just raise the uncatchable SIGSTOP.  */
  if (sig == SIGTSTP)
    {
      sig = SIGSTOP;
    }
  else
    {
#ifdef SA_NOCLDSTOP
      struct sigaction sigact;

      sigact.sa_handler = SIG_DFL;
      sigemptyset (&sigact.sa_mask);
      sigact.sa_flags = 0;
      sigaction (sig, &sigact, NULL);
#else
      signal (sig, SIG_DFL);
#endif
    }

  raise (sig);
}

int
main (int argc, char **argv)
{
  register int i;
  register struct pending *thispend;
  unsigned int n_files;

  initialize_main (&argc, &argv);
  program_name = argv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

#define N_ENTRIES(Array) (sizeof Array / sizeof *(Array))
  assert (N_ENTRIES (color_indicator) + 1 == N_ENTRIES (indicator_name));

  exit_status = 0;
  dir_defaulted = 1;
  print_dir_name = 1;
  pending_dirs = 0;

  i = decode_switches (argc, argv);

  if (print_with_color)
    parse_ls_color ();

  /* Test print_with_color again, because the call to parse_ls_color
     may have just reset it -- e.g., if LS_COLORS is invalid.  */
  if (print_with_color)
    {
      prep_non_filename_text ();
      /* Avoid following symbolic links when possible.  */
      if (color_indicator[C_ORPHAN].string != NULL
          || (color_indicator[C_MISSING].string != NULL
              && format == long_format))
        check_symlink_color = 1;

      {
        unsigned int j;
        static int const sigs[] = { SIGHUP, SIGINT, SIGPIPE,
                                    SIGQUIT, SIGTERM, SIGTSTP };
        unsigned int nsigs = sizeof sigs / sizeof *sigs;
#ifdef SA_NOCLDSTOP
        struct sigaction oldact, newact;
        sigset_t caught_signals;

        sigemptyset (&caught_signals);
        for (j = 0; j < nsigs; j++)
          sigaddset (&caught_signals, sigs[j]);
        newact.sa_handler = sighandler;
        newact.sa_mask = caught_signals;
        newact.sa_flags = 0;
#endif

        for (j = 0; j < nsigs; j++)
          {
            int sig = sigs[j];
#ifdef SA_NOCLDSTOP
            sigaction (sig, NULL, &oldact);
            if (oldact.sa_handler != SIG_IGN)
              sigaction (sig, &newact, NULL);
#else
            if (signal (sig, SIG_IGN) != SIG_IGN)
              signal (sig, sighandler);
#endif
          }
      }
    }

  if (dereference == DEREF_UNDEFINED)
    dereference = ((immediate_dirs
                    || indicator_style == classify
                    || format == long_format)
                   ? DEREF_NEVER
                   : DEREF_COMMAND_LINE_SYMLINK_TO_DIR);

  /* When using -R, initialize a data structure we'll use to
     detect any directory cycles.  */
  if (recursive)
    {
      active_dir_set = hash_initialize (INITIAL_TABLE_SIZE, NULL,
                                        dev_ino_hash,
                                        dev_ino_compare,
                                        dev_ino_free);
      if (active_dir_set == NULL)
        xalloc_die ();

      obstack_init (&dev_ino_obstack);
    }

  format_needs_stat = sort_type == sort_time || sort_type == sort_size
    || format == long_format
    || dereference == DEREF_ALWAYS
    || print_block_size || print_inode;
  format_needs_type = (format_needs_stat == 0
                       && (recursive || print_with_color
                           || indicator_style != none));

  if (dired)
    {
      obstack_init (&dired_obstack);
      obstack_init (&subdired_obstack);
    }

  nfiles = 100;
  files = xnmalloc (nfiles, sizeof *files);
  files_index = 0;

  clear_files ();

  n_files = argc - i;
  if (0 < n_files)
    dir_defaulted = 0;

  for (; i < argc; i++)
    {
      gobble_file (argv[i], unknown, 1, "");
    }

  if (dir_defaulted)
    {
      if (immediate_dirs)
        gobble_file (".", directory, 1, "");
      else
        queue_directory (".", 0);
    }

  if (files_index)
    {
      sort_files ();
      if (!immediate_dirs)
        extract_dirs_from_files ("", 0);
      /* `files_index' might be zero now.  */
    }

  /* In the following if/else blocks, it is sufficient to test `pending_dirs'
     (and not pending_dirs->name) because there may be no markers in the queue
     at this point.  A marker may be enqueued when extract_dirs_from_files is
     called with a non-empty string or via print_dir.  */
  if (files_index)
    {
      print_current_files ();
      if (pending_dirs)
        DIRED_PUTCHAR ('\n');
    }
  else if (n_files <= 1 && pending_dirs && pending_dirs->next == 0)
    print_dir_name = 0;

  while (pending_dirs)
    {
      thispend = pending_dirs;
      pending_dirs = pending_dirs->next;

      if (LOOP_DETECT)
        {
          if (thispend->name == NULL)
            {
              /* thispend->name == NULL means this is a marker entry
                 indicating we've finished processing the directory.
                 Use its dev/ino numbers to remove the corresponding
                 entry from the active_dir_set hash table.  */
              struct dev_ino di = dev_ino_pop ();
              struct dev_ino *found = hash_delete (active_dir_set, &di);
              /* ASSERT_MATCHING_DEV_INO (thispend->realname, di); */
              assert (found);
              dev_ino_free (found);
              free_pending_ent (thispend);
              continue;
            }
        }

      print_dir (thispend->name, thispend->realname);

      free_pending_ent (thispend);
      print_dir_name = 1;
    }

  if (dired)
    {
      /* No need to free these since we're about to exit.  */
      dired_dump_obstack ("//DIRED//", &dired_obstack);
      dired_dump_obstack ("//SUBDIRED//", &subdired_obstack);
      printf ("//DIRED-OPTIONS// --quoting-style=%s\n",
              quoting_style_args[get_quoting_style (filename_quoting_options)]);
    }

  /* Restore default color before exiting */
  if (print_with_color)
    {
      put_indicator (&color_indicator[C_LEFT]);
      put_indicator (&color_indicator[C_RIGHT]);
    }

  if (LOOP_DETECT)
    {
      assert (hash_get_n_entries (active_dir_set) == 0);
      hash_free (active_dir_set);
    }

  exit (exit_status);
}

/* Set all the option flags according to the switches specified.
   Return the index of the first non-option argument.  */

static int
decode_switches (int argc, char **argv)
{
  int c;
  char *time_style_option = 0;

  /* Record whether there is an option specifying sort type.  */
  int sort_type_specified = 0;

  qmark_funny_chars = 0;

  /* initialize all switches to default settings */

  switch (ls_mode)
    {
    case LS_MULTI_COL:
      /* This is for the `dir' program.  */
      format = many_per_line;
      set_quoting_style (NULL, escape_quoting_style);
      break;

    case LS_LONG_FORMAT:
      /* This is for the `vdir' program.  */
      format = long_format;
      set_quoting_style (NULL, escape_quoting_style);
      break;

    case LS_LS:
      /* This is for the `ls' program.  */
      if (isatty (STDOUT_FILENO))
        {
          format = many_per_line;
          /* See description of qmark_funny_chars, above.  */
          qmark_funny_chars = 1;
        }
      else
        {
          format = one_per_line;
          qmark_funny_chars = 0;
        }
      break;

    default:
      abort ();
    }

  time_type = time_mtime;
  sort_type = sort_name;
  sort_reverse = 0;
  numeric_ids = 0;
  print_block_size = 0;
  indicator_style = none;
  print_inode = 0;
  dereference = DEREF_UNDEFINED;
  recursive = 0;
  immediate_dirs = 0;
  all_files = 0;
  really_all_files = 0;
  ignore_patterns = 0;

  /* FIXME: put this in a function.  */
  {
    char const *q_style = getenv ("QUOTING_STYLE");
    if (q_style)
      {
        int i = ARGMATCH (q_style, quoting_style_args, quoting_style_vals);
        if (0 <= i)
          set_quoting_style (NULL, quoting_style_vals[i]);
        else
          error (0, 0,
         _("ignoring invalid value of environment variable QUOTING_STYLE: %s"),
                 quotearg (q_style));
      }
  }

  {
    char const *ls_block_size = getenv ("LS_BLOCK_SIZE");
    human_output_opts = human_options (ls_block_size, false,
                                       &output_block_size);
    if (ls_block_size || getenv ("BLOCK_SIZE"))
      file_output_block_size = output_block_size;
  }

  line_length = 80;
  {
    char const *p = getenv ("COLUMNS");
    if (p && *p)
      {
        unsigned long int tmp_ulong;
        if (xstrtoul (p, NULL, 0, &tmp_ulong, NULL) == LONGINT_OK
            && 0 < tmp_ulong && tmp_ulong <= SIZE_MAX)
          {
            line_length = tmp_ulong;
          }
        else
          {
            error (0, 0,
               _("ignoring invalid width in environment variable COLUMNS: %s"),
                   quotearg (p));
          }
      }
  }

#ifdef TIOCGWINSZ
  {
    struct winsize ws;

    if (ioctl (STDOUT_FILENO, TIOCGWINSZ, &ws) != -1
        && 0 < ws.ws_col /* && ws.ws_col <= SIZE_MAX */ )
      line_length = ws.ws_col;
  }
#endif

