Add 'corebinutils/ls/' from commit '06b170dd48138a26fdfe1b822ba9846a26a2fa0f'

git-subtree-dir: corebinutils/ls
git-subtree-mainline: ec6a123cffbe492c576ec1ad545d5296321a86e1
git-subtree-split: 06b170dd48138a26fdfe1b822ba9846a26a2fa0f

1 files changed, 776 insertions, 0 deletions

diff --git a/corebinutils/ls/ls.c b/corebinutils/ls/ls.c
new file mode 100644
index 0000000000..547d2bcfee
--- /dev/null
+++ b/corebinutils/ls/ls.c
@@ -0,0 +1,776 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1989, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Copyright (c) 2026
+ *  Project Tick. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Michael Fischbein.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+
+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include <err.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <locale.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+
+#include "ls.h"
+#include "extern.h"
+
+#ifndef AT_FDCWD
+#define AT_FDCWD (-100)
+#endif
+
+#ifndef AT_SYMLINK_NOFOLLOW
+#define AT_SYMLINK_NOFOLLOW 0x100
+#endif
+
+#ifndef STATX_TYPE
+struct statx_timestamp {
+	int64_t tv_sec;
+	uint32_t tv_nsec;
+	int32_t __reserved;
+};
+
+struct statx {
+	uint32_t stx_mask;
+	uint32_t stx_blksize;
+	uint64_t stx_attributes;
+	uint32_t stx_nlink;
+	uint32_t stx_uid;
+	uint32_t stx_gid;
+	uint16_t stx_mode;
+	uint16_t __spare0[1];
+	uint64_t stx_ino;
+	uint64_t stx_size;
+	uint64_t stx_blocks;
+	uint64_t stx_attributes_mask;
+	struct statx_timestamp stx_atime;
+	struct statx_timestamp stx_btime;
+	struct statx_timestamp stx_ctime;
+	struct statx_timestamp stx_mtime;
+	uint32_t stx_rdev_major;
+	uint32_t stx_rdev_minor;
+	uint32_t stx_dev_major;
+	uint32_t stx_dev_minor;
+	uint64_t stx_mnt_id;
+	uint32_t stx_dio_mem_align;
+	uint32_t stx_dio_offset_align;
+	uint64_t __spare3[12];
+};
+
+#define STATX_TYPE 0x00000001U
+#define STATX_MODE 0x00000002U
+#define STATX_NLINK 0x00000004U
+#define STATX_UID 0x00000008U
+#define STATX_GID 0x00000010U
+#define STATX_ATIME 0x00000020U
+#define STATX_MTIME 0x00000040U
+#define STATX_CTIME 0x00000080U
+#define STATX_INO 0x00000100U
+#define STATX_SIZE 0x00000200U
+#define STATX_BLOCKS 0x00000400U
+#define STATX_BASIC_STATS 0x000007ffU
+#define STATX_BTIME 0x00000800U
+#endif
+
+static void init_options(struct context *ctx);
+static int parse_options(struct context *ctx, int argc, char **argv);
+static void parse_long_option(struct context *ctx, const char *arg);
+static void require_option_argument(int argc, char **argv, int *index,
+    const char *opt_name, const char **value);
+static void finalize_options(struct context *ctx);
+static size_t parse_size_t_or_default(const char *text, size_t fallback);
+static bool follow_root_argument(const struct context *ctx);
+static bool follow_child_entry(const struct context *ctx);
+static int collect_path_entry(struct context *ctx, struct entry *entry,
+    const char *path, const char *name, bool root_argument);
+static int stat_with_policy(const struct context *ctx, const char *path,
+    bool root_argument, struct entry *entry);
+static int fill_birthtime(const char *path, bool follow, struct entry *entry);
