/bin/rm: fix removing symlinks with uchg/uappnd set
[dragonfly.git] / bin / rm / rm.c
CommitLineData
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1/*-
2 * Copyright (c) 1990, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
1de703da
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32 *
33 * @(#) Copyright (c) 1990, 1993, 1994 The Regents of the University of California. All rights reserved.
34 * @(#)rm.c 8.5 (Berkeley) 4/18/94
35 * $FreeBSD: src/bin/rm/rm.c,v 1.29.2.5 2002/07/12 07:25:48 tjr Exp $
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36 */
37
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38#include <sys/stat.h>
39#include <sys/param.h>
40#include <sys/mount.h>
68c91344 41#include <sys/ioctl.h>
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42
43#include <err.h>
44#include <errno.h>
45#include <fcntl.h>
46#include <fts.h>
5b0d3e5e
SW
47#include <grp.h>
48#include <pwd.h>
1d2358df 49#include <signal.h>
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50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <sysexits.h>
54#include <unistd.h>
55
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VBD
56static int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
57static int rflag, Iflag;
58static uid_t uid;
59volatile sig_atomic_t info;
984263bc 60
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LF
61static int check(const char *, const char *, struct stat *);
62static int check2(char **);
63static void checkdot(char **);
64static void rm_file(char **);
65static int rm_overwrite(const char *, struct stat *);
66static void rm_tree(char **);
1d2358df 67static void siginfo(int);
e13bfb74 68static void usage(void);
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69
70/*
71 * rm --
72 * This rm is different from historic rm's, but is expected to match
73 * POSIX 1003.2 behavior. The most visible difference is that -f
74 * has two specific effects now, ignore non-existent files and force
75 * file removal.
76 */
77int
78main(int argc, char *argv[])
79{
28242317 80 int ch;
620ab84e 81 const char *p;
68c91344 82 pid_t tty_pgrp;
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83
84 /*
85 * Test for the special case where the utility is called as
86 * "unlink", for which the functionality provided is greatly
87 * simplified.
88 */
17b61719 89 if ((p = strrchr(argv[0], '/')) == NULL)
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90 p = argv[0];
91 else
92 ++p;
93 if (strcmp(p, "unlink") == 0) {
94 while (getopt(argc, argv, "") != -1)
95 usage();
96 argc -= optind;
97 argv += optind;
98 if (argc != 1)
99 usage();
100 rm_file(&argv[0]);
101 exit(eval);
102 }
103
104 Pflag = rflag = 0;
64a3a712 105 while ((ch = getopt(argc, argv, "dfiIPRrvW")) != -1) {
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106 switch(ch) {
107 case 'd':
108 dflag = 1;
109 break;
110 case 'f':
111 fflag = 1;
112 iflag = 0;
113 break;
114 case 'i':
115 fflag = 0;
116 iflag = 1;
117 break;
28242317 118 case 'I':
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119 /*
120 * The -I flag is intended to be generally aliasable
121 * in /etc/csh.cshrc. We apply it only to foreground
122 * processes.
123 */
124 if (ioctl(0, TIOCGPGRP, &tty_pgrp) == 0) {
125 if (tty_pgrp == getpgrp())
126 Iflag = 1;
127 }
28242317 128 break;
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129 case 'P':
130 Pflag = 1;
131 break;
132 case 'R':
133 case 'r': /* Compatibility. */
134 rflag = 1;
135 break;
136 case 'v':
137 vflag = 1;
138 break;
139 case 'W':
140 Wflag = 1;
141 break;
142 default:
143 usage();
144 }
64a3a712 145 }
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146 argc -= optind;
147 argv += optind;
148
149 if (argc < 1) {
150 if (fflag)
151 return 0;
152 usage();
153 }
154
155 checkdot(argv);
156 uid = geteuid();
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VBD
157
158 signal(SIGINFO, siginfo);
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159
160 if (*argv) {
161 stdin_ok = isatty(STDIN_FILENO);
162
64a3a712 163 if (Iflag && !iflag) {
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164 if (check2(argv) == 0)
165 exit (1);
166 }
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167 if (rflag)
168 rm_tree(argv);
169 else
170 rm_file(argv);
171 }
172
173 exit (eval);
174}
175
e13bfb74 176static void
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177rm_tree(char **argv)
178{
179 FTS *fts;
180 FTSENT *p;
181 int needstat;
182 int flags;
183 int rval;
184
185 /*
186 * Remove a file hierarchy. If forcing removal (-f), or interactive
187 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
188 */
189 needstat = !uid || (!fflag && !iflag && stdin_ok);
190
191 /*
192 * If the -i option is specified, the user can skip on the pre-order
193 * visit. The fts_number field flags skipped directories.
