initial population

2 files changed, 826 insertions, 0 deletions

diff --git a/bin/rm/rm.1 b/bin/rm/rm.1
new file mode 100644
index 0000000..d7c5720
--- /dev/null
+++ b/bin/rm/rm.1
@@ -0,0 +1,215 @@
+.\"	$NetBSD: rm.1,v 1.29 2017/07/03 21:33:23 wiz Exp $
+.\"
+.\" Copyright (c) 1990, 1993, 1994, 2003
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" the Institute of Electrical and Electronics Engineers, Inc.
+.\"
+.\" 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.
+.\"
+.\"	@(#)rm.1	8.5 (Berkeley) 12/5/94
+.\"
+.Dd August 12, 2016
+.Dt RM 1
+.Os
+.Sh NAME
+.Nm rm
+.Nd remove directory entries
+.Sh SYNOPSIS
+.Nm
+.Op Fl f | Fl i
+.Op Fl dPRrvWx
+.Ar
+.Sh DESCRIPTION
+The
+.Nm
+utility attempts to remove the non-directory type files specified on the
+command line.
+If the permissions of the file do not permit writing, and the standard
+input device is a terminal, the user is prompted (on the standard error
+output) for confirmation.
+.Pp
+The options are as follows:
+.Bl -tag -width flag
+.It Fl d
+Attempt to remove directories as well as other types of files.
+.It Fl f
+Attempt to remove the files without prompting for confirmation,
+regardless of the file's permissions.
+If the file does not exist, do not display a diagnostic message or modify
+the exit status to reflect an error.
+The
+.Fl f
+option overrides any previous
+.Fl i
+options.
+.It Fl i
+Request confirmation before attempting to remove each file, regardless of
+the file's permissions, or whether or not the standard input device is a
+terminal.
+The
+.Fl i
+option overrides any previous
+.Fl f
+options.
+.It Fl P
+Overwrite regular files before deleting them.
+Files are overwritten three times, first with the byte pattern 0xff,
+then 0x00, and then with random data, before they are deleted.
+Some care is taken to ensure that the data are actually written to
+disk, but this cannot be guaranteed, even on traditional filesystems;
+on log-structured filesystems or if any block-journaling scheme is
+in use, this option is completely useless.
+If the file cannot be
+overwritten, it will not be removed.
+.It Fl R
+Attempt to remove the file hierarchy rooted in each file argument.
+The
+.Fl R
+option implies the
+.Fl d
+option.
+If the
+.Fl i
+option is specified, the user is prompted for confirmation before
+each directory's contents are processed (as well as before the attempt
+is made to remove the directory).
+If the user does not respond affirmatively, the file hierarchy rooted in
+that directory is skipped.
+.It Fl r
+Equivalent to
+.Fl R .
+.It Fl v
+Cause
+.Nm
+to be verbose, showing files as they are processed.
+.It Fl W
+Attempts to undelete the named files.
+Currently, this option can only be used to recover
+files covered by whiteouts.
+.It Fl x
+When removing a hierarchy, do not cross mount points.
+.El
+.Pp
+The
+.Nm
+utility removes symbolic links, not the files referenced by the links.
+.Pp
+It is an error to attempt to remove the files ``.'' and ``..''.
+.Sh EXIT STATUS
+The
+.Nm
+utility exits 0 if all of the named files or file hierarchies were removed,
+or if the
+.Fl f
+option was specified and all of the existing files or file hierarchies were
+removed.
+If an error occurs,
+.Nm
+exits with a value >0.
+.Sh EXAMPLES
+.Nm
+uses
+.Xr getopt 3
+standard argument processing.
+Removing filenames that begin with a dash
+.Pq e.g., Ar -file
+in the current directory which might otherwise be taken as option flags to
+.Nm
+can be accomplished as follows:
+.Pp
+.Ic "rm -- -file"
+.Pp
+or
+.Pp
+.Ic "rm ./-file"
+.Sh COMPATIBILITY
+The
+.Nm
+utility differs from historical implementations in that the
+.Fl f
+option only masks attempts to remove non-existent files instead of
+masking a large variety of errors.
