/* remove.c -- core functions for removing files and directories Copyright (C) 88, 90, 91, 94, 95, 96, 97, 1998 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Extracted from rm.c and librarified by Jim Meyering. */ #ifdef _AIX #pragma alloca #endif #include #include #include #include #include "save-cwd.h" #include "system.h" #include "closeout.h" #include "error.h" #include "obstack.h" #include "hash.h" #include "remove.h" #define obstack_chunk_alloc malloc #define obstack_chunk_free free #ifndef PARAMS # if defined (__GNUC__) || __STDC__ # define PARAMS(args) args # else # define PARAMS(args) () # endif #endif #ifdef D_INO_IN_DIRENT # define D_INO(dp) ((dp)->d_ino) # define ENABLE_CYCLE_CHECK #else /* Some systems don't have inodes, so fake them to avoid lots of ifdefs. */ # define D_INO(dp) 1 #endif #if !defined (S_ISLNK) # define S_ISLNK(Mode) 0 #endif #define DOT_OR_DOTDOT(Basename) \ (Basename[0] == '.' && (Basename[1] == '\0' \ || (Basename[1] == '.' && Basename[2] == '\0'))) #if defined strdupa # define ASSIGN_STRDUPA(DEST, S) \ do { DEST = strdupa(S); } while (0) #else # define ASSIGN_STRDUPA(DEST, S) \ do \ { \ const char *s_ = (S); \ size_t len_ = strlen (s_) + 1; \ char *tmp_dest_ = (char *) alloca (len_); \ DEST = memcpy (tmp_dest_, (s_), len_); \ } \ while (0) #endif /* Initial capacity of per-directory hash table of entries that have been processed but not been deleted. */ #define HT_INITIAL_CAPACITY 13 /* Initial capacity of the active directory hash table. This table will be resized only for hierarchies more than about 45 levels deep. */ #define ACTIVE_DIR_INITIAL_CAPACITY 53 char *base_name (); int euidaccess (); int yesno (); extern char *program_name; /* state initialized by remove_init, freed by remove_fini */ /* An entry in the active_dir_map. */ struct active_dir_ent { ino_t inum; unsigned int depth; }; /* The name of the directory (starting with and relative to a command line argument) being processed. When a subdirectory is entered, a new component is appended (pushed). When RM chdir's out of a directory, the top component is removed (popped). This is used to form a full file name when necessary. */ static struct obstack dir_stack; /* Stack of lengths of directory names (including trailing slash) appended to dir_stack. We have to have a separate stack of lengths (rather than just popping back to previous slash) because the first element pushed onto the dir stack may contain slashes. */ static struct obstack len_stack; /* Set of `active' directories from the current command-line argument to the level in the hierarchy at which files are being removed. A directory is added to the active set when RM begins removing it (or its entries), and it is removed from the set just after RM has finished processing it. This is actually a map (not a set), implemented with a hash table. For each active directory, it maps the directory's inode number to the depth of that directory relative to the root of the tree being deleted. A directory specified on the command line has depth zero. This construct is used to detect directory cycles so that RM can warn about them rather than iterating endlessly. */ #ifdef ENABLE_CYCLE_CHECK static struct HT *active_dir_map; #endif static inline unsigned int current_depth (void) { return obstack_object_size (&len_stack) / sizeof (size_t); } static void print_nth_dir (FILE *stream, unsigned int depth) { size_t *length = (size_t *) obstack_base (&len_stack); char *dir_name = (char *) obstack_base (&dir_stack); unsigned int sum = 0; unsigned int i; assert (0 <= depth && depth < current_depth ()); for (i = 0; i <= depth; i++) { sum += length[i]; } fwrite (dir_name, 1, sum, stream); } static inline struct active_dir_ent * make_active_dir_ent (ino_t inum, unsigned int depth) { struct active_dir_ent *ent; ent = (struct active_dir_ent *) xmalloc (sizeof *ent); ent->inum = inum; ent->depth = depth; return ent; } static unsigned int hash_active_dir_ent (void const *x, unsigned int table_size) { struct active_dir_ent const *ade = x; return ade->inum % table_size; } static int hash_compare_active_dir_ents (void const *x, void const *y) { struct active_dir_ent const *a = x; struct active_dir_ent const *b = y; return (a->inum == b->inum ? 