/*
 * Trivial ls for comparing two directories after running an rsync.
 *
 * Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
 * Copyright (C) 2003-2007 Wayne Davison
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.,
 * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
 */

/* The problem with using the system's own ls is that some features
 * have little quirks that make directories look different when for
 * our purposes they're the same -- for example, the BSD braindamage
 * about setting the mode on symlinks based on your current umask.
 *
 * All the filenames must be given on the command line -- tls does not
 * even read directories, let alone recurse.  The typical usage is
 * "find|sort|xargs tls".
 *
 * The format is not exactly the same as any particular Unix ls(1).
 *
 * A key requirement for this program is that the output be "very
 * reproducible."  So we mask away information that can accidentally
 * change. */

#include "rsync.h"
#include "lib/sysxattrs.h"

#define PROGRAM "tls"

/* These are to make syscall.o shut up. */
int dry_run = 0;
int am_root = 0;
int read_only = 1;
int list_only = 0;
int preserve_perms = 0;

#ifdef HAVE_LINUX_XATTRS
#define XSTAT_ATTR "user.rsync.%stat"
#else
#define XSTAT_ATTR "rsync.%stat"
#endif

static int stat_xattr(const char *fname, STRUCT_STAT *fst)
{
	int mode, rdev_major, rdev_minor, uid, gid, len;
	char buf[256];

	if (am_root >= 0 || IS_DEVICE(fst->st_mode) || IS_SPECIAL(fst->st_mode))
		return -1;

	len = sys_lgetxattr(fname, XSTAT_ATTR, buf, sizeof buf - 1);
	if (len >= (int)sizeof buf) {
		len = -1;
		errno = ERANGE;
	}
	if (len < 0) {
		if (errno == ENOTSUP || errno == ENOATTR)
			return -1;
		if (errno == EPERM && S_ISLNK(fst->st_mode)) {
			fst->st_uid = 0;
			fst->st_gid = 0;
			return 0;
		}
		fprintf(stderr, "failed to read xattr %s for %s: %s\n",
			XSTAT_ATTR, fname, strerror(errno));
		return -1;
	}
	buf[len] = '\0';

	if (sscanf(buf, "%o %d,%d %d:%d",
		   &mode, &rdev_major, &rdev_minor, &uid, &gid) != 5) {
		fprintf(stderr, "Corrupt %s xattr attached to %s: \"%s\"\n",
			XSTAT_ATTR, fname, buf);
		exit(1);
	}

	fst->st_mode = from_wire_mode(mode);
	fst->st_rdev = MAKEDEV(rdev_major, rdev_minor);
	fst->st_uid = uid;
	fst->st_gid = gid;

	return 0;
}

static void failed(char const *what, char const *where)
{
	fprintf(stderr, PROGRAM ": %s %s: %s\n",
		what, where, strerror(errno));
	exit(1);
}

static void list_file(const char *fname)
{
	STRUCT_STAT buf;
	char permbuf[PERMSTRING_SIZE];
	struct tm *mt;
	char datebuf[50];
	char linkbuf[4096];

	if (do_lstat(fname, &buf) < 0)
		failed("stat", fname);
	if (am_root < 0)
		stat_xattr(fname, &buf);

	/* The size of anything but a regular file is probably not
	 * worth thinking about. */
	if (!S_ISREG(buf.st_mode))
		buf.st_size = 0;

	/* On some BSD platforms the mode bits of a symlink are
	 * undefined.  Also it tends not to be possible to reset a
	 * symlink's mtime, so we have to ignore it too. */
	if (S_ISLNK(buf.st_mode)) {
		int len;
		buf.st_mode &= ~0777;
		buf.st_mtime = (time_t)0;
		buf.st_uid = buf.st_gid = 0;
		strlcpy(linkbuf, " -> ", sizeof linkbuf);
		/* const-cast required for silly UNICOS headers */
		len = readlink((char *) fname, linkbuf+4, sizeof(linkbuf) - 4);
		if (len == -1)
			failed("readlink", fname);
		else
			/* it's not nul-terminated */
			linkbuf[4+len] = 0;
	} else {
		linkbuf[0] = 0;
	}

	permstring(permbuf, buf.st_mode);

	if (buf.st_mtime) {
		mt = gmtime(&buf.st_mtime);

		snprintf(datebuf, sizeof datebuf,
			"%04d-%02d-%02d %02d:%02d:%02d",
			(int)mt->tm_year + 1900,
			(int)mt->tm_mon + 1,
			(int)mt->tm_mday,
			(int)mt->tm_hour,
			(int)mt->tm_min,
			(int)mt->tm_sec);
	} else
		strlcpy(datebuf, "                   ", sizeof datebuf);

	/* TODO: Perhaps escape special characters in fname? */

	printf("%s ", permbuf);
	if (S_ISCHR(buf.st_mode) || S_ISBLK(buf.st_mode)) {
		printf("%5ld,%6ld",
		    (long)major(buf.st_rdev),
		    (long)minor(buf.st_rdev));
	} else /* NB: use double for size since it might not fit in a long. */
		printf("%12.0f", (double)buf.st_size);
	printf(" %6ld.%-6ld %6ld %s %s%s\n",
	       (long)buf.st_uid, (long)buf.st_gid, (long)buf.st_nlink,
	       datebuf, fname, linkbuf);
}

int
main(int argc, char *argv[])
{
	if (argc < 2) {
		fprintf(stderr, "usage: " PROGRAM " FILE ...\n"
			"Trivial file listing program for portably checking rsync\n");
		return 1;
	}

	if (getenv("RSYNC_FAKE_SUPER"))
		am_root = -1;

	for (argv++; *argv; argv++)
		list_file(*argv);

	return 0;
}