+.Pp
+Also, historical
+.Bx
+implementations prompted on the standard output,
+not the standard error output.
+.Sh SEE ALSO
+.Xr rmdir 1 ,
+.Xr undelete 2 ,
+.Xr unlink 2 ,
+.Xr fts 3 ,
+.Xr getopt 3 ,
+.Xr symlink 7
+.Sh STANDARDS
+The
+.Nm
+utility is expected to be
+.St -p1003.2
+compatible.
+The
+.Fl v
+and
+.Fl x
+options are extensions.
+.Pp
+The
+.Fl P
+option attempts to conform to U.S. DoD 5220-22.M, "National Industrial
+Security Program Operating Manual" ("NISPOM") as updated by Change
+2 and the July 23, 2003 "Clearing & Sanitization Matrix".
+However, unlike earlier revisions of NISPOM, the 2003 matrix imposes
+requirements which make it clear that the standard does not and
+can not apply to the erasure of individual files, in particular
+requirements relating to spare sector management for an entire
+magnetic disk.
+.Em Because these requirements are not met, the
+.Fl P
+.Em option does not conform to the standard .
+.Sh HISTORY
+An
+.Nm
+utility appeared in
+.At v1 .
+.Sh BUGS
+The
+.Fl P
+option assumes that the underlying file system is a fixed-block file
+system.
+FFS is a fixed-block file system, LFS is not.
+In addition, only regular files are overwritten, other types of files
+are not.
+Recent research indicates that as many as 35 overwrite passes with
+carefully chosen data patterns may be necessary to actually prevent
+recovery of data from a magnetic disk.
+Thus the
+.Fl P
+option is likely both insufficient for its design purpose and far
+too costly for default operation.
+However, it will at least prevent the recovery of data from FFS
+volumes with
+.Xr fsdb 8 .
diff --git a/bin/rm/rm.c b/bin/rm/rm.c
new file mode 100644
index 0000000..c1d2e8d
--- /dev/null
+++ b/bin/rm/rm.c
@@ -0,0 +1,611 @@
+/* $NetBSD: rm.c,v 1.53 2013/04/26 18:43:22 christos Exp $ */
+
+/*-
+ * Copyright (c) 1990, 1993, 1994, 2003
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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/cdefs.h>
+#ifndef lint
+__COPYRIGHT("@(#) Copyright (c) 1990, 1993, 1994\
+ The Regents of the University of California.  All rights reserved.");
+#endif /* not lint */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)rm.c	8.8 (Berkeley) 4/27/95";
+#else
+__RCSID("$NetBSD: rm.c,v 1.53 2013/04/26 18:43:22 christos Exp $");
+#endif
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <fts.h>
+#include <grp.h>
+#include <locale.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static int dflag, eval, fflag, iflag, Pflag, stdin_ok, vflag, Wflag;
+static int xflag;
+static sig_atomic_t pinfo;
+
+static int	check(char *, char *, struct stat *);
+static void	checkdot(char **);
+static void	progress(int);
+static void	rm_file(char **);
+static int	rm_overwrite(char *, struct stat *);
+static void	rm_tree(char **);
+__dead static void	usage(void);
+
+/*
+ * For the sake of the `-f' flag, check whether an error number indicates the
+ * failure of an operation due to an non-existent file, either per se (ENOENT)
+ * or because its filename argument was illegal (ENAMETOOLONG, ENOTDIR).
+ */
+#define NONEXISTENT(x) \
+    ((x) == ENOENT || (x) == ENAMETOOLONG || (x) == ENOTDIR)
+
+/*
+ * rm --
+ *	This rm is different from historic rm's, but is expected to match
+ *	POSIX 1003.2 behavior.  The most visible difference is that -f
+ *	has two specific effects now, ignore non-existent files and force
+ * 	file removal.
