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* Copyright (c) 2003-2007 Tim Kientzle
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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* This is a new directory-walking system that addresses a number
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* of problems I've had with fts(3). In particular, it has no
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* pathname-length limits (other than the size of 'int'), handles
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* deep logical traversals, uses considerably less memory, and has
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* an opaque interface (easier to modify in the future).
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* Internally, it keeps a single list of "tree_entry" items that
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* represent filesystem objects that require further attention.
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* Non-directories are not kept in memory: they are pulled from
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* readdir(), returned to the client, then freed as soon as possible.
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* Any directory entry to be traversed gets pushed onto the stack.
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* There is surprisingly little information that needs to be kept for
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* each item on the stack. Just the name, depth (represented here as the
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* string length of the parent directory's pathname), and some markers
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* indicating how to get back to the parent (via chdir("..") for a
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* regular dir or via fchdir(2) for a symlink).
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#include "tree_config.h"
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__FBSDID("$FreeBSD$");
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#ifdef HAVE_SYS_STAT_H
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* 3) Arbitrary logical traversals by closing/reopening intermediate fds.
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struct tree_entry *next;
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struct tree_entry *parent;
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size_t dirname_length;
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/* Definitions for tree_entry.flags bitmap. */
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#define isDir 1 /* This entry is a regular directory. */
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#define isDirLink 2 /* This entry is a symbolic link to a directory. */
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#define needsPreVisit 4 /* This entry needs to be previsited. */
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#define needsPostVisit 8 /* This entry needs to be postvisited. */
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* Local data for this package.
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struct tree_entry *stack;
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struct tree_entry *current;
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int tree_errno; /* Error code from last failed operation. */
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const char *basename;
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size_t dirname_length;
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/* Definitions for tree.flags bitmap. */
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#define needsReturn 8 /* Marks first entry as not having been returned yet. */
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#define hasStat 16 /* The st entry is set. */
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#define hasLstat 32 /* The lst entry is set. */
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#ifdef HAVE_DIRENT_D_NAMLEN
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/* BSD extension; avoids need for a strlen() call. */
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#define D_NAMELEN(dp) (dp)->d_namlen
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#define D_NAMELEN(dp) (strlen((dp)->d_name))
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tree_dump(struct tree *t, FILE *out)
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struct tree_entry *te;
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fprintf(out, "\tdepth: %d\n", t->depth);
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fprintf(out, "\tbuff: %s\n", t->buff);
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fprintf(out, "\tpwd: "); fflush(stdout); system("pwd");
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fprintf(out, "\taccess: %s\n", t->basename);
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fprintf(out, "\tstack:\n");
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for (te = t->stack; te != NULL; te = te->next) {
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fprintf(out, "\t\tte->name: %s%s%s\n", te->name,
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te->flags & needsPreVisit ? "" : " *",
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t->current == te ? " (current)" : "");
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* Add a directory path to the current stack.
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tree_push(struct tree *t, const char *path)
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struct tree_entry *te;
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te = malloc(sizeof(*te));
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memset(te, 0, sizeof(*te));
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te->name = strdup(path);
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te->flags = needsPreVisit | needsPostVisit;
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te->dirname_length = t->dirname_length;
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* Append a name to the current path.
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tree_append(struct tree *t, const char *name, size_t name_length)
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t->buff[t->dirname_length] = '\0';
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/* Strip trailing '/' from name, unless entire name is "/". */
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while (name_length > 1 && name[name_length - 1] == '/')
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/* Resize pathname buffer as needed. */
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while (name_length + 1 + t->dirname_length >= t->buff_length) {
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if (t->buff_length < 1024)
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t->buff_length = 1024;
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t->buff = realloc(t->buff, t->buff_length);
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p = t->buff + t->dirname_length;
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t->path_length = t->dirname_length + name_length;
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/* Add a separating '/' if it's needed. */
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if (t->dirname_length > 0 && p[-1] != '/') {
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strncpy(p, name, name_length);
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p[name_length] = '\0';
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* Open a directory tree for traversal.
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tree_open(const char *path)
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t = malloc(sizeof(*t));
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memset(t, 0, sizeof(*t));
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tree_append(t, path, strlen(path));
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t->initialDirFd = open(".", O_RDONLY);
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* During most of the traversal, items are set up and then
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* returned immediately from tree_next(). That doesn't work
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* for the very first entry, so we set a flag for this special
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t->flags = needsReturn;
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* We've finished a directory; ascend back to the parent.
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tree_ascend(struct tree *t)
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struct tree_entry *te;
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if (te->flags & isDirLink) {
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* Pop the working stack.
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tree_pop(struct tree *t)
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struct tree_entry *te;
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t->buff[t->dirname_length] = '\0';
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if (t->stack == t->current && t->current != NULL)
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t->current = t->current->parent;
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t->dirname_length = te->dirname_length;
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t->basename = t->buff + t->dirname_length;
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/* Special case: starting dir doesn't skip leading '/'. */
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if (t->dirname_length > 0)
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* Get the next item in the tree traversal.
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tree_next(struct tree *t)
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struct dirent *de = NULL;
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/* Handle the startup case by returning the initial entry. */
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if (t->flags & needsReturn) {
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t->flags &= ~needsReturn;
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return (t->visit_type = TREE_REGULAR);
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while (t->stack != NULL) {
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/* If there's an open dir, get the next entry from there. */
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while (t->d != NULL) {
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} else if (de->d_name[0] == '.'
