* Copyright (c) 1990 The Regents of the University of California.
* %sccs.include.redist.c%
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid
[] = "@(#)fts.c 5.16 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
static FTSENT
*fts_alloc(), *fts_build(), *fts_sort();
static u_short
fts_stat();
#define ISSET(opt) (sp->fts_options & opt)
#define SET(opt) (sp->fts_options |= opt)
#define CHDIR(sp, path) (!ISSET(FTS_NOCHDIR) && chdir(path))
#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
#define BCHILD 1 /* from fts_children */
#define BREAD 2 /* from fts_read */
fts_open(argv
, options
, compar
)
register FTSENT
*p
, *root
;
register int nitems
, maxlen
;
/* Allocate/initialize the stream */
if (!(sp
= (FTS
*)malloc((u_int
)sizeof(FTS
))))
sp
->fts_options
= options
;
/* Logical walks turn on NOCHDIR; symbolic links are too hard. */
/* Allocate/initialize root's parent. */
if (!(parent
= fts_alloc(sp
, "", 0)))
parent
->fts_level
= FTS_ROOTPARENTLEVEL
;
/* Allocate/initialize root(s). */
for (root
= NULL
, nitems
= 0; *argv
; ++argv
, ++nitems
) {
if (!(len
= strlen(*argv
))) {
p
= fts_alloc(sp
, *argv
, len
);
* If comparison routine supplied, traverse in sorted
* order; otherwise traverse in the order specified.
p
->fts_accpath
= p
->fts_name
;
if (!(options
& FTS_NOSTAT
))
p
->fts_info
= fts_stat(sp
, p
, 0);
p
->fts_level
= FTS_ROOTLEVEL
;
if (compar
&& nitems
> 1)
root
= fts_sort(sp
, root
, nitems
);
* Allocate a dummy pointer and make fts_read think that we've just
* finished the node before the root(s); set p->fts_info to FTS_NS
* so that everything about the "current" node is ignored.
if (!(sp
->fts_cur
= fts_alloc(sp
, "", 0)))
sp
->fts_cur
->fts_link
= root
;
sp
->fts_cur
->fts_info
= FTS_NS
;
/* Start out with at least 1K+ of path space. */
if (!fts_path(sp
, MAX(maxlen
, MAXPATHLEN
)))
* If using chdir(2), grab a file descriptor pointing to dot to insure
* that we can get back here; this could be avoided for some paths,
* but almost certainly not worth the effort. Slashes, symbolic links,
* and ".." are all fairly nasty problems. Note, if we can't get the
* descriptor we run anyway, just more slowly.
if (!ISSET(FTS_NOCHDIR
) && (sp
->fts_rfd
= open(".", O_RDONLY
, 0)) < 0)
* Load the stream structure for the next traversal. Since we don't
* actually enter the directory until after the preorder visit, set
* the fts_accpath field specially so the chdir gets done to the right
* place and the user can access the first node.
len
= p
->fts_pathlen
= p
->fts_namelen
;
bcopy(p
->fts_name
, sp
->fts_path
, len
+ 1);
if ((cp
= rindex(p
->fts_name
, '/')) && (cp
!= p
->fts_name
|| cp
[1])) {
bcopy(cp
, p
->fts_name
, len
+ 1);
p
->fts_accpath
= p
->fts_path
= sp
->fts_path
;
sp
->rdev
= p
->fts_statb
.st_dev
;
p
->fts_info
= fts_stat(sp
, p
, 0);
register FTSENT
*freep
, *p
;
* This still works if we haven't read anything -- the dummy
* structure points to the root list, so we step through to
* the end of the root list which has a valid parent pointer.
for (p
= sp
->fts_cur
; p
->fts_level
> FTS_ROOTPARENTLEVEL
;) {
p
= p
->fts_link
? p
->fts_link
: p
->fts_parent
;
/* Free up child linked list, sort array, path buffer. */
fts_lfree(sp
->fts_child
);
/* Return to original directory, save errno if necessary. */
if (!ISSET(FTS_NOCHDIR
)) {
saved_errno
= fchdir(sp
->fts_rfd
) ? errno
: 0;
(void)close(sp
->fts_rfd
);
/* Free up the stream pointer. */
/* Set errno and return. */
if (!ISSET(FTS_NOCHDIR
) && saved_errno
) {
* Special case a root of "/" so that slashes aren't appended causing
* paths to be written as "//foo".