+ */
+int
+main(int argc, char *argv[])
+{
+	int ch, rflag;
+
+	setprogname(argv[0]);
+	(void)setlocale(LC_ALL, "");
+
+	Pflag = rflag = xflag = 0;
+	while ((ch = getopt(argc, argv, "dfiPRrvWx")) != -1)
+		switch (ch) {
+		case 'd':
+			dflag = 1;
+			break;
+		case 'f':
+			fflag = 1;
+			iflag = 0;
+			break;
+		case 'i':
+			fflag = 0;
+			iflag = 1;
+			break;
+		case 'P':
+			Pflag = 1;
+			break;
+		case 'R':
+		case 'r':			/* Compatibility. */
+			rflag = 1;
+			break;
+		case 'v':
+			vflag = 1;
+			break;
+		case 'x':
+			xflag = 1;
+			break;
+		case 'W':
+			Wflag = 1;
+			break;
+		case '?':
+		default:
+			usage();
+		}
+	argc -= optind;
+	argv += optind;
+
+	if (argc < 1) {
+		if (fflag)
+			return 0;
+		usage();
+	}
+
+	(void)signal(SIGINFO, progress);
+
+	checkdot(argv);
+
+	if (*argv) {
+		stdin_ok = isatty(STDIN_FILENO);
+
+		if (rflag)
+			rm_tree(argv);
+		else
+			rm_file(argv);
+	}
+
+	exit(eval);
+	/* NOTREACHED */
+}
+
+static void
+rm_tree(char **argv)
+{
+	FTS *fts;
+	FTSENT *p;
+	int flags, needstat, rval;
+			
+	/*
+	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
+	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
+	 */
+	needstat = !fflag && !iflag && stdin_ok;
+
+	/*
+	 * If the -i option is specified, the user can skip on the pre-order
+	 * visit.  The fts_number field flags skipped directories.
+	 */
+#define	SKIPPED	1
+
+	flags = FTS_PHYSICAL;
+	if (!needstat)
+		flags |= FTS_NOSTAT;
+	if (Wflag)
+		flags |= FTS_WHITEOUT;
+	if (xflag)
+		flags |= FTS_XDEV;
+	if ((fts = fts_open(argv, flags, NULL)) == NULL)
+		err(1, "fts_open failed");
+	while ((p = fts_read(fts)) != NULL) {
+	
+		switch (p->fts_info) {
+		case FTS_DNR:
+			if (!fflag || p->fts_errno != ENOENT) {
+				warnx("%s: %s", p->fts_path,
+						strerror(p->fts_errno));
+				eval = 1;
+			}
+			continue;
+		case FTS_ERR:
+			errx(EXIT_FAILURE, "%s: %s", p->fts_path,
+					strerror(p->fts_errno));
+			/* NOTREACHED */
+		case FTS_NS:
+			/*
+			 * FTS_NS: assume that if can't stat the file, it
+			 * can't be unlinked.
+			 */
+			if (fflag && NONEXISTENT(p->fts_errno))
+				continue;
+			if (needstat) {
+				warnx("%s: %s", p->fts_path,
+						strerror(p->fts_errno));
+				eval = 1;
+				continue;
+			}
+			break;
+		case FTS_D:
+			/* Pre-order: give user chance to skip. */
+			if (!fflag && !check(p->fts_path, p->fts_accpath,
+			    p->fts_statp)) {
+				(void)fts_set(fts, p, FTS_SKIP);
+				p->fts_number = SKIPPED;
+			}
+			continue;
+		case FTS_DP:
+			/* Post-order: see if user skipped. */
+			if (p->fts_number == SKIPPED)
+				continue;
+			break;
+		default:
+			if (!fflag &&
+			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
+				continue;
+		}
+
+		rval = 0;
+		/*
+		 * If we can't read or search the directory, may still be
+		 * able to remove it.  Don't print out the un{read,search}able
+		 * message unless the remove fails.