194 */
195#define SKIPPED 1
196
197 flags = FTS_PHYSICAL;
198 if (!needstat)
199 flags |= FTS_NOSTAT;
200 if (Wflag)
201 flags |= FTS_WHITEOUT;
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LF
202 if ((fts = fts_open(argv, flags, NULL)) == NULL) {
203 if (fflag && errno == ENOENT)
204 return;
984263bc 205 err(1, NULL);
620ab84e 206 }
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207 while ((p = fts_read(fts)) != NULL) {
208 switch (p->fts_info) {
209 case FTS_DNR:
210 if (!fflag || p->fts_errno != ENOENT) {
211 warnx("%s: %s",
212 p->fts_path, strerror(p->fts_errno));
213 eval = 1;
214 }
215 continue;
216 case FTS_ERR:
217 errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
218 case FTS_NS:
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219 /*
220 * Assume that since fts_read() couldn't stat
221 * the file, it can't be unlinked.
222 */
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223 if (!needstat)
224 break;
225 if (!fflag || p->fts_errno != ENOENT) {
226 warnx("%s: %s",
227 p->fts_path, strerror(p->fts_errno));
228 eval = 1;
229 }
230 continue;
231 case FTS_D:
232 /* Pre-order: give user chance to skip. */
233 if (!fflag && !check(p->fts_path, p->fts_accpath,
234 p->fts_statp)) {
57fed2af 235 fts_set(fts, p, FTS_SKIP);
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236 p->fts_number = SKIPPED;
237 }
238 else if (!uid &&
239 (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
240 !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
cbe044e0 241 lchflags(p->fts_accpath,
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242 p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
243 goto err;
244 continue;
245 case FTS_DP:
246 /* Post-order: see if user skipped. */
247 if (p->fts_number == SKIPPED)
248 continue;
249 break;
250 default:
251 if (!fflag &&
252 !check(p->fts_path, p->fts_accpath, p->fts_statp))
253 continue;
254 }
255
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256 if (info) {
257 info = 0;
258 fprintf(stderr, "Currently removing: %s\n", p->fts_path);
259 }
260
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261 rval = 0;
262 if (!uid &&
263 (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
264 !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
cbe044e0 265 rval = lchflags(p->fts_accpath,
984263bc 266 p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
1d2358df 267
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268 if (rval == 0) {
269 /*
270 * If we can't read or search the directory, may still be
271 * able to remove it. Don't print out the un{read,search}able
272 * message unless the remove fails.
273 */
274 switch (p->fts_info) {
275 case FTS_DP:
276 case FTS_DNR:
277 rval = rmdir(p->fts_accpath);
278 if (rval == 0 || (fflag && errno == ENOENT)) {
279 if (rval == 0 && vflag)
57fed2af 280 printf("%s\n",
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281 p->fts_path);
282 continue;
283 }
284 break;
285
286 case FTS_W:
287 rval = undelete(p->fts_accpath);
288 if (rval == 0 && (fflag && errno == ENOENT)) {
289 if (vflag)
57fed2af 290 printf("%s\n",
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291 p->fts_path);
292 continue;
293 }
294 break;
295
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296 case FTS_NS:
297 /*
298 * Assume that since fts_read() couldn't stat
299 * the file, it can't be unlinked.
300 */
301 if (fflag)
302 continue;
303 /* FALLTHROUGH */
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304 default:
305 if (Pflag)
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306 if (!rm_overwrite(p->fts_accpath, NULL))
307 continue;
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308 rval = unlink(p->fts_accpath);
309 if (rval == 0 || (fflag && errno == ENOENT)) {
310 if (rval == 0 && vflag)
57fed2af 311 printf("%s\n",
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312 p->fts_path);
313 continue;
314 }
315 }
316 }
317err:
318 warn("%s", p->fts_path);
319 eval = 1;
320 }
321 if (errno)
322 err(1, "fts_read");
356438f3 323 fts_close(fts);
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324}
325
e13bfb74 326static void
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327rm_file(char **argv)
328{
329 struct stat sb;
330 int rval;
620ab84e 331 const char *f;
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332
333 /*
334 * Remove a file. POSIX 1003.2 states that, by default, attempting
335 * to remove a directory is an error, so must always stat the file.