  /* Using the TABSIZE environment variable is not POSIX-approved.
     Ignore it when POSIXLY_CORRECT is set.  */
  {
    char const *p;
    tabsize = 8;
    if (!getenv ("POSIXLY_CORRECT") && (p = getenv ("TABSIZE")))
      {
        unsigned long int tmp_ulong;
        if (xstrtoul (p, NULL, 0, &tmp_ulong, NULL) == LONGINT_OK
            && tmp_ulong <= SIZE_MAX)
          {
            tabsize = tmp_ulong;
          }
        else
          {
            error (0, 0,
             _("ignoring invalid tab size in environment variable TABSIZE: %s"),
                   quotearg (p));
          }
      }
  }

  while ((c = getopt_long (argc, argv,
                           "abcdfghiklmnopqrstuvw:xABCDFGHI:LNQRST:UX1",
                           long_options, NULL)) != -1)
    {
      switch (c)
        {
        case 0:
          break;

        case 'a':
          all_files = 1;
          really_all_files = 1;
          break;

        case 'b':
          set_quoting_style (NULL, escape_quoting_style);
          break;

        case 'c':
          time_type = time_ctime;
          break;

        case 'd':
          immediate_dirs = 1;
          break;

        case 'f':
          /* Same as enabling -a -U and disabling -l -s.  */
          all_files = 1;
          really_all_files = 1;
          sort_type = sort_none;
          sort_type_specified = 1;
          /* disable -l */
          if (format == long_format)
            format = (isatty (STDOUT_FILENO) ? many_per_line : one_per_line);
          print_block_size = 0; /* disable -s */
          print_with_color = 0; /* disable --color */
          break;

        case 'g':
          format = long_format;
          print_owner = 0;
          break;

        case 'h':
          human_output_opts = human_autoscale | human_SI | human_base_1024;
          file_output_block_size = output_block_size = 1;
          break;

        case 'i':
          print_inode = 1;
          break;

        case 'k':
          human_output_opts = 0;
          file_output_block_size = output_block_size = 1024;
          break;

        case 'l':
          format = long_format;
          break;

        case 'm':
          format = with_commas;
          break;

        case 'n':
          numeric_ids = 1;
          format = long_format;
          break;

        case 'o':  /* Just like -l, but don't display group info.  */
          format = long_format;
          print_group = 0;
          break;

        case 'p':
          indicator_style = file_type;
          break;

        case 'q':
          qmark_funny_chars = 1;
          break;

        case 'r':
          sort_reverse = 1;
          break;

        case 's':
          print_block_size = 1;
          break;

        case 't':
          sort_type = sort_time;
          sort_type_specified = 1;
          break;

        case 'u':
          time_type = time_atime;
          break;

        case 'v':
          sort_type = sort_version;
          sort_type_specified = 1;
          break;

        case 'w':
          {
            unsigned long int tmp_ulong;
            if (xstrtoul (optarg, NULL, 0, &tmp_ulong, NULL) != LONGINT_OK
                || ! (0 < tmp_ulong && tmp_ulong <= SIZE_MAX))
              error (EXIT_FAILURE, 0, _("invalid line width: %s"),
                     quotearg (optarg));
            line_length = tmp_ulong;
            break;
          }

        case 'x':
          format = horizontal;
          break;

        case 'A':
          really_all_files = 0;
          all_files = 1;
          break;

        case 'B':
          add_ignore_pattern ("*~");
          add_ignore_pattern (".*~");
          break;

        case 'C':
          format = many_per_line;
          break;

        case 'D':
          dired = 1;
          break;

        case 'F':
          indicator_style = classify;
          break;

        case 'G':               /* inhibit display of group info */
          print_group = 0;
          break;

        case 'H':
          dereference = DEREF_COMMAND_LINE_ARGUMENTS;
          break;

        case DEREFERENCE_COMMAND_LINE_SYMLINK_TO_DIR_OPTION:
          dereference = DEREF_COMMAND_LINE_SYMLINK_TO_DIR;
          break;

        case 'I':
          add_ignore_pattern (optarg);
          break;

        case 'L':
          dereference = DEREF_ALWAYS;
          break;

        case 'N':
          set_quoting_style (NULL, literal_quoting_style);
          break;

        case 'Q':
          set_quoting_style (NULL, c_quoting_style);
          break;

        case 'R':
          recursive = 1;
          break;

        case 'S':
          sort_type = sort_size;
          sort_type_specified = 1;
          break;

        case 'T':
          {
            unsigned long int tmp_ulong;
            if (xstrtoul (optarg, NULL, 0, &tmp_ulong, NULL) != LONGINT_OK
                || SIZE_MAX < tmp_ulong)
              error (EXIT_FAILURE, 0, _("invalid tab size: %s"),
                     quotearg (optarg));
            tabsize = tmp_ulong;
            break;
          }

        case 'U':
          sort_type = sort_none;
          sort_type_specified = 1;
          break;

        case 'X':
          sort_type = sort_extension;
          sort_type_specified = 1;
          break;

        case '1':
          /* -1 has no effect after -l.  */
          if (format != long_format)
            format = one_per_line;
          break;

        case AUTHOR_OPTION:
          print_author = true;
          break;

        case SORT_OPTION:
          sort_type = XARGMATCH ("--sort", optarg, sort_args, sort_types);
          sort_type_specified = 1;
          break;

        case TIME_OPTION:
          time_type = XARGMATCH ("--time", optarg, time_args, time_types);
          break;

        case FORMAT_OPTION:
          format = XARGMATCH ("--format", optarg, format_args, format_types);
          break;

        case FULL_TIME_OPTION:
          format = long_format;
          time_style_option = "full-iso";
          break;

        case COLOR_OPTION:
          {
            int i;
            if (optarg)
              i = XARGMATCH ("--color", optarg, color_args, color_types);
            else
              /* Using --color with no argument is equivalent to using
                 --color=always.  */
              i = color_always;

            print_with_color = (i == color_always
                                || (i == color_if_tty
                                    && isatty (STDOUT_FILENO)));

            if (print_with_color)
              {
                /* Don't use TAB characters in output.  Some terminal
                   emulators can't handle the combination of tabs and
                   color codes on the same line.  */
                tabsize = 0;
              }
            break;
          }

        case INDICATOR_STYLE_OPTION:
          indicator_style = XARGMATCH ("--indicator-style", optarg,
                                       indicator_style_args,
                                       indicator_style_types);
          break;

        case QUOTING_STYLE_OPTION:
          set_quoting_style (NULL,
                             XARGMATCH ("--quoting-style", optarg,
                                        quoting_style_args,
                                        quoting_style_vals));
          break;

        case TIME_STYLE_OPTION:
          time_style_option = optarg;
          break;

        case SHOW_CONTROL_CHARS_OPTION:
          qmark_funny_chars = 0;
          break;

        case BLOCK_SIZE_OPTION:
          human_output_opts = human_options (optarg, true, &output_block_size);
          file_output_block_size = output_block_size;
          break;

        case SI_OPTION:
          human_output_opts = human_autoscale | human_SI;
          file_output_block_size = output_block_size = 1;
          break;

        case_GETOPT_HELP_CHAR;

        case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);

        default:
          usage (EXIT_FAILURE);
        }
    }

  max_idx = MAX (1, line_length / MIN_COLUMN_WIDTH);

  filename_quoting_options = clone_quoting_options (NULL);
  if (get_quoting_style (filename_quoting_options) == escape_quoting_style)
    set_char_quoting (filename_quoting_options, ' ', 1);
  if (indicator_style != none)
    {
      char const *p;
      for (p = "*=@|" + (int) indicator_style - 1;  *p;  p++)
        set_char_quoting (filename_quoting_options, *p, 1);
    }

  dirname_quoting_options = clone_quoting_options (NULL);
  set_char_quoting (dirname_quoting_options, ':', 1);

  /* --dired is meaningful only with --format=long (-l).
     Otherwise, ignore it.  FIXME: warn about this?
     Alternatively, make --dired imply --format=long?  */
  if (dired && format != long_format)
    dired = 0;

  /* If -c or -u is specified and not -l (or any other option that implies -l),
     and no sort-type was specified, then sort by the ctime (-c) or atime (-u).
     The behavior of ls when using either -c or -u but with neither -l nor -t
     appears to be unspecified by POSIX.  So, with GNU ls, `-u' alone means
     sort by atime (this is the one that's not specified by the POSIX spec),
     -lu means show atime and sort by name, -lut means show atime and sort
     by atime.  */

  if ((time_type == time_ctime || time_type == time_atime)
      && !sort_type_specified && format != long_format)
    {
      sort_type = sort_time;
    }

  if (format == long_format)
    {
      char *style = time_style_option;
      static char const posix_prefix[] = "posix-";

      if (! style)
        if (! (style = getenv ("TIME_STYLE")))
          style = "posix-long-iso";

      while (strncmp (style, posix_prefix, sizeof posix_prefix - 1) == 0)
        {
          if (! hard_locale (LC_TIME))
            return optind;
          style += sizeof posix_prefix - 1;
        }

      if (*style == '+')
        {
          char *p0 = style + 1;
          char *p1 = strchr (p0, '\n');
          if (! p1)
            p1 = p0;
          else
            {
              if (strchr (p1 + 1, '\n'))
                error (EXIT_FAILURE, 0, _("invalid time style format %s"),
                       quote (p0));
              *p1++ = '\0';
            }
          long_time_format[0] = p0;
          long_time_format[1] = p1;
        }
      else
        switch (XARGMATCH ("time style", style,
                           time_style_args,
                           time_style_types))
          {
          case full_iso_time_style:
            long_time_format[0] = long_time_format[1] =
              "%Y-%m-%d %H:%M:%S.%N %z";
            break;

          case long_iso_time_style:
            long_time_format[0] = long_time_format[1] = "%Y-%m-%d %H:%M";
            break;

          case iso_time_style:
            long_time_format[0] = "%Y-%m-%d ";
            long_time_format[1] = "%m-%d %H:%M";
            break;

          case locale_time_style:
            if (hard_locale (LC_TIME))
              {
                unsigned int i;
                for (i = 0; i < 2; i++)
                  long_time_format[i] =
                    dcgettext (NULL, long_time_format[i], LC_TIME);
              }
          }
    }

  return optind;
}

/* Parse a string as part of the LS_COLORS variable; this may involve
   decoding all kinds of escape characters.  If equals_end is set an
   unescaped equal sign ends the string, otherwise only a : or \0
   does.  Set *OUTPUT_COUNT to the number of bytes output.  Return
   true if successful.

   The resulting string is *not* null-terminated, but may contain
   embedded nulls.