+		 */
+		switch (p->fts_info) {
+		case FTS_DP:
+		case FTS_DNR:
+			rval = rmdir(p->fts_accpath);
+			if (rval != 0 && fflag && errno == ENOENT)
+				continue;
+			break;
+
+		case FTS_W:
+			rval = undelete(p->fts_accpath);
+			if (rval != 0 && fflag && errno == ENOENT)
+				continue;
+			break;
+
+		default:
+			if (Pflag) {
+				if (rm_overwrite(p->fts_accpath, NULL))
+					continue;
+			}
+			rval = unlink(p->fts_accpath);
+			if (rval != 0 && fflag && NONEXISTENT(errno))
+				continue;
+			break;
+		}
+		if (rval != 0) {
+			warn("%s", p->fts_path);
+			eval = 1;
+		} else if (vflag || pinfo) {
+			pinfo = 0;
+			(void)printf("%s\n", p->fts_path);
+		}
+	}
+	if (errno)
+		err(1, "fts_read");
+	fts_close(fts);
+}
+
+static void
+rm_file(char **argv)
+{
+	struct stat sb;
+	int rval;
+	char *f;
+
+	/*
+	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
+	 * to remove a directory is an error, so must always stat the file.
+	 */
+	while ((f = *argv++) != NULL) {
+		/* Assume if can't stat the file, can't unlink it. */
+		if (lstat(f, &sb)) {
+			if (Wflag) {
+				sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
+			} else {
+				if (!fflag || !NONEXISTENT(errno)) {
+					warn("%s", f);
+					eval = 1;
+				}
+				continue;
+			}
+		} else if (Wflag) {
+			warnx("%s: %s", f, strerror(EEXIST));
+			eval = 1;
+			continue;
+		}
+
+		if (S_ISDIR(sb.st_mode) && !dflag) {
+			warnx("%s: is a directory", f);
+			eval = 1;
+			continue;
+		}
+		if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
+			continue;
+		if (S_ISWHT(sb.st_mode))
+			rval = undelete(f);
+		else if (S_ISDIR(sb.st_mode))
+			rval = rmdir(f);
+		else {
+			if (Pflag) {
+				if (rm_overwrite(f, &sb))
+					continue;
+			}
+			rval = unlink(f);
+		}
+		if (rval && (!fflag || !NONEXISTENT(errno))) {
+			warn("%s", f);
+			eval = 1;
+		}
+		if (vflag && rval == 0)
+			(void)printf("%s\n", f);
+	}
+}
+
+/*
+ * rm_overwrite --
+ *	Overwrite the file 3 times with varying bit patterns.
+ *
+ * This is an expensive way to keep people from recovering files from your
+ * non-snapshotted FFS filesystems using fsdb(8).  Really.  No more.  Only
+ * regular files are deleted, directories (and therefore names) will remain.
+ * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
+ * System V file system).  In a logging file system, you'll have to have
+ * kernel support.
+ *
+ * A note on standards:  U.S. DoD 5220.22-M "National Industrial Security
+ * Program Operating Manual" ("NISPOM") is often cited as a reference
+ * for clearing and sanitizing magnetic media.  In fact, a matrix of
+ * "clearing" and "sanitization" methods for various media was given in
+ * Chapter 8 of the original 1995 version of NISPOM.  However, that
+ * matrix was *removed from the document* when Chapter 8 was rewritten
+ * in Change 2 to the document in 2001.  Recently, the Defense Security
+ * Service has made a revised clearing and sanitization matrix available
+ * in Microsoft Word format on the DSS web site.  The standardization
+ * status of this matrix is unclear.  Furthermore, one must be very
+ * careful when referring to this matrix: it is intended for the "clearing"
+ * prior to reuse or "sanitization" prior to disposal of *entire media*,
+ * not individual files and the only non-physically-destructive method of
+ * "sanitization" that is permitted for magnetic disks of any kind is
+ * specifically noted to be prohibited for media that have contained
+ * Top Secret data.
+ *
+ * It is impossible to actually conform to the exact procedure given in
+ * the matrix if one is overwriting a file, not an entire disk, because
+ * the procedure requires examination and comparison of the disk's defect
+ * lists.  Any program that claims to securely erase *files* while 
+ * conforming to the standard, then, is not correct.  We do as much of
+ * what the standard requires as can actually be done when erasing a
+ * file, rather than an entire disk; but that does not make us conformant.