336 */
337 while ((f = *argv++) != NULL) {
1d2358df
VBD
338 if (info) {
339 info = 0;
340 fprintf(stderr, "Currently removing: %s\n", f);
341 }
342
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343 /* Assume if can't stat the file, can't unlink it. */
344 if (lstat(f, &sb)) {
345 if (Wflag) {
346 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
347 } else {
348 if (!fflag || errno != ENOENT) {
349 warn("%s", f);
350 eval = 1;
351 }
352 continue;
353 }
354 } else if (Wflag) {
355 warnx("%s: %s", f, strerror(EEXIST));
356 eval = 1;
357 continue;
358 }
359
360 if (S_ISDIR(sb.st_mode) && !dflag) {
361 warnx("%s: is a directory", f);
362 eval = 1;
363 continue;
364 }
365 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
366 continue;
367 rval = 0;
368 if (!uid &&
369 (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
370 !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
cbe044e0 371 rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
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372 if (rval == 0) {
373 if (S_ISWHT(sb.st_mode))
374 rval = undelete(f);
375 else if (S_ISDIR(sb.st_mode))
376 rval = rmdir(f);
377 else {
378 if (Pflag)
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LF
379 if (!rm_overwrite(f, &sb))
380 continue;
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MD
381 rval = unlink(f);
382 }
383 }
384 if (rval && (!fflag || errno != ENOENT)) {
385 warn("%s", f);
386 eval = 1;
387 }
388 if (vflag && rval == 0)
57fed2af 389 printf("%s\n", f);
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MD
390 }
391}
392
393/*
394 * rm_overwrite --
395 * Overwrite the file 3 times with varying bit patterns.
396 *
397 * XXX
398 * This is a cheap way to *really* delete files. Note that only regular
399 * files are deleted, directories (and therefore names) will remain.
400 * Also, this assumes a fixed-block filesystem (like FFS, or a V7 or a
401 * System V filesystem). In a logging filesystem, you'll have to have
402 * kernel support.
403 */
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LF
404static int
405rm_overwrite(const char *file, struct stat *sbp)
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MD
406{
407 struct stat sb;
408 struct statfs fsb;
409 off_t len;
410 int bsize, fd, wlen;
411 char *buf = NULL;
412
413 fd = -1;
414 if (sbp == NULL) {
415 if (lstat(file, &sb))
416 goto err;
417 sbp = &sb;
418 }
e13bfb74
LF
419 if (!S_ISREG(sbp->st_mode)) {
420 warnx("%s: cannot overwrite a non-regular file", file);
421 return (1);
422 }
336688f5 423 if (sbp->st_nlink > 1) {
eccf6cca
SW
424 warnx("%s (inode %ju): not overwritten due to multiple links",
425 file, (uintmax_t)sbp->st_ino);
336688f5
MD
426 return (0);
427 }
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MD
428 if ((fd = open(file, O_WRONLY, 0)) == -1)
429 goto err;
430 if (fstatfs(fd, &fsb) == -1)
431 goto err;
432 bsize = MAX(fsb.f_iosize, 1024);
433 if ((buf = malloc(bsize)) == NULL)
e13bfb74 434 err(1, "%s malloc failed", file);
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MD
435
436#define PASS(byte) { \
437 memset(buf, byte, bsize); \
438 for (len = sbp->st_size; len > 0; len -= wlen) { \
439 wlen = len < bsize ? len : bsize; \
440 if (write(fd, buf, wlen) != wlen) \
441 goto err; \
442 } \
443}
444 PASS(0xff);
445 if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
446 goto err;
447 PASS(0x00);
448 if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
449 goto err;
450 PASS(0xff);
451 if (!fsync(fd) && !close(fd)) {
452 free(buf);
e13bfb74 453 return (1);
984263bc
MD
454 }
455
456err: eval = 1;
457 if (buf)
458 free(buf);
e13bfb74
LF
459 if (fd != -1)
460 close(fd);
984263bc 461 warn("%s", file);
e13bfb74 462 return (0);
984263bc
MD
463}
464
465
e13bfb74
LF
466static int
467check(const char *path, const char *name, struct stat *sp)
984263bc 468{
799b8cd3
SS
469 static int perm_answer = -1;
470 struct choice {
471 int ch;
472 const char *str;
473 int res;
474 int perm;
475 } *choice, choices[] = {
476 { 'y', "yes" , 1, 0 },
477 { 'n', "no" , 0, 0 },
478 { 'a', "always", 1, 1 },
479 { 'v', "never" , 0, 1 },
480 { 0, NULL, 0, 0 }
481 };
984263bc
MD
482 char modep[15], *flagsp;
483
799b8cd3
SS
484 if (perm_answer != -1)
485 return (perm_answer);
486
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487 /* Check -i first. */
488 if (iflag)
57fed2af 489 fprintf(stderr, "remove %s? ", path);
984263bc
MD
490 else {
491 /*
492 * If it's not a symbolic link and it's unwritable and we're
493 * talking to a terminal, ask. Symbolic links are excluded
494 * because their permissions are meaningless. Check stdin_ok
495 * first because we may not have stat'ed the file.
e13bfb74 496 * Also skip this check if the -P option was specified because
860c2e6b
SS
497 * we will not be able to overwrite file contents and will
498 * barf later.