   Note that both dest and src are char **; on return they point to
   the first free byte after the array and the character that ended
   the input string, respectively.  */

static bool
get_funky_string (char **dest, const char **src, bool equals_end,
                  size_t *output_count)
{
  int num;                      /* For numerical codes */
  size_t count;                 /* Something to count with */
  enum {
    ST_GND, ST_BACKSLASH, ST_OCTAL, ST_HEX, ST_CARET, ST_END, ST_ERROR
  } state;
  const char *p;
  char *q;

  p = *src;                     /* We don't want to double-indirect */
  q = *dest;                    /* the whole darn time.  */

  count = 0;                    /* No characters counted in yet.  */
  num = 0;

  state = ST_GND;               /* Start in ground state.  */
  while (state < ST_END)
    {
      switch (state)
        {
        case ST_GND:            /* Ground state (no escapes) */
          switch (*p)
            {
            case ':':
            case '\0':
              state = ST_END;   /* End of string */
              break;
            case '\\':
              state = ST_BACKSLASH; /* Backslash scape sequence */
              ++p;
              break;
            case '^':
              state = ST_CARET; /* Caret escape */
              ++p;
              break;
            case '=':
              if (equals_end)
                {
                  state = ST_END; /* End */
                  break;
                }
              /* else fall through */
            default:
              *(q++) = *(p++);
              ++count;
              break;
            }
          break;

        case ST_BACKSLASH:      /* Backslash escaped character */
          switch (*p)
            {
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
              state = ST_OCTAL; /* Octal sequence */
              num = *p - '0';
              break;
            case 'x':
            case 'X':
              state = ST_HEX;   /* Hex sequence */
              num = 0;
              break;
            case 'a':           /* Bell */
              num = 7;          /* Not all C compilers know what \a means */
              break;
            case 'b':           /* Backspace */
              num = '\b';
              break;
            case 'e':           /* Escape */
              num = 27;
              break;
            case 'f':           /* Form feed */
              num = '\f';
              break;
            case 'n':           /* Newline */
              num = '\n';
              break;
            case 'r':           /* Carriage return */
              num = '\r';
              break;
            case 't':           /* Tab */
              num = '\t';
              break;
            case 'v':           /* Vtab */
              num = '\v';
              break;
            case '?':           /* Delete */
              num = 127;
              break;
            case '_':           /* Space */
              num = ' ';
              break;
            case '\0':          /* End of string */
              state = ST_ERROR; /* Error! */
              break;
            default:            /* Escaped character like \ ^ : = */
              num = *p;
              break;
            }
          if (state == ST_BACKSLASH)
            {
              *(q++) = num;
              ++count;
              state = ST_GND;
            }
          ++p;
          break;

        case ST_OCTAL:          /* Octal sequence */
          if (*p < '0' || *p > '7')
            {
              *(q++) = num;
              ++count;
              state = ST_GND;
            }
          else
            num = (num << 3) + (*(p++) - '0');
          break;

        case ST_HEX:            /* Hex sequence */
          switch (*p)
            {
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9':
              num = (num << 4) + (*(p++) - '0');
              break;
            case 'a':
            case 'b':
            case 'c':
            case 'd':
            case 'e':
            case 'f':
              num = (num << 4) + (*(p++) - 'a') + 10;
              break;
            case 'A':
            case 'B':
            case 'C':
            case 'D':
            case 'E':
            case 'F':
              num = (num << 4) + (*(p++) - 'A') + 10;
              break;
            default:
              *(q++) = num;
              ++count;
              state = ST_GND;
              break;
            }
          break;

        case ST_CARET:          /* Caret escape */
          state = ST_GND;       /* Should be the next state... */
          if (*p >= '@' && *p <= '~')
            {
              *(q++) = *(p++) & 037;
              ++count;
            }
          else if (*p == '?')
            {
              *(q++) = 127;
              ++count;
            }
          else
            state = ST_ERROR;
          break;

        default:
          abort ();
        }
    }

  *dest = q;
  *src = p;
  *output_count = count;

  return state != ST_ERROR;
}

static void
parse_ls_color (void)
{
  const char *p;                /* Pointer to character being parsed */
  char *buf;                    /* color_buf buffer pointer */
  int state;                    /* State of parser */
  int ind_no;                   /* Indicator number */
  char label[3];                /* Indicator label */
  struct color_ext_type *ext;   /* Extension we are working on */

  if ((p = getenv ("LS_COLORS")) == NULL || *p == '\0')
    return;

  ext = NULL;
  strcpy (label, "??");

  /* This is an overly conservative estimate, but any possible
     LS_COLORS string will *not* generate a color_buf longer than
     itself, so it is a safe way of allocating a buffer in
     advance.  */
  buf = color_buf = xstrdup (p);

  state = 1;
  while (state > 0)
    {
      switch (state)
        {
        case 1:         /* First label character */
          switch (*p)
            {
            case ':':
              ++p;
              break;

            case '*':
              /* Allocate new extension block and add to head of
                 linked list (this way a later definition will
                 override an earlier one, which can be useful for
                 having terminal-specific defs override global).  */

              ext = xmalloc (sizeof *ext);
              ext->next = color_ext_list;
              color_ext_list = ext;

              ++p;
              ext->ext.string = buf;

              state = (get_funky_string (&buf, &p, true, &ext->ext.len)
                       ? 4 : -1);
              break;

            case '\0':
              state = 0;        /* Done! */
              break;

            default:    /* Assume it is file type label */
              label[0] = *(p++);
              state = 2;
              break;
            }
          break;

        case 2:         /* Second label character */
          if (*p)
            {
              label[1] = *(p++);
              state = 3;
            }
          else
            state = -1; /* Error */
          break;

        case 3:         /* Equal sign after indicator label */
          state = -1;   /* Assume failure... */
          if (*(p++) == '=')/* It *should* be... */
            {
              for (ind_no = 0; indicator_name[ind_no] != NULL; ++ind_no)
                {
                  if (STREQ (label, indicator_name[ind_no]))
                    {
                      color_indicator[ind_no].string = buf;
                      state = (get_funky_string (&buf, &p, false,
                                                 &color_indicator[ind_no].len)
                               ? 1 : -1);
                      break;
                    }
                }
              if (state == -1)
                error (0, 0, _("unrecognized prefix: %s"), quotearg (label));
            }
         break;

        case 4:         /* Equal sign after *.ext */
          if (*(p++) == '=')
            {
              ext->seq.string = buf;
              state = (get_funky_string (&buf, &p, false, &ext->seq.len)
                       ? 1 : -1);
            }
          else
            state = -1;
          break;
        }
    }

  if (state < 0)
    {
      struct color_ext_type *e;
      struct color_ext_type *e2;

      error (0, 0,
             _("unparsable value for LS_COLORS environment variable"));
      free (color_buf);
      for (e = color_ext_list; e != NULL; /* empty */)
        {
          e2 = e;
          e = e->next;
          free (e2);
        }
      print_with_color = 0;
    }

  if (color_indicator[C_LINK].len == 6
      && !strncmp (color_indicator[C_LINK].string, "target", 6))
    color_symlink_as_referent = 1;
}

/* Request that the directory named NAME have its contents listed later.
   If REALNAME is nonzero, it will be used instead of NAME when the
   directory name is printed.  This allows symbolic links to directories
   to be treated as regular directories but still be listed under their
   real names.  NAME == NULL is used to insert a marker entry for the
   directory named in REALNAME.
   If F is non-NULL, we use its dev/ino information to save
   a call to stat -- when doing a recursive (-R) traversal.  */

static void
queue_directory (const char *name, const char *realname)
{
  struct pending *new;

  new = xmalloc (sizeof *new);
  new->realname = realname ? xstrdup (realname) : NULL;
  new->name = name ? xstrdup (name) : NULL;
  new->next = pending_dirs;
  pending_dirs = new;
}

/* Read directory `name', and list the files in it.
   If `realname' is nonzero, print its name instead of `name';
   this is used for symbolic links to directories. */

static void
print_dir (const char *name, const char *realname)
{
  register DIR *dirp;
  register struct dirent *next;
  register uintmax_t total_blocks = 0;
  static int first = 1;

  errno = 0;
  dirp = opendir (name);
  if (!dirp)
    {
      error (0, errno, "%s", quotearg_colon (name));
      exit_status = 1;
      return;
    }

  if (LOOP_DETECT)
    {
      struct stat dir_stat;
      int fd = dirfd (dirp);

      /* If dirfd failed, endure the overhead of using stat.  */
      if ((0 <= fd
           ? fstat (fd, &dir_stat)
           : stat (name, &dir_stat)) < 0)
        {
          error (0, errno, _("cannot determine device and inode of %s"),
                 quotearg_colon (name));
          exit_status = 1;
          return;
        }

      /* If we've already visited this dev/inode pair, warn that
         we've found a loop, and do not process this directory.  */
      if (visit_dir (dir_stat.st_dev, dir_stat.st_ino))
        {
          error (0, 0, _("not listing already-listed directory: %s"),
                 quotearg_colon (name));
          return;
        }

      DEV_INO_PUSH (dir_stat.st_dev, dir_stat.st_ino);
    }

  /* Read the directory entries, and insert the subfiles into the `files'
     table.  */

  clear_files ();

  while (1)
    {
      /* Set errno to zero so we can distinguish between a readdir failure
         and when readdir simply finds that there are no more entries.  */
      errno = 0;
      if ((next = readdir (dirp)) == NULL)
        {
          if (errno)
            {
              /* Save/restore errno across closedir call.  */
              int e = errno;
              closedir (dirp);
              errno = e;

              /* Arrange to give a diagnostic after exiting this loop.  */
              dirp = NULL;
            }
          break;
        }

      if (file_interesting (next))
        {
          enum filetype type = unknown;

#if HAVE_STRUCT_DIRENT_D_TYPE
          if (next->d_type == DT_BLK
              || next->d_type == DT_CHR
              || next->d_type == DT_DIR
              || next->d_type == DT_FIFO
              || next->d_type == DT_LNK
              || next->d_type == DT_REG
              || next->d_type == DT_SOCK)
            type = next->d_type;
#endif
          total_blocks += gobble_file (next->d_name, type, 0, name);
        }
    }

  if (dirp == NULL || CLOSEDIR (dirp))
    {
      error (0, errno, _("reading directory %s"), quotearg_colon (name));
      exit_status = 1;
      /* Don't return; print whatever we got. */
    }

  /* Sort the directory contents.  */
  sort_files ();

  /* If any member files are subdirectories, perhaps they should have their
     contents listed rather than being mentioned here as files.  */

  if (recursive)
    extract_dirs_from_files (name, 1);

  if (recursive || print_dir_name)
    {
      if (!first)
        DIRED_PUTCHAR ('\n');
      first = 0;
      DIRED_INDENT ();
      PUSH_CURRENT_DIRED_POS (&subdired_obstack);
      dired_pos += quote_name (stdout, realname ? realname : name,
                               dirname_quoting_options, NULL);
      PUSH_CURRENT_DIRED_POS (&subdired_obstack);
      DIRED_FPUTS_LITERAL (":\n", stdout);
    }

  if (format == long_format || print_block_size)
    {
      const char *p;
      char buf[LONGEST_HUMAN_READABLE + 1];