0 : 1); } /* A hash function for null-terminated char* strings using the method described in Aho, Sethi, & Ullman, p 436. */ static unsigned int hash_pjw (const void *x, unsigned int tablesize) { const char *s = x; unsigned int h = 0; unsigned int g; while (*s != 0) { h = (h << 4) + *s++; if ((g = h & (unsigned int) 0xf0000000) != 0) h = (h ^ (g >> 24)) ^ g; } return (h % tablesize); } static int hash_compare_strings (void const *x, void const *y) { return strcmp (x, y); } static inline void push_dir (const char *dir_name) { size_t len; len = strlen (dir_name); /* Append the string onto the stack. */ obstack_grow (&dir_stack, dir_name, len); /* Append a trailing slash. */ obstack_1grow (&dir_stack, '/'); /* Add one for the slash. */ ++len; /* Push the length (including slash) onto its stack. */ obstack_grow (&len_stack, &len, sizeof (len)); } static inline void pop_dir (void) { int n_lengths = obstack_object_size (&len_stack) / sizeof (size_t); size_t *length = (size_t *) obstack_base (&len_stack); size_t top_len; assert (n_lengths > 0); top_len = length[n_lengths - 1]; assert (top_len >= 2); /* Pop off the specified length of pathname. */ assert (obstack_object_size (&dir_stack) >= top_len); obstack_blank (&dir_stack, -top_len); /* Pop the length stack, too. */ assert (obstack_object_size (&len_stack) >= sizeof (size_t)); obstack_blank (&len_stack, -(sizeof (size_t))); } /* Copy the SRC_LEN bytes of data beginning at SRC into the DST_LEN-byte buffer, DST, so that the last source byte is at the end of the destination buffer. If SRC_LEN is longer than DST_LEN, then set *TRUNCATED to non-zero. Set *RESULT to point to the beginning of (the portion of) the source data in DST. Return the number of bytes remaining in the destination buffer. */ static size_t right_justify (char *dst, size_t dst_len, const char *src, size_t src_len, char **result, int *truncated) { const char *sp; char *dp; if (src_len <= dst_len) { sp = src; dp = dst + (dst_len - src_len); *truncated = 0; } else { sp = src + (src_len - dst_len); dp = dst; src_len = dst_len; *truncated = 1; } *result = memcpy (dp, sp, src_len); return dst_len - src_len; } /* Using the global directory name obstack, create the full path to FILENAME. Return it in sometimes-realloc'd space that should not be freed by the caller. Realloc as necessary. If realloc fails, use a static buffer and put as long a suffix in that buffer as possible. */ static char * full_filename (const char *filename) { static char *buf = NULL; static size_t n_allocated = 0; int dir_len = obstack_object_size (&dir_stack); char *dir_name = (char *) obstack_base (&dir_stack); size_t n_bytes_needed; size_t filename_len; filename_len = strlen (filename); n_bytes_needed = dir_len + filename_len + 1; if (n_bytes_needed > n_allocated) { /* This code requires that realloc accept NULL as the first arg. This function must not use xrealloc. Otherwise, an out-of-memory error involving a file name to be expanded here wouldn't ever be issued. Use realloc and fall back on using a static buffer if memory allocation fails. */ buf = realloc (buf, n_bytes_needed); n_allocated = n_bytes_needed; if (buf == NULL) { #define SBUF_SIZE 512 #define ELLIPSES_PREFIX "[...]" static char static_buf[SBUF_SIZE]; int truncated; size_t len; char *p; len = right_justify (static_buf, SBUF_SIZE, filename, filename_len + 1, &p, &truncated); right_justify (static_buf, len, dir_name, dir_len, &p, &truncated); if (truncated) { memcpy (static_buf, ELLIPSES_PREFIX, sizeof (ELLIPSES_PREFIX) - 1); } return p; } } /* Copy directory part, including trailing slash, and then append the filename part, including a trailing zero byte. */ memcpy (mempcpy (buf, dir_name, dir_len), filename, filename_len + 1); assert (strlen (buf) + 1 == n_bytes_needed); return buf; } void fspec_init_file (struct File_spec *fs, const char *filename) { fs->filename = (char *) filename; fs->have_full_mode = 0; fs->have_filetype_mode = 0; } static inline void fspec_init_dp (struct File_spec *fs, struct dirent *dp) { fs->filename = dp->d_name; fs->have_full_mode = 0; fs->have_filetype_mode = 0; fs->inum = D_INO (dp); #if D_TYPE_IN_DIRENT && defined (DT_UNKNOWN) && defined (DTTOIF) if (dp->d_type != DT_UNKNOWN) { fs->have_filetype_mode = 1; fs->mode = DTTOIF (dp->d_type); } #endif } static inline int fspec_get_full_mode (struct File_spec *fs, mode_t *full_mode) { struct stat stat_buf; if (fs->have_full_mode) { *full_mode = fs->mode; return 0; } if (lstat (fs->filename, &stat_buf)) return 1; fs->have_full_mode = 1; fs->have_filetype_mode = 1; fs->mode = stat_buf.st_mode; fs->inum = stat_buf.st_ino; *full_mode = stat_buf.st_mode; return 0; } static inline int fspec_get_filetype_mode (struct File_spec *fs, mode_t *filetype_mode) { int fail; if (fs->have_filetype_mode) { *filetype_mode = fs->mode; fail = 0; } else { fail = fspec_get_full_mode (fs, filetype_mode); } return fail; } static inline mode_t fspec_filetype_mode (const struct File_spec *fs) { assert (fs->have_filetype_mode); return fs->mode; } /* Recursively remove all of the entries in the current directory. Return an indication of the success of the operation. */ enum RM_status remove_cwd_entries (const struct rm_options *x) { /* NOTE: this is static. */ static DIR *dirp = NULL; /* NULL or a malloc'd and initialized hash table of entries in the current directory that have been processed but not removed -- due either to an error or to an interactive `no' response. */ struct HT *ht = NULL; /* FIXME: describe */ static struct obstack entry_name_pool; static int first_call = 1; enum RM_status status = RM_OK; if (first_call) { first_call = 0; obstack_init (&entry_name_pool); } if (dirp) { if (CLOSEDIR (dirp)) { /* FIXME-someday: but this is actually the previously opened dir. */ error (0, errno, "%s", full_filename (".")); status = RM_ERROR; } dirp = NULL; } do { /* FIXME: why do this? */ errno = 0; dirp = opendir ("."); if (dirp == NULL) { if (errno != ENOENT || !x->ignore_missing_files) { error (0, errno, "%s", full_filename (".")); status = RM_ERROR; } break; } while (1) { char *entry_name; struct File_spec fs; enum RM_status tmp_status; struct dirent *dp; /* FILE should be skipped if it is `.' or `..', or if it is in the table, HT, of entries we've already processed. */ #define SKIPPABLE(Ht, File) (DOT_OR_DOTDOT(File) \ || (Ht && hash_query_in_table (Ht, File))) /* FIXME: use readdir_r directly into an obstack to avoid the obstack_copy0 below -- Suggestion from Uli. Be careful -- there are different prototypes on e.g. Solaris. Do something like this: #define NAME_MAX_FOR(Parent_dir) pathconf ((Parent_dir), _PC_NAME_MAX); dp = obstack_alloc (sizeof (struct dirent) + NAME_MAX_FOR (".") + 1); fail = xreaddir (dirp, dp); where xreaddir is ... But what about systems like the hurd where NAME_MAX is supposed to be effectively unlimited. We don't want to have to allocate a huge buffer to accommodate maximum possible entry name. */ dp = readdir (dirp); #if ! HAVE_WORKING_READDIR if (dp == NULL) { /* Since we have probably modified the directory since it was opened, readdir returning NULL does not necessarily mean we have read the last entry. Rewind it and check again. This happens on SunOS4.1.4 with 254 or more files in a directory. */ rewinddir (dirp); while ((dp = readdir (dirp)) && SKIPPABLE (ht, dp->d_name)) { /* empty */ } } #endif if (dp == NULL) break; if (SKIPPABLE (ht, dp->d_name)) continue; fspec_init_dp (&fs, dp); /* Save a copy of the name of this entry, in case we have to add it to the set of unremoved entries below. */ entry_name = obstack_copy0 (&entry_name_pool, dp->d_name, NLENGTH (dp)); /* CAUTION: after this call to rm, DP may