freebsd-dev/bin/rm/rm.c
1995-04-13 13:35:09 +00:00

416 lines
10 KiB
C

/*-
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* $Id: rm.c,v 1.5 1994/09/24 02:57:02 davidg Exp $
*/
#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
static char sccsid[] = "@(#)rm.c 8.5 (Berkeley) 4/18/94";
#endif /* not lint */
#include <sys/types.h>
#include <sys/stat.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>
extern char *flags_to_string __P((u_long, char *));
int dflag, eval, fflag, iflag, Pflag, stdin_ok;
uid_t uid;
int check __P((char *, char *, struct stat *));
void checkdot __P((char **));
void rm_file __P((char **));
void rm_overwrite __P((char *, struct stat *));
void rm_tree __P((char **));
void usage __P((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(argc, argv)
int argc;
char *argv[];
{
int ch, rflag;
Pflag = rflag = 0;
while ((ch = getopt(argc, argv, "dfiPRr")) != EOF)
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 '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc < 1)
usage();
checkdot(argv);
if (!*argv)
exit (eval);
stdin_ok = isatty(STDIN_FILENO);
uid = geteuid();
if (rflag)
rm_tree(argv);
else
rm_file(argv);
exit (eval);
}
void
rm_tree(argv)
char **argv;
{
FTS *fts;
FTSENT *p;
int needstat;
int 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 = !uid || !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
if (!(fts = fts_open(argv,
needstat ? FTS_PHYSICAL|FTS_NOCHDIR :
FTS_PHYSICAL|FTS_NOSTAT|FTS_NOCHDIR, (int (*)())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 (iflag && !check(p->fts_path, p->fts_accpath,
p->fts_statp)) {
(void)fts_set(fts, p, FTS_SKIP);
p->fts_number = SKIPPED;
}
else if (!uid &&
(p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
!(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
chflags(p->fts_accpath,
p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
goto err;
continue;
case FTS_DP:
/* Post-order: see if user skipped. */
if (p->fts_number == SKIPPED)
continue;
break;
}
if (!fflag &&
!check(p->fts_path, p->fts_accpath, p->fts_statp))
continue;
rval = 0;
if (!uid &&
(p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
!(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
rval = chflags(p->fts_accpath,
p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
if (!rval) {
/*
* 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.
*/
if (p->fts_info == FTS_DP || p->fts_info == FTS_DNR) {
if (!rmdir(p->fts_accpath))
continue;
if (errno == ENOENT) {
if (fflag)
continue;
} else if (p->fts_info != FTS_DP)
warnx("%s: unable to read", p->fts_path);
} else {
if (Pflag)
rm_overwrite(p->fts_accpath, NULL);
if (!unlink(p->fts_accpath) || (fflag && errno == ENOENT))
continue;
}
}
err:
warn("%s", p->fts_path);
eval = 1;
}
if (errno)
err(1, "fts_read");
}
void
rm_file(argv)
char **argv;
{
struct stat sb;
int df, rval;
char *f;
df = dflag;
/*
* 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) && !df) {
warnx("%s: is a directory", f);
eval = 1;
continue;
}
if (!fflag && !check(f, f, &sb))
continue;
rval = 0;
if (!uid &&
(sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
!(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
if (!rval) {
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.
*/
void
rm_overwrite(file, sbp)
char *file;
struct stat *sbp;
{
struct stat sb;
off_t len;
int fd, wlen;
char buf[8 * 1024];
fd = -1;
if (sbp == NULL) {
if (lstat(file, &sb))
goto err;
sbp = &sb;
}
if (!S_ISREG(sbp->st_mode))
return;
if ((fd = open(file, O_WRONLY, 0)) == -1)
goto err;
#define PASS(byte) { \
memset(buf, byte, sizeof(buf)); \
for (len = sbp->st_size; len > 0; len -= wlen) { \
wlen = len < sizeof(buf) ? len : sizeof(buf); \
if (write(fd, buf, wlen) != wlen) \
goto err; \
} \
}
PASS(0xff);
if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
goto err;
PASS(0x00);
if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
goto err;
PASS(0xff);
if (!fsync(fd) && !close(fd))
return;
err: eval = 1;
warn("%s", file);
}
int
check(path, name, sp)
char *path, *name;
struct stat *sp;
{
int ch, first;
char modep[15], flagsp[128];
/* 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) &&
!(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
(!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid))
return (1);
strmode(sp->st_mode, modep);
strcpy(flagsp, flags_to_string(sp->st_flags, NULL));
if (*flagsp)
strcat(flagsp, " ");
(void)fprintf(stderr, "override %s%s%s/%s %sfor %s? ",
modep + 1, modep[9] == ' ' ? "" : " ",
user_from_uid(sp->st_uid, 0),
group_from_gid(sp->st_gid, 0),
*flagsp ? flagsp : "",
path);
}
(void)fflush(stderr);
first = ch = getchar();
while (ch != '\n' && ch != EOF)
ch = getchar();
return (first == 'y');
}
#define ISDOT(a) ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
void
checkdot(argv)
char **argv;
{
char *p, **save, **t;
int complained;
complained = 0;
for (t = argv; *t;) {
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);
t = save;
} else
++t;
}
}
void
usage()
{
(void)fprintf(stderr, "usage: rm [-dfiRr] file ...\n");
exit(1);
}