424 lines
11 KiB
C
424 lines
11 KiB
C
|
/*-
|
||
|
|
* Copyright (c) 2003-2004 Tim Kientzle
|
||
|
|
* 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
|
||
|
|
* in this position and unchanged.
|
||
|
|
* 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.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*-
|
||
|
|
* There is a single list of "tree_entry" items that represent
|
||
|
|
* filesystem objects that require further attention. Non-directories
|
||
|
|
* are not kept in memory: they are pulled from readdir(), returned to
|
||
|
|
* the client, then freed as soon as possible. Any directory entry to
|
||
|
|
* be traversed gets pushed onto the stack.
|
||
|
|
*
|
||
|
|
* There is surprisingly little information that needs to be kept for
|
||
|
|
* each item on the stack. Just the name, depth (represented here as the
|
||
|
|
* string length of the parent directory's pathname), and some markers
|
||
|
|
* indicating how to get back to the parent (via chdir("..") for a
|
||
|
|
* regular dir or via fchdir(2) for a symlink).
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <sys/stat.h>
|
||
|
|
#include <dirent.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
|
||
|
|
#include "tree.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* TODO:
|
||
|
|
* 1) Loop checking.
|
||
|
|
* 3) Arbitrary logical traversals by closing/reopening intermediate fds.
|
||
|
|
*/
|
||
|
|
|
||
|
|
struct tree_entry {
|
||
|
|
struct tree_entry *next;
|
||
|
|
char *name;
|
||
|
|
size_t dirname_length;
|
||
|
|
int fd;
|
||
|
|
int flags;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* Definitions for tree_entry.flags bitmap. */
|
||
|
|
#define isDir 1 /* This entry is a regular directory. */
|
||
|
|
#define isDirLink 2 /* This entry is a symbolic link to a directory. */
|
||
|
|
#define needsTraversal 4 /* This entry hasn't yet been traversed. */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Local data for this package.
|
||
|
|
*/
|
||
|
|
struct tree {
|
||
|
|
struct tree_entry *stack;
|
||
|
|
DIR *d;
|
||
|
|
int initialDirFd;
|
||
|
|
int flags;
|
||
|
|
|
||
|
|
char *buff;
|
||
|
|
char *basename;
|
||
|
|
size_t buff_length;
|
||
|
|
size_t path_length;
|
||
|
|
size_t dirname_length;
|
||
|
|
|
||
|
|
int depth;
|
||
|
|
int openCount;
|
||
|
|
int maxOpenCount;
|
||
|
|
|
||
|
|
struct stat lst;
|
||
|
|
struct stat st;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* Definitions for tree.flags bitmap. */
|
||
|
|
#define needsReturn 8 /* Marks first entry as not having been returned yet. */
|
||
|
|
#define hasStat 16 /* The st entry is set. */
|
||
|
|
#define hasLstat 32 /* The lst entry is set. */
|
||
|
|
|
||
|
|
|
||
|
|
#define HAVE_DIRENT_D_NAMLEN 1
|
||
|
|
#ifdef HAVE_DIRENT_D_NAMLEN
|
||
|
|
/* BSD extension; avoids need for a strlen() call. */
|
||
|
|
#define D_NAMELEN(dp) (dp)->d_namlen
|
||
|
|
#else
|
||
|
|
#define D_NAMELEN(dp) (strlen((dp)->d_name))
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#if 0
|
||
|
|
static void
|
||
|
|
dumpStack(struct tree *t)
|
||
|
|
{
|
||
|
|
struct tree_entry *te;
|
||
|
|
|
||
|
|
printf("\tbuff: %s\n", t->buff);
|
||
|
|
printf("\tpwd: "); fflush(stdout); system("pwd");
|
||
|
|
printf("\tstack:\n");
|
||
|
|
for (te = t->stack; te != NULL; te = te->next) {
|
||
|
|
printf("\t\tte->name: %s %s\n", te->name, te->flags & needsTraversal ? "" : "*");
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Add a directory path to the current stack.
|
||
|
|
*/
|
||
|
|
static void
|
||
|
|
tree_add(struct tree *t, const char *path)
|
||
|
|
{
|
||
|
|
struct tree_entry *te;
|
||
|
|
|
||
|
|
te = malloc(sizeof(*te));
|
||
|
|
memset(te, 0, sizeof(*te));
|
||
|
|
te->next = t->stack;
|
||
|
|
t->stack = te;
|
||
|
|
te->fd = -1;
|
||
|
|
te->name = strdup(path);
|
||
|
|
te->flags = needsTraversal;
|
||
|
|
te->dirname_length = t->dirname_length;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Append a name to the current path.