      DIRED_INDENT ();
      p = _("total");
      DIRED_FPUTS (p, stdout, strlen (p));
      DIRED_PUTCHAR (' ');
      p = human_readable (total_blocks, buf, human_output_opts,
                          ST_NBLOCKSIZE, output_block_size);
      DIRED_FPUTS (p, stdout, strlen (p));
      DIRED_PUTCHAR ('\n');
    }

  if (files_index)
    print_current_files ();
}

/* Add `pattern' to the list of patterns for which files that match are
   not listed.  */

static void
add_ignore_pattern (const char *pattern)
{
  register struct ignore_pattern *ignore;

  ignore = xmalloc (sizeof *ignore);
  ignore->pattern = pattern;
  /* Add it to the head of the linked list. */
  ignore->next = ignore_patterns;
  ignore_patterns = ignore;
}

/* Return nonzero if the file in `next' should be listed. */

static int
file_interesting (const struct dirent *next)
{
  register struct ignore_pattern *ignore;

  for (ignore = ignore_patterns; ignore; ignore = ignore->next)
    if (fnmatch (ignore->pattern, next->d_name, FNM_PERIOD) == 0)
      return 0;

  if (really_all_files
      || next->d_name[0] != '.'
      || (all_files
          && next->d_name[1] != '\0'
          && (next->d_name[1] != '.' || next->d_name[2] != '\0')))
    return 1;

  return 0;
}

/* POSIX requires that a file size be printed without a sign, even
   when negative.  Assume the typical case where negative sizes are
   actually positive values that have wrapped around.  */

static uintmax_t
unsigned_file_size (off_t size)
{
  return size + (size < 0) * ((uintmax_t) OFF_T_MAX - OFF_T_MIN + 1);
}

/* Enter and remove entries in the table `files'.  */

/* Empty the table of files. */

static void
clear_files (void)
{
  register size_t i;

  for (i = 0; i < files_index; i++)
    {
      free (files[i].name);
      if (files[i].linkname)
        free (files[i].linkname);
    }

  files_index = 0;
  inode_number_width = 0;
  block_size_width = 0;
  nlink_width = 0;
  owner_width = 0;
  group_width = 0;
  author_width = 0;
  major_device_number_width = 0;
  minor_device_number_width = 0;
  file_size_width = 0;
}

/* Add a file to the current table of files.
   Verify that the file exists, and print an error message if it does not.
   Return the number of blocks that the file occupies.  */

static uintmax_t
gobble_file (const char *name, enum filetype type, int explicit_arg,
             const char *dirname)
{
  register uintmax_t blocks;
  register char *path;
  register struct fileinfo *f;

  if (files_index == nfiles)
    {
      files = xnrealloc (files, nfiles, 2 * sizeof *files);
      nfiles *= 2;
    }

  f = &files[files_index];
  f->linkname = 0;
  f->linkmode = 0;
  f->linkok = 0;

  if (explicit_arg
      || format_needs_stat
      || (format_needs_type
          && (type == unknown

              /* FIXME: remove this disjunct.
                 I don't think we care about symlinks here, but for now
                 this won't make a big performance difference.  */
              || type == symbolic_link

              /* --indicator-style=classify (aka -F)
                 requires that we stat each regular file
                 to see if it's executable.  */
              || (type == normal && (indicator_style == classify
                                     /* This is so that --color ends up
                                        highlighting files with the executable
                                        bit set even when options like -F are
                                        not specified.  */
                                     || print_with_color)))))

    {
      /* `path' is the absolute pathname of this file. */
      int err;

      if (name[0] == '/' || dirname[0] == 0)
        path = (char *) name;
      else
        {
          path = alloca (strlen (name) + strlen (dirname) + 2);
          attach (path, dirname, name);
        }

      switch (dereference)
        {
        case DEREF_ALWAYS:
          err = stat (path, &f->stat);
          break;

        case DEREF_COMMAND_LINE_ARGUMENTS:
        case DEREF_COMMAND_LINE_SYMLINK_TO_DIR:
          if (explicit_arg)
            {
              int need_lstat;
              err = stat (path, &f->stat);

              if (dereference == DEREF_COMMAND_LINE_ARGUMENTS)
                break;

              need_lstat = (err < 0
                            ? errno == ENOENT
                            : ! S_ISDIR (f->stat.st_mode));
              if (!need_lstat)
                break;

              /* stat failed because of ENOENT, maybe indicating a dangling
                 symlink.  Or stat succeeded, PATH does not refer to a
                 directory, and --dereference-command-line-symlink-to-dir is
                 in effect.  Fall through so that we call lstat instead.  */
            }

        default: /* DEREF_NEVER */
          err = lstat (path, &f->stat);
          break;
        }

      if (err < 0)
        {
          error (0, errno, "%s", quotearg_colon (path));
          exit_status = 1;
          return 0;
        }

#if HAVE_ACL
      if (format == long_format)
        {
          int n = file_has_acl (path, &f->stat);
          f->have_acl = (0 < n);
          if (n < 0)
            error (0, errno, "%s", quotearg_colon (path));
        }
#endif

      if (S_ISLNK (f->stat.st_mode)
          && (format == long_format || check_symlink_color))
        {
          char *linkpath;
          struct stat linkstats;

          get_link_name (path, f);
          linkpath = make_link_path (path, f->linkname);

          /* Avoid following symbolic links when possible, ie, when
             they won't be traced and when no indicator is needed. */
          if (linkpath
              && (indicator_style != none || check_symlink_color)
              && stat (linkpath, &linkstats) == 0)
            {
              f->linkok = 1;

              /* Symbolic links to directories that are mentioned on the
                 command line are automatically traced if not being
                 listed as files.  */
              if (!explicit_arg || format == long_format
                  || !S_ISDIR (linkstats.st_mode))
                {
                  /* Get the linked-to file's mode for the filetype indicator
                     in long listings.  */
                  f->linkmode = linkstats.st_mode;
                  f->linkok = 1;
                }
            }
          if (linkpath)
            free (linkpath);
        }

      if (S_ISLNK (f->stat.st_mode))
        f->filetype = symbolic_link;
      else if (S_ISDIR (f->stat.st_mode))
        {
          if (explicit_arg && !immediate_dirs)
            f->filetype = arg_directory;
          else
            f->filetype = directory;
        }
      else
        f->filetype = normal;

      {
        char buf[INT_BUFSIZE_BOUND (uintmax_t)];
        int len = strlen (umaxtostr (f->stat.st_ino, buf));
        if (inode_number_width < len)
          inode_number_width = len;
      }

      blocks = ST_NBLOCKS (f->stat);
      {
        char buf[LONGEST_HUMAN_READABLE + 1];
        int len = strlen (human_readable (blocks, buf, human_output_opts,
                                          ST_NBLOCKSIZE, output_block_size));
        if (block_size_width < len)
          block_size_width = len;
      }

      if (print_owner)
        {
          int len = format_user_width (f->stat.st_uid);
          if (owner_width < len)
            owner_width = len;
        }

      if (print_group)
        {
          int len = format_group_width (f->stat.st_gid);
          if (group_width < len)
            group_width = len;
        }

      if (print_author)
        {
          int len = format_user_width (f->stat.st_uid);
          if (author_width < len)
            author_width = len;
        }

      {
        char buf[INT_BUFSIZE_BOUND (uintmax_t)];
        int len = strlen (umaxtostr (f->stat.st_nlink, buf));
        if (nlink_width < len)
          nlink_width = len;
      }

      if (S_ISCHR (f->stat.st_mode) || S_ISBLK (f->stat.st_mode))
        {
          char buf[INT_BUFSIZE_BOUND (uintmax_t)];
          int len = strlen (umaxtostr (major (f->stat.st_rdev), buf));
          if (major_device_number_width < len)
            major_device_number_width = len;
          len = strlen (umaxtostr (minor (f->stat.st_rdev), buf));
          if (minor_device_number_width < len)
            minor_device_number_width = len;
          len = major_device_number_width + 2 + minor_device_number_width;
          if (file_size_width < len)
            file_size_width = len;
        }
      else
        {
          char buf[LONGEST_HUMAN_READABLE + 1];
          uintmax_t size = unsigned_file_size (f->stat.st_size);
          int len = strlen (human_readable (size, buf, human_output_opts,
                                            1, file_output_block_size));
          if (file_size_width < len)
            file_size_width = len;
        }
    }
  else
    {
      f->filetype = type;
#if HAVE_STRUCT_DIRENT_D_TYPE
      f->stat.st_mode = DTTOIF (type);
#endif
      blocks = 0;
    }

  f->name = xstrdup (name);
  files_index++;

  return blocks;
}

#ifdef S_ISLNK

/* Put the name of the file that `filename' is a symbolic link to
   into the `linkname' field of `f'. */

static void
get_link_name (const char *filename, struct fileinfo *f)
{
  f->linkname = xreadlink (filename);
  if (f->linkname == NULL)
    {
      error (0, errno, _("cannot read symbolic link %s"),
             quotearg_colon (filename));
      exit_status = 1;
    }
}

/* If `linkname' is a relative path and `path' contains one or more
   leading directories, return `linkname' with those directories
   prepended; otherwise, return a copy of `linkname'.
   If `linkname' is zero, return zero. */

static char *
make_link_path (const char *path, const char *linkname)
{
  char *linkbuf;
  size_t bufsiz;

  if (linkname == 0)
    return 0;

  if (*linkname == '/')
    return xstrdup (linkname);

  /* The link is to a relative path.  Prepend any leading path
     in `path' to the link name. */
  linkbuf = strrchr (path, '/');
  if (linkbuf == 0)
    return xstrdup (linkname);

  bufsiz = linkbuf - path + 1;
  linkbuf = xmalloc (bufsiz + strlen (linkname) + 1);
  strncpy (linkbuf, path, bufsiz);
  strcpy (linkbuf + bufsiz, linkname);
  return linkbuf;
}
#endif

/* Return nonzero if base_name (NAME) ends in `.' or `..'
   This is so we don't try to recurse on `././././. ...' */

static int
basename_is_dot_or_dotdot (const char *name)
{
  char const *base = base_name (name);
  return DOT_OR_DOTDOT (base);
}

/* Remove any entries from `files' that are for directories,
   and queue them to be listed as directories instead.
   `dirname' is the prefix to prepend to each dirname
   to make it correct relative to ls's working dir.
   If IGNORE_DOT_AND_DOT_DOT is nonzero don't treat `.' and `..' as dirs.
   This is desirable when processing directories recursively.  */

static void
extract_dirs_from_files (const char *dirname, int ignore_dot_and_dot_dot)
{
  register size_t i;
  register size_t j;

  if (*dirname && LOOP_DETECT)
    {
      /* Insert a marker entry first.  When we dequeue this marker entry,
         we'll know that DIRNAME has been processed and may be removed
         from the set of active directories.  */
      queue_directory (NULL, dirname);
    }