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&& de->d_name[1] == '\0') {
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} else if (de->d_name[0] == '.'
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&& de->d_name[1] == '.'
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&& de->d_name[2] == '\0') {
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* Append the path to the current path
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tree_append(t, de->d_name, D_NAMELEN(de));
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t->flags &= ~hasLstat;
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t->flags &= ~hasStat;
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return (t->visit_type = TREE_REGULAR);
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/* If the current dir needs to be visited, set it up. */
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if (t->stack->flags & needsPreVisit) {
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t->current = t->stack;
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tree_append(t, t->stack->name, strlen(t->stack->name));
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t->stack->flags &= ~needsPreVisit;
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/* If it is a link, set up fd for the ascent. */
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if (t->stack->flags & isDirLink) {
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t->stack->fd = open(".", O_RDONLY);
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if (t->openCount > t->maxOpenCount)
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t->maxOpenCount = t->openCount;
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t->dirname_length = t->path_length;
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if (chdir(t->stack->name) != 0) {
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/* chdir() failed; return error */
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t->tree_errno = errno;
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return (t->visit_type = TREE_ERROR_DIR);
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tree_ascend(t); /* Undo "chdir" */
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t->tree_errno = errno;
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return (t->visit_type = TREE_ERROR_DIR);
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t->flags &= ~hasLstat;
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t->flags &= ~hasStat;
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return (t->visit_type = TREE_POSTDESCENT);
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/* We've done everything necessary for the top stack entry. */
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if (t->stack->flags & needsPostVisit) {
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t->flags &= ~hasLstat;
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t->flags &= ~hasStat;
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return (t->visit_type = TREE_POSTASCENT);
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return (t->visit_type = 0);
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tree_errno(struct tree *t)
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return (t->tree_errno);
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* Called by the client to mark the directory just returned from
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* tree_next() as needing to be visited.
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tree_descend(struct tree *t)
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if (t->visit_type != TREE_REGULAR)
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if (tree_current_is_physical_dir(t)) {
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tree_push(t, t->basename);
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t->stack->flags |= isDir;
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} else if (tree_current_is_dir(t)) {
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tree_push(t, t->basename);
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t->stack->flags |= isDirLink;
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* Get the stat() data for the entry just returned from tree_next().
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tree_current_stat(struct tree *t)
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if (!(t->flags & hasStat)) {
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if (stat(t->basename, &t->st) != 0)
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* Get the lstat() data for the entry just returned from tree_next().
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tree_current_lstat(struct tree *t)
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if (!(t->flags & hasLstat)) {
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if (lstat(t->basename, &t->lst) != 0)
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t->flags |= hasLstat;
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* Test whether current entry is a dir or link to a dir.
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tree_current_is_dir(struct tree *t)
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const struct stat *st;
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* If we already have lstat() info, then try some
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* cheap tests to determine if this is a dir.
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if (t->flags & hasLstat) {
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/* If lstat() says it's a dir, it must be a dir. */
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if (S_ISDIR(tree_current_lstat(t)->st_mode))
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/* Not a dir; might be a link to a dir. */
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/* If it's not a link, then it's not a link to a dir. */
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if (!S_ISLNK(tree_current_lstat(t)->st_mode))
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* It's a link, but we don't know what it's a link to,
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* so we'll have to use stat().
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st = tree_current_stat(t);
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/* If we can't stat it, it's not a dir. */
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/* Use the definitive test. Hopefully this is cached. */
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return (S_ISDIR(st->st_mode));
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* Test whether current entry is a physical directory. Usually, we
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* already have at least one of stat() or lstat() in memory, so we
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* use tricks to try to avoid an extra trip to the disk.
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tree_current_is_physical_dir(struct tree *t)
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const struct stat *st;
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* If stat() says it isn't a dir, then it's not a dir.
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* If stat() data is cached, this check is free, so do it first.
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if ((t->flags & hasStat)
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&& (!S_ISDIR(tree_current_stat(t)->st_mode)))
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* Either stat() said it was a dir (in which case, we have
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* to determine whether it's really a link to a dir) or
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* stat() info wasn't available. So we use lstat(), which
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* hopefully is already cached.
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st = tree_current_lstat(t);
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/* If we can't stat it, it's not a dir. */
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/* Use the definitive test. Hopefully this is cached. */
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return (S_ISDIR(st->st_mode));
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* Test whether current entry is a symbolic link.
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tree_current_is_physical_link(struct tree *t)
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const struct stat *st = tree_current_lstat(t);
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return (S_ISLNK(st->st_mode));
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* Return the access path for the entry just returned from tree_next().
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tree_current_access_path(struct tree *t)
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return (t->basename);
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* Return the full path for the entry just returned from tree_next().
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tree_current_path(struct tree *t)
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* Return the length of the path for the entry just returned from tree_next().
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tree_current_pathlen(struct tree *t)
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return (t->path_length);
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* Return the nesting depth of the entry just returned from tree_next().
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tree_current_depth(struct tree *t)
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* Terminate the traversal and release any resources.
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tree_close(struct tree *t)
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/* Release anything remaining in the stack. */
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while (t->stack != NULL)
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/* chdir() back to where we started. */
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if (t->initialDirFd >= 0) {
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fchdir(t->initialDirFd);
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close(t->initialDirFd);
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t->initialDirFd = -1;
added
removed
src/libarchive/contrib/shar/tree.c