+static void add_dot_entries(struct context *ctx, struct entry_list *list,
+    const char *dir_path);
+static bool collect_directory_entries(struct context *ctx,
+    struct entry_list *list, const char *dir_path);
+static void list_root_files(struct context *ctx, struct entry_list *roots);
+static void list_directory(struct context *ctx, const struct entry *dir,
+    const char *title, bool print_header, const struct visit_stack *stack,
+    int operand_count);
+static bool should_recurse(const struct context *ctx, const struct entry *entry);
+static bool visit_stack_contains(const struct visit_stack *stack,
+    const struct entry *entry);
+static void print_directory_header(struct context *ctx, const char *title,
+    bool print_header);
+static void unsupported_option(const char *opt, const char *reason);
+static void warn_path_error(struct context *ctx, const char *path, int error);
+static int linux_statx(const char *path, int flags, struct statx *stx);
+
+static void
+init_options(struct context *ctx)
+{
+	memset(ctx, 0, sizeof(*ctx));
+	ctx->now = time(NULL);
+	ctx->opt.layout = isatty(STDOUT_FILENO) ? LAYOUT_COLUMNS : LAYOUT_SINGLE;
+	ctx->opt.sort = SORT_NAME;
+	ctx->opt.time_field = TIME_MTIME;
+	ctx->opt.follow = FOLLOW_DEFAULT;
+	ctx->opt.group_dirs = GROUP_NONE;
+	ctx->opt.name_mode = isatty(STDOUT_FILENO) ? NAME_PRINTABLE : NAME_LITERAL;
+	ctx->opt.color_mode = COLOR_DEFAULT;
+	ctx->opt.block_units = 1;
+	ctx->opt.stdout_is_tty = isatty(STDOUT_FILENO);
+	ctx->opt.terminal_width = 80;
+}
+
+static size_t
+parse_size_t_or_default(const char *text, size_t fallback)
+{
+	size_t value;
+	unsigned char ch;
+
+	if (text == NULL || *text == '\0')
+		return (fallback);
+	value = 0;
+	while (*text != '\0') {
+		ch = (unsigned char)*text++;
+		if (!isdigit(ch))
+			return (fallback);
+		if (value > (SIZE_MAX - (size_t)(ch - '0')) / 10)
+			return (fallback);
+		value = value * 10 + (size_t)(ch - '0');
+	}
+	if (value == 0)
+		return (fallback);
+	return (value);
+}
+
+static void
+require_option_argument(int argc, char **argv, int *index, const char *opt_name,
+    const char **value)
+{
+	if (++(*index) >= argc)
+		errx(2, "option %s requires an argument", opt_name);
+	*value = argv[*index];
+}
+
+static void
+unsupported_option(const char *opt, const char *reason)
+{
+	errx(2, "option %s is not supported on Linux: %s", opt, reason);
+}
+
+static void
+parse_long_option(struct context *ctx, const char *arg)
+{
+	const char *value;
+
+	value = strchr(arg, '=');
+	if (value != NULL)
+		value++;
+	if (strncmp(arg, "--color", 7) == 0 &&
+	    (arg[7] == '\0' || arg[7] == '=')) {
+		if (value == NULL || strcmp(value, "always") == 0 ||
+		    strcmp(value, "yes") == 0 || strcmp(value, "force") == 0)
+			ctx->opt.color_mode = COLOR_ALWAYS;
+		else if (strcmp(value, "auto") == 0 || strcmp(value, "tty") == 0 ||
+		    strcmp(value, "if-tty") == 0)
+			ctx->opt.color_mode = COLOR_AUTO;
+		else if (strcmp(value, "never") == 0 || strcmp(value, "no") == 0 ||
+		    strcmp(value, "none") == 0)
+			ctx->opt.color_mode = COLOR_NEVER;
+		else
+			errx(2, "unsupported --color value '%s' (must be always, auto, or never)",
+			    value);
+		return;
+	}