  /* Queue the directories last one first, because queueing reverses the
     order.  */
  for (i = files_index; i-- != 0; )
    if ((files[i].filetype == directory || files[i].filetype == arg_directory)
        && (!ignore_dot_and_dot_dot
            || !basename_is_dot_or_dotdot (files[i].name)))
      {
        if (files[i].name[0] == '/' || dirname[0] == 0)
          {
            queue_directory (files[i].name, files[i].linkname);
          }
        else
          {
            char *path = path_concat (dirname, files[i].name, NULL);
            queue_directory (path, files[i].linkname);
            free (path);
          }
        if (files[i].filetype == arg_directory)
          free (files[i].name);
      }

  /* Now delete the directories from the table, compacting all the remaining
     entries.  */

  for (i = 0, j = 0; i < files_index; i++)
    {
      if (files[i].filetype != arg_directory)
        {
          if (j < i)
            files[j] = files[i];
          ++j;
        }
    }
  files_index = j;
}

/* Use strcoll to compare strings in this locale.  If an error occurs,
   report an error and longjmp to failed_strcoll.  */

static jmp_buf failed_strcoll;

static int
xstrcoll (char const *a, char const *b)
{
  int diff;
  errno = 0;
  diff = strcoll (a, b);
  if (errno)
    {
      error (0, errno, _("cannot compare file names %s and %s"),
             quote_n (0, a), quote_n (1, b));
      exit_status = 1;
      longjmp (failed_strcoll, 1);
    }
  return diff;
}

/* Comparison routines for sorting the files. */

typedef void const *V;

static inline int
cmp_ctime (struct fileinfo const *a, struct fileinfo const *b,
           int (*cmp) (char const *, char const *))
{
  int diff = CTIME_CMP (b->stat, a->stat);
  return diff ? diff : cmp (a->name, b->name);
}
static int compare_ctime (V a, V b) { return cmp_ctime (a, b, xstrcoll); }
static int compstr_ctime (V a, V b) { return cmp_ctime (a, b, strcmp); }
static int rev_cmp_ctime (V a, V b) { return compare_ctime (b, a); }
static int rev_str_ctime (V a, V b) { return compstr_ctime (b, a); }

static inline int
cmp_mtime (struct fileinfo const *a, struct fileinfo const *b,
           int (*cmp) (char const *, char const *))
{
  int diff = MTIME_CMP (b->stat, a->stat);
  return diff ? diff : cmp (a->name, b->name);
}
static int compare_mtime (V a, V b) { return cmp_mtime (a, b, xstrcoll); }
static int compstr_mtime (V a, V b) { return cmp_mtime (a, b, strcmp); }
static int rev_cmp_mtime (V a, V b) { return compare_mtime (b, a); }
static int rev_str_mtime (V a, V b) { return compstr_mtime (b, a); }

static inline int
cmp_atime (struct fileinfo const *a, struct fileinfo const *b,
           int (*cmp) (char const *, char const *))
{
  int diff = ATIME_CMP (b->stat, a->stat);
  return diff ? diff : cmp (a->name, b->name);
}
static int compare_atime (V a, V b) { return cmp_atime (a, b, xstrcoll); }
static int compstr_atime (V a, V b) { return cmp_atime (a, b, strcmp); }
static int rev_cmp_atime (V a, V b) { return compare_atime (b, a); }
static int rev_str_atime (V a, V b) { return compstr_atime (b, a); }

static inline int
cmp_size (struct fileinfo const *a, struct fileinfo const *b,
          int (*cmp) (char const *, char const *))
{
  int diff = longdiff (b->stat.st_size, a->stat.st_size);
  return diff ? diff : cmp (a->name, b->name);
}
static int compare_size (V a, V b) { return cmp_size (a, b, xstrcoll); }
static int compstr_size (V a, V b) { return cmp_size (a, b, strcmp); }
static int rev_cmp_size (V a, V b) { return compare_size (b, a); }
static int rev_str_size (V a, V b) { return compstr_size (b, a); }

static inline int
cmp_version (struct fileinfo const *a, struct fileinfo const *b)
{
  return strverscmp (a->name, b->name);
}
static int compare_version (V a, V b) { return cmp_version (a, b); }
static int rev_cmp_version (V a, V b) { return compare_version (b, a); }

static inline int
cmp_name (struct fileinfo const *a, struct fileinfo const *b,
          int (*cmp) (char const *, char const *))
{
  return cmp (a->name, b->name);
}
static int compare_name (V a, V b) { return cmp_name (a, b, xstrcoll); }
static int compstr_name (V a, V b) { return cmp_name (a, b, strcmp); }
static int rev_cmp_name (V a, V b) { return compare_name (b, a); }
static int rev_str_name (V a, V b) { return compstr_name (b, a); }

/* Compare file extensions.  Files with no extension are `smallest'.
   If extensions are the same, compare by filenames instead. */

static inline int
cmp_extension (struct fileinfo const *a, struct fileinfo const *b,
               int (*cmp) (char const *, char const *))
{
  char const *base1 = strrchr (a->name, '.');
  char const *base2 = strrchr (b->name, '.');
  int diff = cmp (base1 ? base1 : "", base2 ? base2 : "");
  return diff ? diff : cmp (a->name, b->name);
}
static int compare_extension (V a, V b) { return cmp_extension (a, b, xstrcoll); }
static int compstr_extension (V a, V b) { return cmp_extension (a, b, strcmp); }
static int rev_cmp_extension (V a, V b) { return compare_extension (b, a); }
static int rev_str_extension (V a, V b) { return compstr_extension (b, a); }

/* Sort the files now in the table.  */

static void
sort_files (void)
{
  /* `func' must be `volatile', so it can't be
     clobbered by a `longjmp' into this function.  */
  int (* volatile func) (V, V);

  switch (sort_type)
    {
    case sort_none:
      return;
    case sort_time:
      switch (time_type)
        {
        case time_ctime:
          func = sort_reverse ? rev_cmp_ctime : compare_ctime;
          break;
        case time_mtime:
          func = sort_reverse ? rev_cmp_mtime : compare_mtime;
          break;
        case time_atime:
          func = sort_reverse ? rev_cmp_atime : compare_atime;
          break;
        default:
          abort ();
        }
      break;
    case sort_name:
      func = sort_reverse ? rev_cmp_name : compare_name;
      break;
    case sort_extension:
      func = sort_reverse ? rev_cmp_extension : compare_extension;
      break;
    case sort_size:
      func = sort_reverse ? rev_cmp_size : compare_size;
      break;
    case sort_version:
      func = sort_reverse ? rev_cmp_version : compare_version;
      break;
    default:
      abort ();
    }

  /* Try strcoll.  If it fails, fall back on strcmp.  We can't safely
     ignore strcoll failures, as a failing strcoll might be a
     comparison function that is not a total order, and if we ignored
     the failure this might cause qsort to dump core.  */

  if (setjmp (failed_strcoll))
    {
      switch (sort_type)
        {
        case sort_time:
          switch (time_type)
            {
            case time_ctime:
              func = sort_reverse ? rev_str_ctime : compstr_ctime;
              break;
            case time_mtime:
              func = sort_reverse ? rev_str_mtime : compstr_mtime;
              break;
            case time_atime:
              func = sort_reverse ? rev_str_atime : compstr_atime;
              break;
            default:
              abort ();
            }
          break;
        case sort_name:
          func = sort_reverse ? rev_str_name : compstr_name;
          break;
        case sort_extension:
          func = sort_reverse ? rev_str_extension : compstr_extension;
          break;
        case sort_size:
          func = sort_reverse ? rev_str_size : compstr_size;
          break;
        default:
          abort ();
        }
    }

  qsort (files, files_index, sizeof (struct fileinfo), func);
}

/* List all the files now in the table.  */

static void
print_current_files (void)
{
  register size_t i;

  switch (format)
    {
    case one_per_line:
      for (i = 0; i < files_index; i++)
        {
          print_file_name_and_frills (files + i);
          putchar ('\n');
        }
      break;

    case many_per_line:
      print_many_per_line ();
      break;

    case horizontal:
      print_horizontal ();
      break;

    case with_commas:
      print_with_commas ();
      break;

    case long_format:
      for (i = 0; i < files_index; i++)
        {
          print_long_format (files + i);
          DIRED_PUTCHAR ('\n');
        }
      break;
    }
}

/* Return the expected number of columns in a long-format time stamp,
   or zero if it cannot be calculated.  */

static int
long_time_expected_width (void)
{
  static int width = -1;

  if (width < 0)
    {
      time_t epoch = 0;
      struct tm const *tm = localtime (&epoch);
      char const *fmt = long_time_format[0];
      char initbuf[100];
      char *buf = initbuf;
      size_t bufsize = sizeof initbuf;
      size_t len;

      for (;;)
        {
          *buf = '\1';
          len = nstrftime (buf, bufsize, fmt, tm, 0, 0);
          if (len || ! *buf)
            break;
          buf = alloca (bufsize *= 2);
        }

      width = mbsnwidth (buf, len, 0);
      if (width < 0)
        width = 0;
    }

  return width;
}

/* Get the current time.  */

static void
get_current_time (void)
{
#if HAVE_CLOCK_GETTIME && defined CLOCK_REALTIME
  {
    struct timespec timespec;
    if (clock_gettime (CLOCK_REALTIME, &timespec) == 0)
      {
        current_time = timespec.tv_sec;
        current_time_ns = timespec.tv_nsec;
        return;
      }
  }
#endif

  /* The clock does not have nanosecond resolution, so get the maximum
     possible value for the current time that is consistent with the
     reported clock.  That way, files are not considered to be in the
     future merely because their time stamps have higher resolution
     than the clock resolution.  */

#if HAVE_GETTIMEOFDAY
  {
    struct timeval timeval;
    if (gettimeofday (&timeval, NULL) == 0)
      {
        current_time = timeval.tv_sec;
        current_time_ns = timeval.tv_usec * 1000 + 999;
        return;
      }
  }
#endif

  current_time = time (NULL);
  current_time_ns = 999999999;
}

/* Print the name or id of the user with id U, using a print width of
   WIDTH.  */

static void
format_user (uid_t u, int width)
{
  char const *name = (numeric_ids ? NULL : getuser (u));
  if (name)
    printf ("%-*s ", width, name);
  else
    printf ("%*lu ", width, (unsigned long int) u);
  dired_pos += width;
  dired_pos++;
}