984263bc 499 */
e13bfb74 500 if (!stdin_ok || S_ISLNK(sp->st_mode) || Pflag ||
984263bc
MD
501 (!access(name, W_OK) &&
502 !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
503 (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
504 return (1);
505 strmode(sp->st_mode, modep);
506 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
507 err(1, NULL);
57fed2af 508 fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
984263bc
MD
509 modep + 1, modep[9] == ' ' ? "" : " ",
510 user_from_uid(sp->st_uid, 0),
511 group_from_gid(sp->st_gid, 0),
860c2e6b 512 *flagsp ? flagsp : "", *flagsp ? " " : "",
984263bc
MD
513 path);
514 free(flagsp);
515 }
57fed2af 516 fflush(stderr);
984263bc 517
799b8cd3
SS
518 for (;;) {
519 size_t len;
520 char *answer;
521
522 answer = fgetln(stdin, &len);
523 /* clearerr(stdin); */
524 if (answer == NULL)
525 return (0);
526 if (answer[len - 1] == '\n')
527 len--;
528 if (len == 0)
529 continue;
530
531 for (choice = choices; choice->str != NULL; choice++) {
532 if (len == 1 && choice->ch == answer[0])
533 goto valid_choice;
534 if (strncasecmp(answer, choice->str, len) == 0)
535 goto valid_choice;
536 }
537
538 fprintf(stderr, "invalid answer, try again (y/n/a/v): ");
539 }
540
541valid_choice:
542 if (choice->perm)
543 perm_answer = choice->res;
544 return (choice->res);
984263bc
MD
545}
546
e13bfb74 547static int
28242317
MD
548check2(char **argv)
549{
550 struct stat st;
551 int first;
552 int ch;
553 int fcount = 0;
554 int dcount = 0;
555 int i;
556 const char *dname = NULL;
557
558 for (i = 0; argv[i]; ++i) {
559 if (lstat(argv[i], &st) == 0) {
560 if (S_ISDIR(st.st_mode)) {
561 ++dcount;
562 dname = argv[i]; /* only used if 1 dir */
563 } else {
564 ++fcount;
565 }
566 }
567 }
568 first = 0;
569 while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
570 if (dcount && rflag) {
571 fprintf(stderr, "recursively remove");
572 if (dcount == 1)
573 fprintf(stderr, " %s", dname);
574 else
575 fprintf(stderr, " %d dirs", dcount);
576 if (fcount == 1)
577 fprintf(stderr, " and 1 file");
578 else if (fcount > 1)
579 fprintf(stderr, " and %d files", fcount);
580 } else if (dcount + fcount > 3) {
581 fprintf(stderr, "remove %d files", dcount + fcount);
582 } else {
583 return(1);
584 }
585 fprintf(stderr, "? ");
586 fflush(stderr);
587
588 first = ch = getchar();
589 while (ch != '\n' && ch != EOF)
590 ch = getchar();
982099ef
MD
591 if (ch == EOF)
592 break;
28242317
MD
593 }
594 return (first == 'y' || first == 'Y');
595}
596
984263bc 597#define ISDOT(a) ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
e13bfb74 598static void
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MD
599checkdot(char **argv)
600{
601 char *p, **save, **t;
602 int complained;
603
604 complained = 0;
605 for (t = argv; *t;) {
606 if ((p = strrchr(*t, '/')) != NULL)
607 ++p;
608 else
609 p = *t;
610 if (ISDOT(p)) {
611 if (!complained++)
612 warnx("\".\" and \"..\" may not be removed");
613 eval = 1;
614 for (save = t; (t[0] = t[1]) != NULL; ++t)
615 continue;
616 t = save;
617 } else
618 ++t;
619 }
620}
621
e13bfb74 622static void
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MD
623usage(void)
624{
625
57fed2af 626 fprintf(stderr, "%s\n%s\n",
4d996822 627 "usage: rm [-f | -i] [-dIPRrvW] file ...",
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MD
628 " unlink file");
629 exit(EX_USAGE);
630}
1d2358df
VBD
631
632static void
633siginfo(int notused __unused)
634{
635 info = 1;
636}