+	if (strncmp(arg, "--group-directories", 19) == 0 &&
+	    (arg[19] == '\0' || arg[19] == '=')) {
+		if (value == NULL || strcmp(value, "first") == 0)
+			ctx->opt.group_dirs = GROUP_DIRS_FIRST;
+		else if (strcmp(value, "last") == 0)
+			ctx->opt.group_dirs = GROUP_DIRS_LAST;
+		else
+			errx(2, "unsupported --group-directories value '%s' (must be first or last)",
+			    value);
+		return;
+	}
+	if (strcmp(arg, "--group-directories-first") == 0) {
+		ctx->opt.group_dirs = GROUP_DIRS_FIRST;
+		return;
+	}
+	usage();
+}
+
+static int
+parse_options(struct context *ctx, int argc, char **argv)
+{
+	int i;
+	int j;
+	const char *value;
+
+	for (i = 1; i < argc; i++) {
+		if (argv[i][0] != '-' || strcmp(argv[i], "-") == 0)
+			break;
+		if (strcmp(argv[i], "--") == 0) {
+			i++;
+			break;
+		}
+		if (strncmp(argv[i], "--", 2) == 0) {
+			parse_long_option(ctx, argv[i]);
+			continue;
+		}
+		for (j = 1; argv[i][j] != '\0'; j++) {
+			switch (argv[i][j]) {
+			case '1':
+				ctx->opt.layout = LAYOUT_SINGLE;
+				break;
+			case 'A':
+				ctx->opt.show_almost_all = true;
+				break;
+			case 'B':
+				ctx->opt.name_mode = NAME_OCTAL;
+				break;
+			case 'C':
+				ctx->opt.layout = LAYOUT_COLUMNS;
+				ctx->opt.sort_across = false;
+				break;
+			case 'D':
+				if (argv[i][j + 1] != '\0') {
+					ctx->opt.time_format = &argv[i][j + 1];
+					j = (int)strlen(argv[i]) - 1;
+				} else {
+					require_option_argument(argc, argv, &i, "-D", &value);
+					ctx->opt.time_format = value;
+					goto next_option_argument;
+				}
+				break;
+			case 'F':
+				ctx->opt.show_type = true;
+				ctx->opt.slash_only = false;
+				break;
+			case 'G':
+				ctx->opt.color_mode = COLOR_AUTO;
+				break;
+			case 'H':
+				ctx->opt.follow = FOLLOW_COMMAND_LINE;
+				break;
+			case 'I':
+				ctx->opt.disable_root_almost_all = true;
+				break;
+			case 'L':
+				ctx->opt.follow = FOLLOW_ALL;
+				break;
+			case 'P':
+				ctx->opt.follow = FOLLOW_NEVER;
+				break;
+			case 'R':
+				ctx->opt.recursive = true;
+				break;
+			case 'S':
+				ctx->opt.sort = SORT_SIZE;
+				break;
+			case 'T':
+				ctx->opt.show_full_time = true;
+				break;
+			case 'U':
+				ctx->opt.time_field = TIME_BTIME;
+				break;
+			case 'W':
+				unsupported_option("-W", "Linux VFS has no FreeBSD whiteout entries");
+				break;
+			case 'Z':
+				unsupported_option("-Z", "FreeBSD MAC labels do not map to a portable Linux userland interface");
+				break;
+			case 'a':
+				ctx->opt.show_all = true;
+				ctx->opt.show_almost_all = false;
+				break;
+			case 'b':
+				ctx->opt.name_mode = NAME_ESCAPE;
+				break;
+			case 'c':
+				ctx->opt.time_field = TIME_CTIME;
+				break;
+			case 'd':
+				ctx->opt.list_directory_itself = true;
+				ctx->opt.recursive = false;
+				break;
+			case 'f':
+				ctx->opt.no_sort = true;
+				ctx->opt.show_all = true;
+				ctx->opt.show_almost_all = false;
+				break;
+			case 'g':
+				ctx->opt.layout = LAYOUT_LONG;
+				ctx->opt.suppress_owner = true;
+				break;
+			case 'h':
+				ctx->opt.human_readable = true;
+				ctx->opt.block_units = 1;
+				break;
+			case 'i':
+				ctx->opt.show_inode = true;
+				break;
+			case 'k':
+				ctx->opt.human_readable = false;