not be valid -- it may have been freed due to a close in a recursive call (through rm and remove_dir) to this function. */ tmp_status = rm (&fs, 0, x); /* Update status. */ if (tmp_status > status) status = tmp_status; assert (VALID_STATUS (status)); /* If this entry was not removed (due either to an error or to an interactive `no' response), record it in the hash table so we don't consider it again if we reopen this directory later. */ if (status != RM_OK) { int fail; if (ht == NULL) { ht = hash_initialize (HT_INITIAL_CAPACITY, NULL, hash_pjw, hash_compare_strings); if (ht == NULL) error (1, 0, _("virtual memory exhausted")); } HASH_INSERT_NEW_ITEM (ht, entry_name, &fail); if (fail) error (1, 0, _("virtual memory exhausted")); } else { /* This entry was not saved in the hash table. Free it. */ obstack_free (&entry_name_pool, entry_name); } if (dirp == NULL) break; } } while (dirp == NULL); if (CLOSEDIR (dirp)) { error (0, errno, "%s", full_filename (".")); status = 1; } dirp = NULL; if (ht) { hash_free (ht); } if (obstack_object_size (&entry_name_pool) > 0) obstack_free (&entry_name_pool, obstack_base (&entry_name_pool)); return status; } /* Query the user if appropriate, and if ok try to remove the file or directory specified by FS. Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not. */ static enum RM_status remove_file (struct File_spec *fs, const struct rm_options *x) { int asked = 0; char *pathname = fs->filename; if (!x->ignore_missing_files && (x->interactive || x->stdin_tty) && euidaccess (pathname, W_OK)) { if (!S_ISLNK (fspec_filetype_mode (fs))) { fprintf (stderr, (S_ISDIR (fspec_filetype_mode (fs)) ? _("%s: remove write-protected directory `%s'? ") : _("%s: remove write-protected file `%s'? ")), program_name, full_filename (pathname)); if (!yesno ()) return RM_USER_DECLINED; asked = 1; } } if (!asked && x->interactive) { /* FIXME: use a variant of error (instead of fprintf) that doesn't append a newline. Then we won't have to declare program_name in this file. */ fprintf (stderr, (S_ISDIR (fspec_filetype_mode (fs)) ? _("%s: remove directory `%s'? ") : _("%s: remove `%s'? ")), program_name, full_filename (pathname)); if (!yesno ()) return RM_USER_DECLINED; } if (x->verbose) printf (_("removing non-directory %s\n"), full_filename (pathname)); if (unlink (pathname) && (errno != ENOENT || !x->ignore_missing_files)) { error (0, errno, _("cannot unlink `%s'"), full_filename (pathname)); return RM_ERROR; } return RM_OK; } /* If not in recursive mode, print an error message and return RM_ERROR. Otherwise, query the user if appropriate, then try to recursively remove the directory specified by FS. Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not. FIXME: describe need_save_cwd parameter. */ static enum RM_status remove_dir (struct File_spec *fs, int need_save_cwd, const struct rm_options *x) { enum RM_status status; struct saved_cwd cwd; char *dir_name = fs->filename; const char *fmt = NULL; if (!x->recursive) { error (0, 0, _("%s: is a directory"), full_filename (dir_name)); return RM_ERROR; } if (!x->ignore_missing_files && (x->interactive || x->stdin_tty) && euidaccess (dir_name, W_OK)) { fmt = _("%s: directory `%s' is write protected; descend into it anyway? "); } else if (x->interactive) { fmt = _("%s: descend into directory `%s'? "); } if (fmt) { fprintf (stderr, fmt, program_name, full_filename (dir_name)); if (!yesno ()) return RM_USER_DECLINED; } if (x->verbose) printf (_("removing all entries of directory %s\n"), full_filename (dir_name)); /* Save cwd if needed. */ if (need_save_cwd && save_cwd (&cwd)) return RM_ERROR; /* Make target directory the current one. */ if (chdir (dir_name) < 0) { error (0, errno, _("cannot change to directory %s"), full_filename (dir_name)); if (need_save_cwd) free_cwd (&cwd); return RM_ERROR; } push_dir (dir_name); /* Save a copy of dir_name. Otherwise, remove_cwd_entries may clobber it because it is just a pointer to the dir entry's d_name field, and