/* Likewise, for groups.  */

static void
format_group (gid_t g, int width)
{
  char const *name = (numeric_ids ? NULL : getgroup (g));
  if (name)
    printf ("%-*s ", width, name);
  else
    printf ("%*lu ", width, (unsigned long int) g);
  dired_pos += width;
  dired_pos++;
}

/* Return the number of bytes that format_user will print.  */

static int
format_user_width (uid_t u)
{
  char const *name = (numeric_ids ? NULL : getuser (u));
  char buf[INT_BUFSIZE_BOUND (unsigned long int)];
  size_t len;

  if (! name)
    {
      sprintf (buf, "%lu", (unsigned long int) u);
      name = buf;
    }

  len = strlen (name);
  if (INT_MAX < len)
    error (EXIT_FAILURE, 0, _("User name too long"));
  return len;
}

/* Likewise, for groups.  */

static int
format_group_width (gid_t g)
{
  char const *name = (numeric_ids ? NULL : getgroup (g));
  char buf[INT_BUFSIZE_BOUND (unsigned long int)];
  size_t len;

  if (! name)
    {
      sprintf (buf, "%lu", (unsigned long int) g);
      name = buf;
    }

  len = strlen (name);
  if (INT_MAX < len)
    error (EXIT_FAILURE, 0, _("Group name too long"));
  return len;
}


/* Print information about F in long format.  */

static void
print_long_format (const struct fileinfo *f)
{
  char modebuf[12];
  char init_bigbuf
    [LONGEST_HUMAN_READABLE + 1         /* inode */
     + LONGEST_HUMAN_READABLE + 1       /* size in blocks */
     + sizeof (modebuf) - 1 + 1         /* mode string */
     + INT_BUFSIZE_BOUND (uintmax_t)    /* st_nlink */
     + LONGEST_HUMAN_READABLE + 2       /* major device number */
     + LONGEST_HUMAN_READABLE + 1       /* minor device number */
     + 35 + 1   /* usual length of time/date -- may be longer; see below */
     ];
  char *buf = init_bigbuf;
  size_t bufsize = sizeof (init_bigbuf);
  size_t s;
  char *p;
  time_t when;
  int when_ns IF_LINT (= 0);
  struct tm *when_local;

  /* Compute mode string.  On most systems, it's based on st_mode.
     On systems with migration (via the stat.st_dm_mode field), use
     the file's migrated status.  */
  mode_string (ST_DM_MODE (f->stat), modebuf);

  modebuf[10] = (FILE_HAS_ACL (f) ? '+' : ' ');
  modebuf[11] = '\0';

  switch (time_type)
    {
    case time_ctime:
      when = f->stat.st_ctime;
      when_ns = TIMESPEC_NS (f->stat.st_ctim);
      break;
    case time_mtime:
      when = f->stat.st_mtime;
      when_ns = TIMESPEC_NS (f->stat.st_mtim);
      break;
    case time_atime:
      when = f->stat.st_atime;
      when_ns = TIMESPEC_NS (f->stat.st_atim);
      break;
    }

  p = buf;

  if (print_inode)
    {
      char hbuf[INT_BUFSIZE_BOUND (uintmax_t)];
      sprintf (p, "%*s ", inode_number_width,
               umaxtostr (f->stat.st_ino, hbuf));
      p += inode_number_width + 1;
    }

  if (print_block_size)
    {
      char hbuf[LONGEST_HUMAN_READABLE + 1];
      sprintf (p, "%*s ", block_size_width,
               human_readable (ST_NBLOCKS (f->stat), hbuf, human_output_opts,
                               ST_NBLOCKSIZE, output_block_size));
      p += block_size_width + 1;
    }

  /* The last byte of the mode string is the POSIX
     "optional alternate access method flag".  */
  {
    char hbuf[INT_BUFSIZE_BOUND (uintmax_t)];
    sprintf (p, "%s %*s ", modebuf, nlink_width,
             umaxtostr (f->stat.st_nlink, hbuf));
  }
  p += sizeof modebuf + nlink_width + 1;

  DIRED_INDENT ();

  if (print_owner | print_group | print_author)
    {
      DIRED_FPUTS (buf, stdout, p - buf);

      if (print_owner)
        format_user (f->stat.st_uid, owner_width);

      if (print_group)
        format_group (f->stat.st_gid, group_width);

      if (print_author)
        format_user (f->stat.st_author, author_width);

      p = buf;
    }

  if (S_ISCHR (f->stat.st_mode) || S_ISBLK (f->stat.st_mode))
    {
      char majorbuf[INT_BUFSIZE_BOUND (uintmax_t)];
      char minorbuf[INT_BUFSIZE_BOUND (uintmax_t)];
      int blanks_width = (file_size_width
                          - (major_device_number_width + 2
                             + minor_device_number_width));
      sprintf (p, "%*s, %*s ",
               major_device_number_width + MAX (0, blanks_width),
               umaxtostr (major (f->stat.st_rdev), majorbuf),
               minor_device_number_width,
               umaxtostr (minor (f->stat.st_rdev), minorbuf));
    }
  else
    {
      char hbuf[LONGEST_HUMAN_READABLE + 1];
      uintmax_t size = unsigned_file_size (f->stat.st_size);
      sprintf (p, "%*s ", file_size_width,
               human_readable (size, hbuf, human_output_opts,
                               1, file_output_block_size));
    }

  p += file_size_width + 1;

  if ((when_local = localtime (&when)))
    {
      time_t six_months_ago;
      int recent;
      char const *fmt;

      /* If the file appears to be in the future, update the current
         time, in case the file happens to have been modified since
         the last time we checked the clock.  */
      if (current_time < when
          || (current_time == when && current_time_ns < when_ns))
        {
          /* Note that get_current_time calls gettimeofday which, on some non-
             compliant systems, clobbers the buffer used for localtime's result.
             But it's ok here, because we use a gettimeofday wrapper that
             saves and restores the buffer around the gettimeofday call.  */
          get_current_time ();
        }

      /* Consider a time to be recent if it is within the past six
         months.  A Gregorian year has 365.2425 * 24 * 60 * 60 ==
         31556952 seconds on the average.  Write this value as an
         integer constant to avoid floating point hassles.  */
      six_months_ago = current_time - 31556952 / 2;
      recent = (six_months_ago <= when
                && (when < current_time
                    || (when == current_time && when_ns <= current_time_ns)));
      fmt = long_time_format[recent];

      for (;;)
        {
          char *newbuf;
          *p = '\1';
          s = nstrftime (p, buf + bufsize - p - 1, fmt,
                         when_local, 0, when_ns);
          if (s || ! *p)
            break;
          newbuf = alloca (bufsize *= 2);
          memcpy (newbuf, buf, p - buf);
          p = newbuf + (p - buf);
          buf = newbuf;
        }

      p += s;
      *p++ = ' ';

      /* NUL-terminate the string -- fputs (via DIRED_FPUTS) requires it.  */
      *p = '\0';
    }
  else
    {
      /* The time cannot be represented as a local time;
         print it as a huge integer number of seconds.  */
      char hbuf[INT_BUFSIZE_BOUND (intmax_t)];
      sprintf (p, "%*s ", long_time_expected_width (),
               (TYPE_SIGNED (time_t)
                ? imaxtostr (when, hbuf)
                : umaxtostr (when, hbuf)));
      p += strlen (p);
    }

  DIRED_FPUTS (buf, stdout, p - buf);
  print_name_with_quoting (f->name, FILE_OR_LINK_MODE (f), f->linkok,
                           &dired_obstack);

  if (f->filetype == symbolic_link)
    {
      if (f->linkname)
        {
          DIRED_FPUTS_LITERAL (" -> ", stdout);
          print_name_with_quoting (f->linkname, f->linkmode, f->linkok - 1,
                                   NULL);
          if (indicator_style != none)
            print_type_indicator (f->linkmode);
        }
    }
  else if (indicator_style != none)
    print_type_indicator (f->stat.st_mode);
}

/* Output to OUT a quoted representation of the file name NAME,
   using OPTIONS to control quoting.  Produce no output if OUT is NULL.
   Store the number of screen columns occupied by NAME's quoted
   representation into WIDTH, if non-NULL.  Return the number of bytes
   produced.  */

static size_t
quote_name (FILE *out, const char *name, struct quoting_options const *options,
            size_t *width)
{
  char smallbuf[BUFSIZ];
  size_t len = quotearg_buffer (smallbuf, sizeof smallbuf, name, -1, options);
  char *buf;
  size_t displayed_width IF_LINT (= 0);

  if (len < sizeof smallbuf)
    buf = smallbuf;
  else
    {
      buf = alloca (len + 1);
      quotearg_buffer (buf, len + 1, name, -1, options);
    }

  if (qmark_funny_chars)
    {
#if HAVE_MBRTOWC
      if (MB_CUR_MAX > 1)
        {
          char const *p = buf;
          char const *plimit = buf + len;
          char *q = buf;
          displayed_width = 0;

          while (p < plimit)
            switch (*p)
              {
                case ' ': case '!': case '"': case '#': case '%':
                case '&': case '\'': case '(': case ')': case '*':
                case '+': case ',': case '-': case '.': case '/':
                case '0': case '1': case '2': case '3': case '4':
                case '5': case '6': case '7': case '8': case '9':
                case ':': case ';': case '<': case '=': case '>':
                case '?':
                case 'A': case 'B': case 'C': case 'D': case 'E':
                case 'F': case 'G': case 'H': case 'I': case 'J':
                case 'K': case 'L': case 'M': case 'N': case 'O':
                case 'P': case 'Q': case 'R': case 'S': case 'T':
                case 'U': case 'V': case 'W': case 'X': case 'Y':
                case 'Z':
                case '[': case '\\': case ']': case '^': case '_':
                case 'a': case 'b': case 'c': case 'd': case 'e':
                case 'f': case 'g': case 'h': case 'i': case 'j':
                case 'k': case 'l': case 'm': case 'n': case 'o':
                case 'p': case 'q': case 'r': case 's': case 't':
                case 'u': case 'v': case 'w': case 'x': case 'y':
                case 'z': case '{': case '|': case '}': case '~':
                  /* These characters are printable ASCII characters.  */
                  *q++ = *p++;
                  displayed_width += 1;
                  break;
                default:
                  /* If we have a multibyte sequence, copy it until we
                     reach its end, replacing each non-printable multibyte
                     character with a single question mark.  */
                  {
                    mbstate_t mbstate;
                    memset (&mbstate, 0, sizeof mbstate);
                    do
                      {
                        wchar_t wc;
                        size_t bytes;
                        int w;