+				ctx->opt.block_units = 2;
+				break;
+			case 'l':
+				ctx->opt.layout = LAYOUT_LONG;
+				break;
+			case 'm':
+				ctx->opt.layout = LAYOUT_STREAM;
+				break;
+			case 'n':
+				ctx->opt.numeric_ids = true;
+				ctx->opt.layout = LAYOUT_LONG;
+				break;
+			case 'o':
+				unsupported_option("-o", "FreeBSD file flags require a filesystem-specific ioctl surface on Linux; use lsattr for ext-family flags");
+				break;
+			case 'p':
+				ctx->opt.show_type = true;
+				ctx->opt.slash_only = true;
+				break;
+			case 'q':
+				ctx->opt.name_mode = NAME_PRINTABLE;
+				break;
+			case 'r':
+				ctx->opt.reverse_sort = true;
+				break;
+			case 's':
+				ctx->opt.show_blocks = true;
+				break;
+			case 't':
+				ctx->opt.sort = SORT_TIME;
+				break;
+			case 'u':
+				ctx->opt.time_field = TIME_ATIME;
+				break;
+			case 'v':
+				ctx->opt.sort = SORT_VERSION;
+				break;
+			case 'w':
+				ctx->opt.name_mode = NAME_LITERAL;
+				break;
+			case 'x':
+				ctx->opt.layout = LAYOUT_COLUMNS;
+				ctx->opt.sort_across = true;
+				break;
+			case 'y':
+				ctx->opt.same_sort_direction = true;
+				break;
+			case ',':
+				ctx->opt.thousands = true;
+				break;
+			default:
+				usage();
+			}
+		}
+next_option_argument:
+		;
+	}
+	return (i);
+}
+
+static void
+finalize_options(struct context *ctx)
+{
+	const char *columns;
+	const char *clicolor_force;
+	const char *clicolor;
+	const char *colorterm;
+	const char *same_sort;
+	struct winsize win;
+	bool env_color;
+	bool force_color;
+
+	columns = getenv("COLUMNS");
+	ctx->opt.terminal_width = parse_size_t_or_default(columns, 80);
+	if (columns == NULL && ctx->opt.stdout_is_tty &&
+	    ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 && win.ws_col > 0)
+		ctx->opt.terminal_width = win.ws_col;
+	same_sort = getenv("LS_SAMESORT");
+	if (same_sort != NULL && *same_sort != '\0')
+		ctx->opt.same_sort_direction = true;
+	if (!ctx->opt.show_all && geteuid() == 0 && !ctx->opt.disable_root_almost_all)
+		ctx->opt.show_almost_all = true;
+	clicolor = getenv("CLICOLOR");
+	colorterm = getenv("COLORTERM");
+	clicolor_force = getenv("CLICOLOR_FORCE");
+	env_color = (clicolor != NULL) || (colorterm != NULL && *colorterm != '\0');
+	force_color = clicolor_force != NULL && *clicolor_force != '\0';
+	switch (ctx->opt.color_mode) {
+	case COLOR_NEVER:
+		ctx->opt.colorize = false;
+		break;
+	case COLOR_ALWAYS:
+		ctx->opt.colorize = true;
+		break;
+	case COLOR_AUTO:
+		ctx->opt.colorize = ctx->opt.stdout_is_tty || force_color;
+		break;
+	case COLOR_DEFAULT:
+	default:
+		ctx->opt.colorize = env_color && (ctx->opt.stdout_is_tty || force_color);
+		break;
+	}
+}
+
+static bool
+follow_root_argument(const struct context *ctx)
+{
+	switch (ctx->opt.follow) {
+	case FOLLOW_COMMAND_LINE:
+		return (true);
+	case FOLLOW_ALL:
+		return (true);
+	case FOLLOW_NEVER:
+		return (false);
+	case FOLLOW_DEFAULT:
+	default:
+		return (!ctx->opt.list_directory_itself && ctx->opt.layout != LAYOUT_LONG &&
+		    (!ctx->opt.show_type || ctx->opt.slash_only));
+	}
+}
+
+static bool
+follow_child_entry(const struct context *ctx)
+{
+	return (ctx->opt.follow == FOLLOW_ALL);
+}
+
+static int