|
||
|
|
*/
|
||
|
|
static void
|
||
|
|
tree_append(struct tree *t, const char *name, size_t name_length)
|
||
|
|
{
|
||
|
|
if (t->buff != NULL)
|
||
|
|
t->buff[t->dirname_length] = '\0';
|
||
|
|
|
||
|
|
/* Resize pathname buffer as needed. */
|
||
|
|
while (name_length + 1 + t->dirname_length >= t->buff_length) {
|
||
|
|
t->buff_length *= 2;
|
||
|
|
if (t->buff_length < 1024)
|
||
|
|
t->buff_length = 1024;
|
||
|
|
t->buff = realloc(t->buff, t->buff_length);
|
||
|
|
}
|
||
|
|
t->basename = t->buff + t->dirname_length;
|
||
|
|
t->path_length = t->dirname_length + name_length;
|
||
|
|
if (t->dirname_length > 0) {
|
||
|
|
*t->basename++ = '/';
|
||
|
|
t->path_length ++;
|
||
|
|
}
|
||
|
|
strcpy(t->basename, name);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Open a directory tree for traversal.
|
||
|
|
*/
|
||
|
|
struct tree *
|
||
|
|
tree_open(const char *path)
|
||
|
|
{
|
||
|
|
struct tree *t;
|
||
|
|
|
||
|
|
t = malloc(sizeof(*t));
|
||
|
|
memset(t, 0, sizeof(*t));
|
||
|
|
tree_append(t, path, strlen(path));
|
||
|
|
t->initialDirFd = open(".", O_RDONLY);
|
||
|
|
/*
|
||
|
|
* During most of the traversal, items are set up and then
|
||
|
|
* returned immediately from tree_next(). That doesn't work
|
||
|
|
* for the very first entry, so we set a flag for this special
|
||
|
|
* case.
|
||
|
|
*/
|
||
|
|
t->flags = needsReturn;
|
||
|
|
return (t);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* We've finished a directory; ascend back to the parent.
|
||
|
|
*/
|
||
|
|
static void
|
||
|
|
tree_ascend(struct tree *t)
|
||
|
|
{
|
||
|
|
struct tree_entry *te;
|
||
|
|
|
||
|
|
te = t->stack;
|
||
|
|
t->depth--;
|
||
|
|
if (te->flags & isDirLink) {
|
||
|
|
fchdir(te->fd);
|
||
|
|
close(te->fd);
|
||
|
|
t->openCount--;
|
||
|
|
} else {
|
||
|
|
chdir("..");
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Pop the working stack.
|
||
|
|
*/
|
||
|
|
static void
|
||
|
|
tree_pop(struct tree *t)
|
||
|
|
{
|
||
|
|
struct tree_entry *te;
|
||
|
|
|
||
|
|
te = t->stack;
|
||
|
|
t->stack = te->next;
|
||
|
|
t->dirname_length = te->dirname_length;
|
||
|
|
free(te->name);
|
||
|
|
free(te);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Get the next item in the tree traversal.
|
||
|
|
*/
|
||
|
|
int
|
||
|
|
tree_next(struct tree *t)
|
||
|
|
{
|
||
|
|
struct dirent *de = NULL;
|
||
|
|
|
||
|
|
/* Handle the startup case by returning the initial entry. */
|
||
|
|
if (t->flags & needsReturn) {
|
||
|
|
t->flags &= ~needsReturn;
|
||
|
|
return (1);
|
||
|
|
}
|
||
|
|
|
||
|
|
while (t->stack != NULL) {
|
||
|
|
/* If there's an open dir, get the next entry from there. */
|
||
|
|
while (t->d != NULL) {
|
||
|
|
de = readdir(t->d);
|
||
|
|
if (de == NULL) {
|
||
|
|
closedir(t->d);
|
||
|
|
t->d = NULL;
|
||
|
|
} else if (de->d_name[0] == '.'
|
||
|
|
&& de->d_name[1] == '\0') {
|
||
|
|
/* Skip '.' */
|
||
|
|
} else if (de->d_name[0] == '.'
|
||
|
|
&& de->d_name[1] == '.'
|
||
|
|
&& de->d_name[2] == '\0') {
|
||
|
|
/* Skip '..' */
|
||
|
|
} else {
|
||
|
|
/*
|
||
|
|
* Append the path to the current path
|
||
|
|
* and return it.
|
||
|
|
*/
|
||
|
|
tree_append(t, de->d_name, D_NAMELEN(de));
|
||
|
|
t->flags &= ~hasLstat;
|
||
|
|
t->flags &= ~hasStat;
|
||
|
|
return (1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/* If the current dir needs to be traversed, set it up. */
|
||
|
|
if (t->stack->flags & needsTraversal) {
|
||
|
|
tree_append(t, t->stack->name, strlen(t->stack->name));
|
||
|
|
t->stack->flags &= ~needsTraversal;
|
||
|
|
/* If it is a link, set up fd for the ascent. */
|
||
|
|
if (t->stack->flags & isDirLink) {
|
||
|
|
t->stack->fd = open(".", O_RDONLY);
|
||
|
|
t->openCount++;
|
||
|
|
if (t->openCount > t->maxOpenCount)
|
||
|
|
t->maxOpenCount = t->openCount;
|
||
|
|
}
|
||
|
|
if (chdir(t->stack->name) == 0) {
|
||
|
|
t->depth++;
|
||
|
|
t->dirname_length = t->path_length;
|
||
|
|
t->d = opendir(".");
|
||
|
|
} else
|
||
|
|
tree_pop(t);
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* We've done everything necessary for the top stack entry. */
|
||
|
|
tree_ascend(t);
|
||
|
|
tree_pop(t);
|
||
|
|
}
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Called by the client to mark the directory just returned from
|
||
|
|
* tree_next() as needing to be visited.