+ *
+ * Furthermore, the presence of track caches, disk and controller write
+ * caches, and so forth make it extremely difficult to ensure that data
+ * have actually been written to the disk, particularly when one tries
+ * to repeatedly overwrite the same sectors in quick succession.  We call
+ * fsync(), but controllers with nonvolatile cache, as well as IDE disks
+ * that just plain lie about the stable storage of data, will defeat this.
+ *
+ * Finally, widely respected research suggests that the given procedure
+ * is nowhere near sufficient to prevent the recovery of data using special
+ * forensic equipment and techniques that are well-known.  This is 
+ * presumably one reason that the matrix requires physical media destruction,
+ * rather than any technique of the sort attempted here, for secret data.
+ *
+ * Caveat Emptor.
+ *
+ * rm_overwrite will return 0 on success.
+ */
+
+static int
+rm_overwrite(char *file, struct stat *sbp)
+{
+	struct stat sb, sb2;
+	int fd, randint;
+	char randchar;
+
+	fd = -1;
+	if (sbp == NULL) {
+		if (lstat(file, &sb))
+			goto err;
+		sbp = &sb;
+	}
+	if (!S_ISREG(sbp->st_mode))
+		return 0;
+
+	/* flags to try to defeat hidden caching by forcing seeks */
+	if ((fd = open(file, O_RDWR|O_SYNC|O_RSYNC|O_NOFOLLOW, 0)) == -1)
+		goto err;
+
+	if (fstat(fd, &sb2)) {
+		goto err;
+	}
+
+	if (sb2.st_dev != sbp->st_dev || sb2.st_ino != sbp->st_ino ||
+	    !S_ISREG(sb2.st_mode)) {
+		errno = EPERM;
+		goto err;
+	}
+
+#define RAND_BYTES	1
+#define THIS_BYTE	0
+
+#define	WRITE_PASS(mode, byte) do {					\
+	off_t len;							\
+	size_t wlen, i;							\
+	char buf[8 * 1024];						\
+									\
+	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))			\
+		goto err;						\
+									\
+	if (mode == THIS_BYTE)						\
+		memset(buf, byte, sizeof(buf));				\
+	for (len = sbp->st_size; len > 0; len -= wlen) {		\
+		if (mode == RAND_BYTES) {				\
+			for (i = 0; i < sizeof(buf); 			\
+			    i+= sizeof(u_int32_t))			\
+				*(int *)(buf + i) = arc4random();	\
+		}							\
+		wlen = len < (off_t)sizeof(buf) ? (size_t)len : sizeof(buf); \
+		if ((size_t)write(fd, buf, wlen) != wlen)		\
+			goto err;					\
+	}								\
+	sync();		/* another poke at hidden caches */		\
+} while (/* CONSTCOND */ 0)
+
+#define READ_PASS(byte) do {						\
+	off_t len;							\
+	size_t rlen;							\
+	char pattern[8 * 1024];						\
+	char buf[8 * 1024];						\
+									\
+	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))			\
+		goto err;						\
+									\
+	memset(pattern, byte, sizeof(pattern));				\
+	for(len = sbp->st_size; len > 0; len -= rlen) {			\
+		rlen = len < (off_t)sizeof(buf) ? (size_t)len : sizeof(buf); \
+		if((size_t)read(fd, buf, rlen) != rlen)			\
+			goto err;					\
+		if(memcmp(buf, pattern, rlen))				\
+			goto err;					\
+	}								\
+	sync();		/* another poke at hidden caches */		\
+} while (/* CONSTCOND */ 0)
+
+	/*
+	 * DSS sanitization matrix "clear" for magnetic disks: 
+	 * option 'c' "Overwrite all addressable locations with a single 
+	 * character."
+	 */
+	randint = arc4random();
+	randchar = *(char *)&randint;
+	WRITE_PASS(THIS_BYTE, randchar);
+
+	/*
+	 * DSS sanitization matrix "sanitize" for magnetic disks: 
+	 * option 'd', sub 2 "Overwrite all addressable locations with a
+	 * character, then its complement.  Verify "complement" character
+	 * was written successfully to all addressable locations, then
+	 * overwrite all addressable locations with random characters; or
+	 * verify third overwrite of random characters."  The rest of the
+	 * text in d-sub-2 specifies requirements for overwriting spared
+	 * sectors; we cannot conform to it when erasing only a file, thus
+	 * we do not conform to the standard.