                        bytes = mbrtowc (&wc, p, plimit - p, &mbstate);

                        if (bytes == (size_t) -1)
                          {
                            /* An invalid multibyte sequence was
                               encountered.  Skip one input byte, and
                               put a question mark.  */
                            p++;
                            *q++ = '?';
                            displayed_width += 1;
                            break;
                          }

                        if (bytes == (size_t) -2)
                          {
                            /* An incomplete multibyte character
                               at the end.  Replace it entirely with
                               a question mark.  */
                            p = plimit;
                            *q++ = '?';
                            displayed_width += 1;
                            break;
                          }

                        if (bytes == 0)
                          /* A null wide character was encountered.  */
                          bytes = 1;

                        w = wcwidth (wc);
                        if (w >= 0)
                          {
                            /* A printable multibyte character.
                               Keep it.  */
                            for (; bytes > 0; --bytes)
                              *q++ = *p++;
                            displayed_width += w;
                          }
                        else
                          {
                            /* An unprintable multibyte character.
                               Replace it entirely with a question
                               mark.  */
                            p += bytes;
                            *q++ = '?';
                            displayed_width += 1;
                          }
                      }
                    while (! mbsinit (&mbstate));
                  }
                  break;
              }

          /* The buffer may have shrunk.  */
          len = q - buf;
        }
      else
#endif
        {
          char *p = buf;
          char const *plimit = buf + len;

          while (p < plimit)
            {
              if (! ISPRINT ((unsigned char) *p))
                *p = '?';
              p++;
            }
          displayed_width = len;
        }
    }
  else if (width != NULL)
    {
#if HAVE_MBRTOWC
      if (MB_CUR_MAX > 1)
        displayed_width = mbsnwidth (buf, len, 0);
      else
#endif
        {
          char const *p = buf;
          char const *plimit = buf + len;

          displayed_width = 0;
          while (p < plimit)
            {
              if (ISPRINT ((unsigned char) *p))
                displayed_width++;
              p++;
            }
        }
    }

  if (out != NULL)
    fwrite (buf, 1, len, out);
  if (width != NULL)
    *width = displayed_width;
  return len;
}

static void
print_name_with_quoting (const char *p, mode_t mode, int linkok,
                         struct obstack *stack)
{
  if (print_with_color)
    print_color_indicator (p, mode, linkok);

  if (stack)
    PUSH_CURRENT_DIRED_POS (stack);

  dired_pos += quote_name (stdout, p, filename_quoting_options, NULL);

  if (stack)
    PUSH_CURRENT_DIRED_POS (stack);

  if (print_with_color)
    prep_non_filename_text ();
}

static void
prep_non_filename_text (void)
{
  if (color_indicator[C_END].string != NULL)
    put_indicator (&color_indicator[C_END]);
  else
    {
      put_indicator (&color_indicator[C_LEFT]);
      put_indicator (&color_indicator[C_NORM]);
      put_indicator (&color_indicator[C_RIGHT]);
    }
}

/* Print the file name of `f' with appropriate quoting.
   Also print file size, inode number, and filetype indicator character,
   as requested by switches.  */

static void
print_file_name_and_frills (const struct fileinfo *f)
{
  char buf[MAX (LONGEST_HUMAN_READABLE + 1, INT_BUFSIZE_BOUND (uintmax_t))];

  if (print_inode)
    printf ("%*s ", format == with_commas ? 0 : inode_number_width,
            umaxtostr (f->stat.st_ino, buf));

  if (print_block_size)
    printf ("%*s ", format == with_commas ? 0 : block_size_width,
            human_readable (ST_NBLOCKS (f->stat), buf, human_output_opts,
                            ST_NBLOCKSIZE, output_block_size));

  print_name_with_quoting (f->name, FILE_OR_LINK_MODE (f), f->linkok, NULL);

  if (indicator_style != none)
    print_type_indicator (f->stat.st_mode);
}

static void
print_type_indicator (mode_t mode)
{
  int c;

  if (S_ISREG (mode))
    {
      if (indicator_style == classify && (mode & S_IXUGO))
        c ='*';
      else
        c = 0;
    }
  else
    {
      if (S_ISDIR (mode))
        c = '/';
      else if (S_ISLNK (mode))
        c = '@';
      else if (S_ISFIFO (mode))
        c = '|';
      else if (S_ISSOCK (mode))
        c = '=';
      else if (S_ISDOOR (mode))
        c = '>';
      else
        c = 0;
    }

  if (c)
    DIRED_PUTCHAR (c);
}

static void
print_color_indicator (const char *name, mode_t mode, int linkok)
{
  int type = C_FILE;
  struct color_ext_type *ext;   /* Color extension */
  size_t len;                   /* Length of name */

  /* Is this a nonexistent file?  If so, linkok == -1.  */

  if (linkok == -1 && color_indicator[C_MISSING].string != NULL)
    {
      ext = NULL;
      type = C_MISSING;
    }
  else
    {
      if (S_ISDIR (mode))
        type = C_DIR;
      else if (S_ISLNK (mode))
        type = ((!linkok && color_indicator[C_ORPHAN].string)
                ? C_ORPHAN : C_LINK);
      else if (S_ISFIFO (mode))
        type = C_FIFO;
      else if (S_ISSOCK (mode))
        type = C_SOCK;
      else if (S_ISBLK (mode))
        type = C_BLK;
      else if (S_ISCHR (mode))
        type = C_CHR;
      else if (S_ISDOOR (mode))
        type = C_DOOR;

      if (type == C_FILE && (mode & S_IXUGO) != 0)
        type = C_EXEC;

      /* Check the file's suffix only if still classified as C_FILE.  */
      ext = NULL;
      if (type == C_FILE)
        {
          /* Test if NAME has a recognized suffix.  */

          len = strlen (name);
          name += len;          /* Pointer to final \0.  */
          for (ext = color_ext_list; ext != NULL; ext = ext->next)
            {
              if (ext->ext.len <= len
                  && strncmp (name - ext->ext.len, ext->ext.string,
                              ext->ext.len) == 0)
                break;
            }
        }
    }

  put_indicator (&color_indicator[C_LEFT]);
  put_indicator (ext ? &(ext->seq) : &color_indicator[type]);
  put_indicator (&color_indicator[C_RIGHT]);
}

/* Output a color indicator (which may contain nulls).  */
static void
put_indicator (const struct bin_str *ind)
{
  register size_t i;
  register const char *p;

  p = ind->string;

  for (i = ind->len; i != 0; --i)
    putchar (*(p++));
}

/* Output a color indicator, but don't use stdio, for use from signal handlers.
   Return zero if the write is successful or if the string length is zero.
   Return nonzero if the write fails.  */
static int
put_indicator_direct (const struct bin_str *ind)
{
  size_t len;
  if (ind->len == 0)
    return 0;

  len = ind->len;
  return (full_write (STDOUT_FILENO, ind->string, len) != len);
}

static size_t
length_of_file_name_and_frills (const struct fileinfo *f)
{
  register size_t len = 0;
  size_t name_width;
  char buf[MAX (LONGEST_HUMAN_READABLE + 1, INT_BUFSIZE_BOUND (uintmax_t))];

  if (print_inode)
    len += 1 + (format == with_commas
                ? strlen (umaxtostr (f->stat.st_ino, buf))
                : inode_number_width);

  if (print_block_size)
    len += 1 + (format == with_commas
                ? strlen (human_readable (ST_NBLOCKS (f->stat), buf,
                                          human_output_opts, ST_NBLOCKSIZE,
                                          output_block_size))
                : block_size_width);

  quote_name (NULL, f->name, filename_quoting_options, &name_width);
  len += name_width;

  if (indicator_style != none)
    {
      mode_t filetype = f->stat.st_mode;

      if (S_ISREG (filetype))
        {
          if (indicator_style == classify
              && (f->stat.st_mode & S_IXUGO))
            len += 1;
        }
      else if (S_ISDIR (filetype)
               || S_ISLNK (filetype)
               || S_ISFIFO (filetype)
               || S_ISSOCK (filetype)
               || S_ISDOOR (filetype)
               )
        len += 1;
    }

  return len;
}

static void
print_many_per_line (void)
{
  size_t row;                   /* Current row. */
  size_t cols = calculate_columns (true);
  struct column_info const *line_fmt = &column_info[cols - 1];

  /* Calculate the number of rows that will be in each column except possibly
     for a short column on the right. */
  size_t rows = files_index / cols + (files_index % cols != 0);

  for (row = 0; row < rows; row++)
    {
      size_t col = 0;
      size_t filesno = row;
      size_t pos = 0;

      /* Print the next row.  */
      while (1)
        {
          size_t name_length = length_of_file_name_and_frills (files + filesno);
          size_t max_name_length = line_fmt->col_arr[col++];
          print_file_name_and_frills (files + filesno);

          filesno += rows;
          if (filesno >= files_index)
            break;

          indent (pos + name_length, pos + max_name_length);
          pos += max_name_length;
        }
      putchar ('\n');
    }
}

static void
print_horizontal (void)
{
  size_t filesno;
  size_t pos = 0;
  size_t cols = calculate_columns (false);
  struct column_info const *line_fmt = &column_info[cols - 1];
  size_t name_length = length_of_file_name_and_frills (files);
  size_t max_name_length = line_fmt->col_arr[0];

  /* Print first entry.  */
  print_file_name_and_frills (files);

  /* Now the rest.  */
  for (filesno = 1; filesno < files_index; ++filesno)
    {
      size_t col = filesno % cols;

      if (col == 0)
        {
          putchar ('\n');
          pos = 0;
        }
      else
        {
          indent (pos + name_length, pos + max_name_length);
          pos += max_name_length;
        }

      print_file_name_and_frills (files + filesno);

      name_length = length_of_file_name_and_frills (files + filesno);
      max_name_length = line_fmt->col_arr[col];
    }
  putchar ('\n');
}

static void
print_with_commas (void)
{
  size_t filesno;
  size_t pos = 0;

  for (filesno = 0; filesno < files_index; filesno++)
    {
      size_t len = length_of_file_name_and_frills (files + filesno);

      if (filesno != 0)
        {
          char separator;

          if (pos + len + 2 < line_length)
            {
              pos += 2;
              separator = ' ';
            }
          else
            {
              pos = 0;
              separator = '\n';
            }

          putchar (',');
          putchar (separator);
        }

      print_file_name_and_frills (files + filesno);
      pos += len;
    }
  putchar ('\n');
}