|
||
|
|
*/
|
||
|
|
void
|
||
|
|
tree_descend(struct tree *t)
|
||
|
|
{
|
||
|
|
const struct stat *s = tree_current_lstat(t);
|
||
|
|
|
||
|
|
if (S_ISDIR(s->st_mode)) {
|
||
|
|
tree_add(t, t->basename);
|
||
|
|
t->stack->flags |= isDir;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (S_ISLNK(s->st_mode) && S_ISDIR(tree_current_stat(t)->st_mode)) {
|
||
|
|
tree_add(t, t->basename);
|
||
|
|
t->stack->flags |= isDirLink;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Get the stat() data for the entry just returned from tree_next().
|
||
|
|
*/
|
||
|
|
const struct stat *
|
||
|
|
tree_current_stat(struct tree *t)
|
||
|
|
{
|
||
|
|
if (!(t->flags & hasStat)) {
|
||
|
|
stat(t->basename, &t->st);
|
||
|
|
t->flags |= hasStat;
|
||
|
|
}
|
||
|
|
return (&t->st);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Get the lstat() data for the entry just returned from tree_next().
|
||
|
|
*/
|
||
|
|
const struct stat *
|
||
|
|
tree_current_lstat(struct tree *t)
|
||
|
|
{
|
||
|
|
if (!(t->flags & hasLstat)) {
|
||
|
|
lstat(t->basename, &t->lst);
|
||
|
|
t->flags |= hasLstat;
|
||
|
|
}
|
||
|
|
return (&t->lst);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Return the access path for the entry just returned from tree_next().
|
||
|
|
*/
|
||
|
|
const char *
|
||
|
|
tree_current_access_path(struct tree *t)
|
||
|
|
{
|
||
|
|
return (t->basename);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Return the full path for the entry just returned from tree_next().
|
||
|
|
*/
|
||
|
|
const char *
|
||
|
|
tree_current_path(struct tree *t)
|
||
|
|
{
|
||
|
|
return (t->buff);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Return the length of the path for the entry just returned from tree_next().
|
||
|
|
*/
|
||
|
|
size_t
|
||
|
|
tree_current_pathlen(struct tree *t)
|
||
|
|
{
|
||
|
|
return (t->path_length);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Return the nesting depth of the entry just returned from tree_next().
|
||
|
|
*/
|
||
|
|
int
|
||
|
|
tree_current_depth(struct tree *t)
|
||
|
|
{
|
||
|
|
return (t->depth);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Terminate the traversal and release any resources.
|
||
|
|
*/
|
||
|
|
void
|
||
|
|
tree_close(struct tree *t)
|
||
|
|
{
|
||
|
|
/* Release anything remaining in the stack. */
|
||
|
|
while (t->stack != NULL)
|
||
|
|
tree_pop(t);
|
||
|
|
if (t->buff)
|
||
|
|
free(t->buff);
|
||
|
|
/* chdir() back to where we started. */
|
||
|
|
if (t->initialDirFd >= 0) {
|
||
|
|
fchdir(t->initialDirFd);
|
||
|
|
close(t->initialDirFd);
|
||
|
|
t->initialDirFd = -1;
|
||
|
|
}
|
||
|
|
free(t);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
#if 0
|
||
|
|
/* Main function for testing. */
|
||
|
|
#include <stdio.h>
|
||
|
|
|
||
|
|
int main(int argc, char **argv)
|
||
|
|
{
|
||
|
|
size_t max_path_len = 0;
|
||
|
|
int max_depth = 0;
|
||
|
|
|
||
|
|
system("pwd");
|
||
|
|
while (*++argv) {
|
||
|
|
struct tree *t = tree_open(*argv);
|
||
|
|
while (tree_next(t)) {
|
||
|
|
size_t path_len = tree_current_pathlen(t);
|
||
|
|
int depth = tree_current_depth(t);
|
||
|
|
if (path_len > max_path_len)
|
||
|
|
max_path_len = path_len;
|
||
|
|
if (depth > max_depth)
|
||
|
|
max_depth = depth;
|
||
|
|
printf("%s\n", tree_current_path(t));
|
||
|
|
if (S_ISDIR(tree_current_lstat(t)->st_mode))
|
||
|
|
tree_descend(t); /* Descend into every dir. */
|
||
|
|
}
|
||
|
|
tree_close(t);
|
||
|
|
printf("Max path length: %d\n", max_path_len);
|
||
|
|
printf("Max depth: %d\n", max_depth);
|
||
|
|
printf("Final open count: %d\n", t->openCount);
|
||
|
|
printf("Max open count: %d\n", t->maxOpenCount);
|
||
|
|
fflush(stdout);
|
||
|
|
system("pwd");
|
||
|
|
}
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
#endif
|