+	 */
+
+	/* 1. "a character" */
+	WRITE_PASS(THIS_BYTE, 0xff);
+
+	/* 2. "its complement" */
+	WRITE_PASS(THIS_BYTE, 0x00);
+
+	/* 3. "Verify 'complement' character" */
+	READ_PASS(0x00);
+
+	/* 4. "overwrite all addressable locations with random characters" */
+
+	WRITE_PASS(RAND_BYTES, 0x00);
+
+	/*
+	 * As the file might be huge, and we note that this revision of
+	 * the matrix says "random characters", not "a random character"
+	 * as the original did, we do not verify the random-character
+	 * write; the "or" in the standard allows this.
+	 */
+
+	if (close(fd) == -1) {
+		fd = -1;
+		goto err;
+	}
+
+	return 0;
+
+err:	eval = 1;
+	warn("%s", file);
+	if (fd != -1)
+		close(fd);
+	return 1;
+}
+
+static int
+check(char *path, char *name, struct stat *sp)
+{
+	int ch, first;
+	char modep[15];
+
+	/* Check -i first. */
+	if (iflag)
+		(void)fprintf(stderr, "remove '%s'? ", path);
+	else {
+		/*
+		 * If it's not a symbolic link and it's unwritable and we're
+		 * talking to a terminal, ask.  Symbolic links are excluded
+		 * because their permissions are meaningless.  Check stdin_ok
+		 * first because we may not have stat'ed the file.
+		 */
+		if (!stdin_ok || S_ISLNK(sp->st_mode) ||
+		    !(access(name, W_OK) && (errno != ETXTBSY)))
+			return (1);
+		strmode(sp->st_mode, modep);
+		if (Pflag) {
+			warnx(
+			    "%s: -P was specified but file could not"
+			    " be overwritten", path);
+			return 0;
+		}
+		(void)fprintf(stderr, "override %s%s%s:%s for '%s'? ",
+		    modep + 1, modep[9] == ' ' ? "" : " ",
+		    user_from_uid(sp->st_uid, 0),
+		    group_from_gid(sp->st_gid, 0), path);
+	}
+	(void)fflush(stderr);
+
+	first = ch = getchar();
+	while (ch != '\n' && ch != EOF)
+		ch = getchar();
+	return (first == 'y' || first == 'Y');
+}
+
+/*
+ * POSIX.2 requires that if "." or ".." are specified as the basename
+ * portion of an operand, a diagnostic message be written to standard
+ * error and nothing more be done with such operands.
+ *
+ * Since POSIX.2 defines basename as the final portion of a path after
+ * trailing slashes have been removed, we'll remove them here.
+ */
+#define ISDOT(a) ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
+static void
+checkdot(char **argv)
+{
+	char *p, **save, **t;
+	int complained;
+
+	complained = 0;
+	for (t = argv; *t;) {
+		/* strip trailing slashes */
+		p = strrchr(*t, '\0');
+		while (--p > *t && *p == '/')
+			*p = '\0';
+
+		/* extract basename */
+		if ((p = strrchr(*t, '/')) != NULL)
+			++p;
+		else
+			p = *t;
+
+		if (ISDOT(p)) {
+			if (!complained++)
+				warnx("\".\" and \"..\" may not be removed");
+			eval = 1;
+			for (save = t; (t[0] = t[1]) != NULL; ++t)
+				continue;
+			t = save;
+		} else
+			++t;
+	}
+}
+
+static void
+usage(void)
+{
+
+	(void)fprintf(stderr, "usage: %s [-f|-i] [-dPRrvWx] file ...\n",
+	    getprogname());
+	exit(1);
+	/* NOTREACHED */
+}
+
+static void
+progress(int sig __unused)
+{
+	
+	pinfo++;
+}