(p->fts_level == FTS_ROOTLEVEL && p->fts_pathlen == 1 && \
p->fts_path[0] == '/' ? 0 : p->fts_pathlen)
register FTSENT
*p
, *tmp
;
/* If finished or unrecoverable error, return NULL. */
if (!sp
->fts_cur
|| ISSET(FTS_STOP
))
/* Set current node pointer. */
/* Save and zero out user instructions. */
p
->fts_instr
= FTS_NOINSTR
;
/* If used fts_link pointer for cycle detection, restore it. */
p
->fts_link
= sp
->fts_savelink
;
/* Any type of file may be re-visited; re-stat and re-turn. */
if (instr
== FTS_AGAIN
) {
p
->fts_info
= fts_stat(sp
, p
, 0);
* Following a symlink -- SLNONE test allows application to see
if (instr
== FTS_FOLLOW
&&
(p
->fts_info
== FTS_SL
|| p
->fts_info
== FTS_SLNONE
)) {
p
->fts_info
= fts_stat(sp
, p
, 1);
/* Directory in pre-order. */
if (p
->fts_info
== FTS_D
) {
/* If skipped or crossed mount point, do post-order visit. */
ISSET(FTS_XDEV
) && p
->fts_statb
.st_dev
!= sp
->rdev
) {
fts_lfree(sp
->fts_child
);
* Cd to the subdirectory, reading it if haven't already. If
* the read fails for any reason, or the directory is empty,
* the fts_info field of the current node is set by fts_build.
* If have already read and now fail to chdir, whack the list
* to make the names come out right, and set the parent state
* so the application will eventually get an error condition.
* If haven't read and fail to chdir, check to see if we're
* at the root node -- if so, we have to get back or the root
* node may be inaccessible.
if (CHDIR(sp
, p
->fts_accpath
)) {
p
->fts_parent
->fts_cderr
= errno
;
for (p
= sp
->fts_child
; p
; p
= p
->fts_link
)
p
->fts_parent
->fts_accpath
;
} else if (!(sp
->fts_child
= fts_build(sp
, BREAD
))) {
if (p
->fts_level
== FTS_ROOTLEVEL
&&
FCHDIR(sp
, sp
->fts_rfd
)) {
/* Move to next node on this level. */
/* If reached the top, load the paths for the next root. */
if (p
->fts_level
== FTS_ROOTLEVEL
) {
/* User may have called fts_set on the node. */
if (p
->fts_instr
== FTS_SKIP
)
if (p
->fts_instr
== FTS_FOLLOW
) {
p
->fts_info
= fts_stat(sp
, p
, 1);
p
->fts_instr
= FTS_NOINSTR
;
name
: t
= sp
->fts_path
+ NAPPEND(p
->fts_parent
);
bcopy(p
->fts_name
, t
, p
->fts_namelen
+ 1);
/* Move up to the parent node. */
if (p
->fts_level
== FTS_ROOTPARENTLEVEL
) {
* Done; free everything up and set errno to 0 so the user
* can distinguish between error and EOF.
return(sp
->fts_cur
= NULL
);
sp
->fts_path
[p
->fts_pathlen
] = '\0';
* Cd back up to the parent directory. If at a root node, have to cd
* back to the original place, otherwise may not be able to access the
* original node on post-order.