+linux_statx(const char *path, int flags, struct statx *stx)
+{
+#ifdef SYS_statx
+	return ((int)syscall(SYS_statx, AT_FDCWD, path, flags,
+	    STATX_BASIC_STATS | STATX_BTIME, stx));
+#else
+	(void)path;
+	(void)flags;
+	(void)stx;
+	errno = ENOSYS;
+	return (-1);
+#endif
+}
+
+static int
+fill_birthtime(const char *path, bool follow, struct entry *entry)
+{
+	struct statx stx;
+	int flags;
+
+	memset(&stx, 0, sizeof(stx));
+	flags = follow ? 0 : AT_SYMLINK_NOFOLLOW;
+	if (linux_statx(path, flags, &stx) != 0)
+		return (-1);
+	if ((stx.stx_mask & STATX_BTIME) == 0)
+		return (-1);
+	entry->btime.ts.tv_sec = stx.stx_btime.tv_sec;
+	entry->btime.ts.tv_nsec = stx.stx_btime.tv_nsec;
+	entry->btime.available = true;
+	return (0);
+}
+
+static int
+stat_with_policy(const struct context *ctx, const char *path, bool root_argument,
+    struct entry *entry)
+{
+	bool follow;
+	int error;
+
+	follow = root_argument ? follow_root_argument(ctx) : follow_child_entry(ctx);
+	entry->followed = follow;
+	if ((follow ? stat(path, &entry->st) : lstat(path, &entry->st)) != 0) {
+		entry->stat_errno = errno;
+		entry->stat_ok = false;
+		return (-1);
+	}
+	entry->stat_ok = true;
+	entry->is_dir = S_ISDIR(entry->st.st_mode);
+	entry->is_symlink = S_ISLNK(entry->st.st_mode);
+	if (ctx->opt.time_field == TIME_BTIME) {
+		error = fill_birthtime(path, follow, entry);
+		if (error != 0)
+			entry->btime.available = false;
+	}
+	return (0);
+}
+
+static int
+collect_path_entry(struct context *ctx, struct entry *entry, const char *path,
+    const char *name, bool root_argument)
+{
+	memset(entry, 0, sizeof(*entry));
+	entry->name = xstrdup(name);
+	entry->path = xstrdup(path);
+	if (stat_with_policy(ctx, path, root_argument, entry) != 0) {
+		if (entry->stat_errno == 0)
+			entry->stat_errno = errno;
+		return (-1);
+	}
+	return (0);
+}
+
+static void
+warn_path_error(struct context *ctx, const char *path, int error)
+{
+	warnx("%s: %s", path, strerror(error));
+	ctx->exit_status = 1;
+}
+
+static void
+add_dot_entries(struct context *ctx, struct entry_list *list, const char *dir_path)
+{
+	struct entry entry;
+	char *path;
+
+	path = join_path(dir_path, ".");
+	if (collect_path_entry(ctx, &entry, path, ".", false) == 0)
+		append_entry(list, &entry);
+	else {
+		warn_path_error(ctx, path, entry.stat_errno);
+		free_entry(&entry);
+	}
+	free(path);
+	path = join_path(dir_path, "..");
+	if (collect_path_entry(ctx, &entry, path, "..", false) == 0)
+		append_entry(list, &entry);
+	else {
+		warn_path_error(ctx, path, entry.stat_errno);
+		free_entry(&entry);
+	}
+	free(path);
+}
+
+static bool
+collect_directory_entries(struct context *ctx, struct entry_list *list,
+    const char *dir_path)
+{
+	DIR *dirp;
+	struct dirent *dent;
+	struct entry entry;
+	char *path;
+
+	dirp = opendir(dir_path);
+	if (dirp == NULL) {
+		warn_path_error(ctx, dir_path, errno);
+		return (false);
+	}
+	if (ctx->opt.show_all)
+		add_dot_entries(ctx, list, dir_path);
+	while ((dent = readdir(dirp)) != NULL) {
+		if (strcmp(dent->d_name, ".") == 0 || strcmp(dent->d_name, "..") == 0)
+			continue;
+		if (!ctx->opt.show_all && !ctx->opt.show_almost_all &&
+		    dent->d_name[0] == '.')
