OpenBSD-4.6/bin/rm/rm.c
/* $OpenBSD: rm.c,v 1.22 2008/06/10 17:14:16 otto Exp $ */
/* $NetBSD: rm.c,v 1.19 1995/09/07 06:48:50 jtc Exp $ */
/*-
* Copyright (c) 1990, 1993, 1994
* 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.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1990, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)rm.c 8.8 (Berkeley) 4/27/95";
#else
static char rcsid[] = "$OpenBSD: rm.c,v 1.22 2008/06/10 17:14:16 otto Exp $";
#endif
#endif /* not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <locale.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <fts.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
extern char *__progname;
int dflag, eval, fflag, iflag, Pflag, stdin_ok;
int check(char *, char *, struct stat *);
void checkdot(char **);
void rm_file(char **);
int rm_overwrite(char *, struct stat *);
int pass(int, int, off_t, char *, size_t);
void rm_tree(char **);
void usage(void);
/*
* 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;
setlocale(LC_ALL, "");
Pflag = rflag = 0;
while ((ch = getopt(argc, argv, "dfiPRr")) != -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;
default:
usage();
}
argc -= optind;
argv += optind;
if (argc < 1 && fflag == 0)
usage();
checkdot(argv);
if (*argv) {
stdin_ok = isatty(STDIN_FILENO);
if (rflag)
rm_tree(argv);
else
rm_file(argv);
}
exit (eval);
}
void
rm_tree(char **argv)
{
FTS *fts;
FTSENT *p;
int needstat;
int flags;
/*
* 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 (!(fts = fts_open(argv, flags, NULL)))
err(1, NULL);
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(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
case FTS_NS:
/*
* FTS_NS: assume that if can't stat the file, it
* can't be unlinked.
*/
if (!needstat)
break;
if (!fflag || p->fts_errno != ENOENT) {
warnx("%s: %s",
p->fts_path, strerror(p->fts_errno));
eval = 1;
}
continue;
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;
}
/*
* 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:
if (!rmdir(p->fts_accpath) ||
(fflag && errno == ENOENT))
continue;
break;
default:
if (Pflag)
rm_overwrite(p->fts_accpath, NULL);
if (!unlink(p->fts_accpath) ||
(fflag && errno == ENOENT))
continue;
}
warn("%s", p->fts_path);
eval = 1;
}
if (errno)
err(1, "fts_read");
fts_close(fts);
}
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 (!fflag || errno != ENOENT) {
warn("%s", f);
eval = 1;
}
continue;
}
if (S_ISDIR(sb.st_mode) && !dflag) {
warnx("%s: is a directory", f);
eval = 1;
continue;
}
if (!fflag && !check(f, f, &sb))
continue;
else if (S_ISDIR(sb.st_mode))
rval = rmdir(f);
else {
if (Pflag)
rm_overwrite(f, &sb);
rval = unlink(f);
}
if (rval && (!fflag || errno != ENOENT)) {
warn("%s", f);
eval = 1;
}
}
}
/*
* rm_overwrite --
* Overwrite the file 3 times with varying bit patterns.
*
* XXX
* This is a cheap way to *really* delete files. Note that 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.
* Returns 1 for success.
*/
int
rm_overwrite(char *file, struct stat *sbp)
{
struct stat sb;
struct statfs fsb;
size_t bsize;
int fd;
char *buf = NULL;
fd = -1;
if (sbp == NULL) {
if (lstat(file, &sb))
goto err;
sbp = &sb;
}
if (!S_ISREG(sbp->st_mode))
return (1);
if (sbp->st_nlink > 1) {
warnx("%s (inode %u): not overwritten due to multiple links",
file, sbp->st_ino);
return (0);
}
if ((fd = open(file, O_WRONLY, 0)) == -1)
goto err;
if (fstatfs(fd, &fsb) == -1)
goto err;
bsize = MAX(fsb.f_iosize, 1024U);
if ((buf = malloc(bsize)) == NULL)
err(1, "%s: malloc", file);
if (!pass(0xff, fd, sbp->st_size, buf, bsize) || fsync(fd) ||
lseek(fd, (off_t)0, SEEK_SET))
goto err;
if (!pass(0x00, fd, sbp->st_size, buf, bsize) || fsync(fd) ||
lseek(fd, (off_t)0, SEEK_SET))
goto err;
if (!pass(0xff, fd, sbp->st_size, buf, bsize) || fsync(fd))
goto err;
close(fd);
free(buf);
return (1);
err:
warn("%s", file);
close(fd);
eval = 1;
free(buf);
return (0);
}
int
pass(int val, int fd, off_t len, char *buf, size_t bsize)
{
size_t wlen;
memset(buf, val, bsize);
for (; len > 0; len -= wlen) {
wlen = len < bsize ? len : bsize;
if (write(fd, buf, wlen) != wlen)
return (0);
}
return (1);
}
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 != EACCES)
return (1);
strmode(sp->st_mode, modep);
(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])))
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;
}
}
void
usage(void)
{
(void)fprintf(stderr, "usage: %s [-dfiPRr] file ...\n", __progname);
exit(1);
}