if (p
->fts_level
== FTS_ROOTLEVEL
) {
if (FCHDIR(sp
, sp
->fts_rfd
)) {
else if (CHDIR(sp
, "..")) {
* If had a chdir error when trying to get into the directory, set the
* info field to reflect this, and restore errno. The error indicator
* has to be reset to 0 so that if the user does an FTS_AGAIN, it all
* Fts_set takes the stream as an argument although it's not used in this
* implementation; it would be necessary if anyone wanted to add global
* semantics to fts using fts_set. An error return is allowed for similar
/* Set current node pointer. */
* Set errno to 0 so that user can tell the difference between an
* error and a directory without entries. If not a directory being
* visited in *pre-order*, or we've already had fatal errors, return
if (ISSET(FTS_STOP
) || p
->fts_info
!= FTS_D
&& p
->fts_info
!= FTS_DNR
)
/* Free up any previous child list. */
fts_lfree(sp
->fts_child
);
* If using chdir on a relative path and called BEFORE fts_read does
* its chdir to the root of a traversal, we can lose -- we need to
* chdir into the subdirectory, and we don't know where the current
* directory is, so we can't get back so that the upcoming chdir by
if (p
->fts_level
!= FTS_ROOTLEVEL
|| p
->fts_accpath
[0] == '/' ||
return(sp
->fts_child
= fts_build(sp
, BCHILD
));
if ((fd
= open(".", O_RDONLY
, 0)) < 0)
sp
->fts_child
= fts_build(sp
, BCHILD
);
* This is the tricky part -- do not casually change *anything* in here. The
* idea is to build the linked list of entries that are used by fts_children
* and fts_read. There are lots of special cases.
* The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
* set and it's a physical walk (so that symbolic links can't be directories),
* we assume that the number of subdirectories in a node is equal to the number
* of links to the parent. This allows stat calls to be skipped in any leaf
* directories and for any nodes after the directories in the parent node have
* been found. This empirically cuts the stat calls by about 2/3.
#define ISDOT(a) (a[0] == '.' && (!a[1] || a[1] == '.' && !a[2]))
register struct dirent
*dp
;
register FTSENT
*p
, *head
;
int cderr
, descend
, len
, level
, maxlen
, nlinks
, saved_errno
;
/* Set current node pointer. */
* Open the directory for reading. If this fails, we're done.
* If being called from fts_read, set the fts_info field.
if (!(dirp
= opendir(cur
->fts_accpath
))) {
* Nlinks is the number of possible entries of type directory in the
* directory if we're cheating on stat calls, 0 if we're not doing
* any stat calls at all, -1 if we're doing stats on everything.
ISSET(FTS_NOSTAT
) && ISSET(FTS_PHYSICAL
) ?
cur
->fts_statb
.st_nlink
- (ISSET(FTS_SEEDOT
) ? 0 : 2) : -1;
* If we're going to need to stat anything or we want to descend
* and stay in the directory, chdir. If this fails we keep going.
* We won't be able to stat anything, but we can still return the
* names themselves. Note, that since fts_read won't be able to
* chdir into the directory, it will have to return different path
* names than before, i.e. "a/b" instead of "b". Since the node
* has already been visited in pre-order, have to wait until the
* post-order visit to return the error. This is all fairly nasty.
* If a program needed sorted entries or stat information, they had
* better be checking FTS_NS on the returned nodes.
if (nlinks
|| type
== BREAD
)
if (FCHDIR(sp
, dirfd(dirp
))) {
* Figure out the max file name length that can be stored in the
* current path -- the inner loop allocates more path as necessary.
* We really wouldn't have to do the maxlen calculations here, we
* could do them in fts_read before returning the path, but it's a
* lot easier here since the length is part of the dirent structure.
* If not changing directories set a pointer so that we can just
* append each new name into the path.
maxlen
= sp
->fts_pathlen
- cur
->fts_pathlen
- 1;
if (ISSET(FTS_NOCHDIR
)) {
level
= cur
->fts_level
+ 1;
/* Read the directory, attaching each entry to the `link' pointer. */
for (head
= NULL
, nitems
= 0; dp
= readdir(dirp
);) {
if (!ISSET(FTS_SEEDOT
) && ISDOT(dp
->d_name
))
if (!(p
= fts_alloc(sp
, dp
->d_name
, (int)dp
->d_namlen
)))
if (dp
->d_namlen
> maxlen
) {
if (!fts_path(sp
, (int)dp
->d_namlen
)) {
* No more memory for path or structures. Save
* errno, free up the current structure and the
* structures already allocated.