+			continue;
+		path = join_path(dir_path, dent->d_name);
+		if (collect_path_entry(ctx, &entry, path, dent->d_name, false) == 0)
+			append_entry(list, &entry);
+		else {
+			warn_path_error(ctx, path, entry.stat_errno);
+			free_entry(&entry);
+		}
+		free(path);
+	}
+	closedir(dirp);
+	return (true);
+}
+
+static void
+print_directory_header(struct context *ctx, const char *title, bool print_header)
+{
+	if (!print_header)
+		return;
+	if (ctx->wrote_output)
+		putchar('\n');
+	print_name(&ctx->opt, title);
+	puts(":");
+}
+
+static bool
+visit_stack_contains(const struct visit_stack *stack, const struct entry *entry)
+{
+	while (stack != NULL) {
+		if (stack->dev == entry->st.st_dev && stack->ino == entry->st.st_ino)
+			return (true);
+		stack = stack->parent;
+	}
+	return (false);
+}
+
+static bool
+should_recurse(const struct context *ctx, const struct entry *entry)
+{
+	(void)ctx;
+	if (!entry->is_dir)
+		return (false);
+	if (strcmp(entry->name, ".") == 0 || strcmp(entry->name, "..") == 0)
+		return (false);
+	return (true);
+}
+
+static void
+list_directory(struct context *ctx, const struct entry *dir, const char *title,
+    bool print_header, const struct visit_stack *stack, int operand_count)
+{
+	struct entry_list list;
+	struct visit_stack here;
+	size_t i;
+	char *child_title;
+	bool child_header;
+
+	(void)operand_count;
+	memset(&list, 0, sizeof(list));
+	if (!collect_directory_entries(ctx, &list, dir->path))
+		return;
+	sort_entries(ctx, &list, false);
+	print_directory_header(ctx, title, print_header);
+	print_entries(ctx, &list, true);
+	if (!ctx->opt.recursive) {
+		free_entry_list(&list);
+		return;
+	}
+	here.dev = dir->st.st_dev;
+	here.ino = dir->st.st_ino;
+	here.parent = stack;
+	for (i = 0; i < list.len; i++) {
+		if (!should_recurse(ctx, &list.items[i]))
+			continue;
+		if (visit_stack_contains(&here, &list.items[i])) {
+			warnx("%s: directory causes a cycle", list.items[i].path);
+			ctx->exit_status = 1;
+			continue;
+		}
+		child_title = join_path(title, list.items[i].name);
+		child_header = true;
+		list_directory(ctx, &list.items[i], child_title, child_header, &here,
+		    operand_count);
+		free(child_title);
+	}
+	free_entry_list(&list);
+}
+
+static void
+list_root_files(struct context *ctx, struct entry_list *roots)
+{
+	struct entry_list files;
+	size_t i;
+
+	memset(&files, 0, sizeof(files));
+	for (i = 0; i < roots->len; i++) {
+		if (!roots->items[i].is_dir || ctx->opt.list_directory_itself) {
+			if (files.len == files.cap) {
+				files.cap = files.cap == 0 ? 8 : files.cap * 2;
+				files.items = xreallocarray(files.items, files.cap,
+				    sizeof(*files.items));
+			}
+			files.items[files.len++] = roots->items[i];
+		}
+	}
+	if (files.len == 0) {
+		free(files.items);
+		return;
+	}
+	sort_entries(ctx, &files, true);
+	print_entries(ctx, &files, false);
+	free(files.items);
+}
+
+int
+main(int argc, char **argv)
+{
+	struct context ctx;
+	struct entry_list roots;
+	struct entry entry;
+	int argi;
+	int operand_count;
+	size_t i;
+	bool print_header;
+
+	setlocale(LC_ALL, "");
+	init_options(&ctx);
+	argi = parse_options(&ctx, argc, argv);
+	finalize_options(&ctx);
+	memset(&roots, 0, sizeof(roots));
+	operand_count = argc - argi;
+	if (operand_count == 0)
+		operand_count = 1;
+	if (argi == argc) {
+		if (collect_path_entry(&ctx, &entry, ".", ".", true) == 0)
+			append_entry(&roots, &entry);
+		else {
+			warn_path_error(&ctx, ".", entry.stat_errno);
+			free_entry(&entry);
+		}
+	} else {
+		for (; argi < argc; argi++) {
+			if (collect_path_entry(&ctx, &entry, argv[argi], argv[argi], true) == 0)
+				append_entry(&roots, &entry);
+			else {
+				warn_path_error(&ctx, argv[argi], entry.stat_errno);
+				free_entry(&entry);
+			}
+		}
+	}
+	sort_entries(&ctx, &roots, true);
+	list_root_files(&ctx, &roots);
+	for (i = 0; i < roots.len; i++) {
+		if (!roots.items[i].is_dir || ctx.opt.list_directory_itself)
+			continue;
+		print_header = operand_count > 1;
+		list_directory(&ctx, &roots.items[i], roots.items[i].name,
+		    print_header, NULL, operand_count);
+	}
+	free_entry_list(&roots);
+	return (ctx.exit_status);
+}
+
+void
+usage(void)
+{
+	fprintf(stderr,
+	    "usage: ls [-ABCFGHILPRSTUabcdfghiklmnopqrstuvwxy1,] [--color=when] "
+	    "[--group-directories=first|last] [-D format] [file ...]\n");
+	exit(1);
+}