remove_cwd_entries may close the directory. */ ASSIGN_STRDUPA (dir_name, dir_name); status = remove_cwd_entries (x); pop_dir (); /* Restore cwd. */ if (need_save_cwd) { if (restore_cwd (&cwd, NULL, NULL)) { free_cwd (&cwd); return RM_ERROR; } free_cwd (&cwd); } else if (chdir ("..") < 0) { error (0, errno, _("cannot change back to directory %s via `..'"), full_filename (dir_name)); return RM_ERROR; } if (x->interactive) { error (0, 0, _("remove directory `%s'%s? "), full_filename (dir_name), (status != RM_OK ? _(" (might be nonempty)") : "")); if (!yesno ()) { return RM_USER_DECLINED; } } if (x->verbose) printf (_("removing the directory itself: %s\n"), full_filename (dir_name)); if (rmdir (dir_name) && (errno != ENOENT || !x->ignore_missing_files)) { error (0, errno, _("cannot remove directory `%s'"), full_filename (dir_name)); return RM_ERROR; } return RM_OK; } /* Remove the file or directory specified by FS after checking appropriate things. Return RM_OK if it is removed, and RM_ERROR or RM_USER_DECLINED if not. If USER_SPECIFIED_NAME is non-zero, then the name part of FS may be `.', `..', or may contain slashes. Otherwise, it must be a simple file name (and hence must specify a file in the current directory). */ enum RM_status rm (struct File_spec *fs, int user_specified_name, const struct rm_options *x) { mode_t filetype_mode; if (user_specified_name) { char *base = base_name (fs->filename); if (DOT_OR_DOTDOT (base)) { error (0, 0, _("cannot remove `.' or `..'")); return RM_ERROR; } } if (fspec_get_filetype_mode (fs, &filetype_mode)) { if (x->ignore_missing_files && errno == ENOENT) return RM_OK; error (0, errno, _("cannot remove `%s'"), full_filename (fs->filename)); return RM_ERROR; } #ifdef ENABLE_CYCLE_CHECK if (S_ISDIR (filetype_mode)) { int fail; struct active_dir_ent *old_ent; /* Insert this directory in the active_dir_map. If there is already a directory in the map with the same inum, then there's *probably* a directory cycle. This test can get a false positive if two directories have the same inode number but different device numbers and one directory contains the other. But since people don't often try to delete hierarchies containing mount points, and when they do, duplicate inode numbers are not that likely, this isn't worth detecting. */ old_ent = hash_insert_if_absent (active_dir_map, make_active_dir_ent (fs->inum, current_depth ()), &fail); if (fail) error (1, 0, _("virtual memory exhausted")); if (old_ent) { error (0, 0, _("\ WARNING: Circular directory structure.\n\ This almost certainly means that you have a corrupted file system.\n\ NOTIFY YOUR SYSTEM MANAGER.\n\ The following two directories have the same inode number:\n")); /* FIXME: test this!! */ print_nth_dir (stderr, current_depth ()); fputc ('\n', stderr); print_nth_dir (stderr, old_ent->depth); fputc ('\n', stderr); fflush (stderr); free (old_ent); if (x->interactive) { error (0, 0, _("continue? ")); if (yesno ()) return RM_ERROR; } exit (1); } } #endif if (!S_ISDIR (filetype_mode) || x->unlink_dirs) { return remove_file (fs, x); } else { int need_save_cwd = user_specified_name; enum RM_status status; if (need_save_cwd) need_save_cwd = (strchr (fs->filename, '/') != NULL); status = remove_dir (fs, need_save_cwd, x); #ifdef ENABLE_CYCLE_CHECK { struct active_dir_ent tmp; struct active_dir_ent *old_ent; /* Remove this directory from the active_dir_map. */ tmp.inum = fs->inum; old_ent = hash_delete_if_present (active_dir_map, &tmp); assert (old_ent != NULL); free (old_ent); } #endif return status; } } void remove_init (void) { /* Initialize dir-stack obstacks. */ obstack_init (&dir_stack); obstack_init (&len_stack); #ifdef ENABLE_CYCLE_CHECK active_dir_map = hash_initialize (ACTIVE_DIR_INITIAL_CAPACITY, free, hash_active_dir_ent, hash_compare_active_dir_ents); #endif } void remove_fini (void) { #ifdef ENABLE_CYCLE_CHECK hash_free (active_dir_map); #endif obstack_free (&dir_stack, NULL); obstack_free (&len_stack, NULL); }