mem1
: saved_errno
= errno
;
maxlen
= sp
->fts_pathlen
- sp
->fts_cur
->fts_pathlen
- 1;
p
->fts_pathlen
= len
+ dp
->d_namlen
+ 1;
p
->fts_parent
= sp
->fts_cur
;
/* Build a file name for fts_stat to stat. */
if (ISSET(FTS_NOCHDIR
)) {
p
->fts_accpath
= p
->fts_path
;
bcopy(p
->fts_name
, cp
, p
->fts_namelen
+ 1);
p
->fts_accpath
= p
->fts_name
;
p
->fts_info
= fts_stat(sp
, p
, 0);
if (nlinks
> 0 && p
->fts_info
== FTS_D
)
p
->fts_info
= ISSET(FTS_NOSTAT
) ? FTS_NSOK
: FTS_NS
;
p
->fts_accpath
= cur
->fts_accpath
;
ISSET(FTS_NOCHDIR
) ? p
->fts_path
: p
->fts_name
;
* If not changing directories, reset the path back to original
if (ISSET(FTS_NOCHDIR
)) {
if (cp
- 1 > sp
->fts_path
)
* If descended after called from fts_children or called from
* fts_read and didn't find anything, get back. If can't get
if (descend
&& (!nitems
|| type
== BCHILD
) && CHDIR(sp
, "..")) {
/* If we didn't find anything, just do the post-order visit */
if (sp
->fts_compar
&& nitems
> 1)
head
= fts_sort(sp
, head
, nitems
);
* If doing a logical walk, or application requested FTS_FOLLOW, do
* a stat(2). If that fails, check for a non-existent symlink. If
* fail, return the errno from the stat call.
if (ISSET(FTS_LOGICAL
) || follow
) {
if (stat(p
->fts_accpath
, &p
->fts_statb
)) {
if (!lstat(p
->fts_accpath
, &p
->fts_statb
)) {
bzero(&p
->fts_statb
, sizeof(struct stat
));
} else if (lstat(p
->fts_accpath
, &p
->fts_statb
)) {
bzero(&p
->fts_statb
, sizeof(struct stat
));
* Cycle detection is done as soon as we find a directory. Detection
* is by brute force; if the tree gets deep enough or the number of
* symbolic links to directories high enough something faster might
if (S_ISDIR(p
->fts_statb
.st_mode
)) {
dev
= p
->fts_statb
.st_dev
;
ino
= p
->fts_statb
.st_ino
;
for (t
= p
->fts_parent
; t
->fts_level
> FTS_ROOTLEVEL
;
if (ino
== t
->fts_statb
.st_ino
&&
dev
== t
->fts_statb
.st_dev
) {
sp
->fts_savelink
= p
->fts_link
;
if (S_ISLNK(p
->fts_statb
.st_mode
))
if (S_ISREG(p
->fts_statb
.st_mode
))
#define R(type, nelem, ptr) \
(type *)realloc((void *)ptr, (u_int)((nelem) * sizeof(type)))
fts_sort(sp
, head
, nitems
)
register FTSENT
**ap
, *p
;
* Construct an array of pointers to the structures and call qsort(3).
* Reassemble the array in the order returned by qsort. If unable to
* sort for memory reasons, return the directory entries in their
* current order. Allocate enough space for the current needs plus
* 40 so we don't realloc one entry at a time.
if (nitems
> sp
->fts_nitems
) {
sp
->fts_nitems
= nitems
+ 40;
R(FTSENT
*, sp
->fts_nitems
, sp
->fts_array
))) {
for (ap
= sp
->fts_array
, p
= head
; p
; p
= p
->fts_link
)
qsort((void *)sp
->fts_array
, nitems
, sizeof(FTSENT
*), sp
->fts_compar
);
for (head
= *(ap
= sp
->fts_array
); --nitems
; ++ap
)
* Variable sized structures; the name is the last element so
* we allocate enough extra space after the structure to store
if (!(p
= (FTSENT
*)malloc((size_t)(sizeof(FTSENT
) + len
))))
bcopy(name
, p
->fts_name
, len
+ 1);
p
->fts_path
= sp
->fts_path
;
p
->fts_instr
= FTS_NOINSTR
;
/* Free a linked list of structures. */
* Allow essentially unlimited paths; certain programs (find, rm, ls) need to
* work on any tree. Most systems will allow creation of paths much longer
* than MAXPATHLEN, even though the kernel won't resolve them. Add an extra
* 128 bytes to the requested size so that we don't realloc the path 2 bytes
sp
->fts_pathlen
+= size
+ 128;
return(sp
->fts_path
= R(char, sp
->fts_pathlen
, sp
->fts_path
));