/* Assuming cursor is at position FROM, indent up to position TO.
   Use a TAB character instead of two or more spaces whenever possible.  */

static void
indent (size_t from, size_t to)
{
  while (from < to)
    {
      if (tabsize != 0 && to / tabsize > (from + 1) / tabsize)
        {
          putchar ('\t');
          from += tabsize - from % tabsize;
        }
      else
        {
          putchar (' ');
          from++;
        }
    }
}

/* Put DIRNAME/NAME into DEST, handling `.' and `/' properly. */
/* FIXME: maybe remove this function someday.  See about using a
   non-malloc'ing version of path_concat.  */

static void
attach (char *dest, const char *dirname, const char *name)
{
  const char *dirnamep = dirname;

  /* Copy dirname if it is not ".". */
  if (dirname[0] != '.' || dirname[1] != 0)
    {
      while (*dirnamep)
        *dest++ = *dirnamep++;
      /* Add '/' if `dirname' doesn't already end with it. */
      if (dirnamep > dirname && dirnamep[-1] != '/')
        *dest++ = '/';
    }
  while (*name)
    *dest++ = *name++;
  *dest = 0;
}

/* Allocate enough column info suitable for the current number of
   files and display columns, and initialize the info to represent the
   narrowest possible columns.  */

static void
init_column_info (void)
{
  size_t i;
  size_t max_cols = MIN (max_idx, files_index);

  /* Currently allocated columns in column_info.  */
  static size_t column_info_alloc;

  if (column_info_alloc < max_cols)
    {
      size_t new_column_info_alloc;
      size_t *p;

      if (max_cols < max_idx / 2)
        {
          /* The number of columns is far less than the display width
             allows.  Grow the allocation, but only so that it's
             double the current requirements.  If the display is
             extremely wide, this avoids allocating a lot of memory
             that is never needed.  */
          column_info = xnrealloc (column_info, max_cols,
                                   2 * sizeof *column_info);
          new_column_info_alloc = 2 * max_cols;
        }
      else
        {
          column_info = xnrealloc (column_info, max_idx, sizeof *column_info);
          new_column_info_alloc = max_idx;
        }

      /* Allocate the new size_t objects by computing the triangle
         formula n * (n + 1) / 2, except that we don't need to
         allocate the part of the triangle that we've already
         allocated.  Check for address arithmetic overflow.  */
      {
        size_t column_info_growth = new_column_info_alloc - column_info_alloc;
        size_t s = column_info_alloc + 1 + new_column_info_alloc;
        size_t t = s * column_info_growth;
        if (s < new_column_info_alloc || t / column_info_growth != s)
          xalloc_die ();
        p = xnmalloc (t / 2, sizeof *p);
      }

      /* Grow the triangle by parceling out the cells just allocated.  */
      for (i = column_info_alloc; i < new_column_info_alloc; i++)
        {
          column_info[i].col_arr = p;
          p += i + 1;
        }

      column_info_alloc = new_column_info_alloc;
    }

  for (i = 0; i < max_cols; ++i)
    {
      size_t j;

      column_info[i].valid_len = true;
      column_info[i].line_len = (i + 1) * MIN_COLUMN_WIDTH;
      for (j = 0; j <= i; ++j)
        column_info[i].col_arr[j] = MIN_COLUMN_WIDTH;
    }
}

/* Calculate the number of columns needed to represent the current set
   of files in the current display width.  */

static size_t
calculate_columns (bool by_columns)
{
  size_t filesno;               /* Index into files. */
  size_t cols;                  /* Number of files across. */

  /* Normally the maximum number of columns is determined by the
     screen width.  But if few files are available this might limit it
     as well.  */
  size_t max_cols = MIN (max_idx, files_index);

  init_column_info ();

  /* Compute the maximum number of possible columns.  */
  for (filesno = 0; filesno < files_index; ++filesno)
    {
      size_t name_length = length_of_file_name_and_frills (files + filesno);
      size_t i;

      for (i = 0; i < max_cols; ++i)
        {
          if (column_info[i].valid_len)
            {
              size_t idx = (by_columns
                            ? filesno / ((files_index + i) / (i + 1))
                            : filesno % (i + 1));
              size_t real_length = name_length + (idx == i ? 0 : 2);

              if (column_info[i].col_arr[idx] < real_length)
                {
                  column_info[i].line_len += (real_length
                                              - column_info[i].col_arr[idx]);
                  column_info[i].col_arr[idx] = real_length;
                  column_info[i].valid_len = (column_info[i].line_len
                                              < line_length);
                }
            }
        }
    }

  /* Find maximum allowed columns.  */
  for (cols = max_cols; 1 < cols; --cols)
    {
      if (column_info[cols - 1].valid_len)
        break;
    }

  return cols;
}

void
usage (int status)
{
  if (status != 0)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
             program_name);
  else
    {
      printf (_("Usage: %s [OPTION]... [FILE]...\n"), program_name);
      fputs (_("\
List information about the FILEs (the current directory by default).\n\
Sort entries alphabetically if none of -cftuSUX nor --sort.\n\
\n\
"), stdout);
      fputs (_("\
Mandatory arguments to long options are mandatory for short options too.\n\
"), stdout);
      fputs (_("\
  -a, --all                  do not hide entries starting with .\n\
  -A, --almost-all           do not list implied . and ..\n\
      --author               print the author of each file\n\
  -b, --escape               print octal escapes for nongraphic characters\n\
"), stdout);
      fputs (_("\
      --block-size=SIZE      use SIZE-byte blocks\n\
  -B, --ignore-backups       do not list implied entries ending with ~\n\
  -c                         with -lt: sort by, and show, ctime (time of last\n\
                               modification of file status information)\n\
                               with -l: show ctime and sort by name\n\
                               otherwise: sort by ctime\n\
"), stdout);
      fputs (_("\
  -C                         list entries by columns\n\
      --color[=WHEN]         control whether color is used to distinguish file\n\
                               types.  WHEN may be `never', `always', or `auto'\n\
  -d, --directory            list directory entries instead of contents,\n\
                               and do not dereference symbolic links\n\
  -D, --dired                generate output designed for Emacs' dired mode\n\
"), stdout);
      fputs (_("\
  -f                         do not sort, enable -aU, disable -lst\n\
  -F, --classify             append indicator (one of */=@|) to entries\n\
      --format=WORD          across -x, commas -m, horizontal -x, long -l,\n\
                               single-column -1, verbose -l, vertical -C\n\
      --full-time            like -l --time-style=full-iso\n\
"), stdout);
      fputs (_("\
  -g                         like -l, but do not list owner\n\
  -G, --no-group             inhibit display of group information\n\
  -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)\n\
      --si                   likewise, but use powers of 1000 not 1024\n\
  -H, --dereference-command-line\n\
                             follow symbolic links listed on the command line\n\
      --dereference-command-line-symlink-to-dir\n\
                             follow each command line symbolic link\n\
                               that points to a directory\n\
"), stdout);
      fputs (_("\
      --indicator-style=WORD append indicator with style WORD to entry names:\n\
                               none (default), classify (-F), file-type (-p)\n\
  -i, --inode                print index number of each file\n\
  -I, --ignore=PATTERN       do not list implied entries matching shell PATTERN\n\
  -k                         like --block-size=1K\n\
"), stdout);
      fputs (_("\
  -l                         use a long listing format\n\
  -L, --dereference          when showing file information for a symbolic\n\
                               link, show information for the file the link\n\
                               references rather than for the link itself\n\
  -m                         fill width with a comma separated list of entries\n\
"), stdout);
      fputs (_("\
  -n, --numeric-uid-gid      like -l, but list numeric UIDs and GIDs\n\
  -N, --literal              print raw entry names (don't treat e.g. control\n\
                               characters specially)\n\
  -o                         like -l, but do not list group information\n\
  -p, --file-type            append indicator (one of /=@|) to entries\n\
"), stdout);
      fputs (_("\
  -q, --hide-control-chars   print ? instead of non graphic characters\n\
      --show-control-chars   show non graphic characters as-is (default\n\
                             unless program is `ls' and output is a terminal)\n\
  -Q, --quote-name           enclose entry names in double quotes\n\
      --quoting-style=WORD   use quoting style WORD for entry names:\n\
                               literal, locale, shell, shell-always, c, escape\n\
"), stdout);
      fputs (_("\
  -r, --reverse              reverse order while sorting\n\
  -R, --recursive            list subdirectories recursively\n\
  -s, --size                 print size of each file, in blocks\n\
"), stdout);
      fputs (_("\
  -S                         sort by file size\n\
      --sort=WORD            extension -X, none -U, size -S, time -t,\n\
                               version -v\n\
                             status -c, time -t, atime -u, access -u, use -u\n\
      --time=WORD            show time as WORD instead of modification time:\n\
                               atime, access, use, ctime or status; use\n\
                               specified time as sort key if --sort=time\n\
"), stdout);
      fputs (_("\
      --time-style=STYLE     show times using style STYLE:\n\
                               full-iso, long-iso, iso, locale, +FORMAT\n\
                             FORMAT is interpreted like `date'; if FORMAT is\n\
                             FORMAT1<newline>FORMAT2, FORMAT1 applies to\n\
                             non-recent files and FORMAT2 to recent files;\n\
                             if STYLE is prefixed with `posix-', STYLE\n\
                             takes effect only outside the POSIX locale\n\
  -t                         sort by modification time\n\
  -T, --tabsize=COLS         assume tab stops at each COLS instead of 8\n\
"), stdout);
      fputs (_("\
  -u                         with -lt: sort by, and show, access time\n\
                               with -l: show access time and sort by name\n\
                               otherwise: sort by access time\n\
  -U                         do not sort; list entries in directory order\n\
  -v                         sort by version\n\
"), stdout);
      fputs (_("\
  -w, --width=COLS           assume screen width instead of current value\n\
  -x                         list entries by lines instead of by columns\n\
  -X                         sort alphabetically by entry extension\n\
  -1                         list one file per line\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\n\
SIZE may be (or may be an integer optionally followed by) one of following:\n\
kB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.\n\
"), stdout);
      fputs (_("\
\n\
By default, color is not used to distinguish types of files.  That is\n\
equivalent to using --color=none.  Using the --color option without the\n\
optional WHEN argument is equivalent to using --color=always.  With\n\
--color=auto, color codes are output only if standard output is connected\n\
to a terminal (tty).\n\
"), stdout);
      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    }
  exit (status);
}