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fts_load no longer has any return value
[unix-history] / usr / src / lib / libc / gen / fts.c
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)fts.c 5.18 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include "fts.h"
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
static FTSENT *fts_alloc(), *fts_build(), *fts_sort();
static void fts_load(), fts_lfree();
static u_short fts_stat();
static char *fts_path();
#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))
/* fts_build flags */
#define BCHILD 1 /* from fts_children */
#define BREAD 2 /* from fts_read */
FTS *
fts_open(argv, options, compar)
char * const *argv;
register int options;
int (*compar)();
{
register FTS *sp;
register FTSENT *p, *root;
register int nitems, maxlen;
FTSENT *parent, *tmp;
int len;
/* Allocate/initialize the stream */
if (!(sp = (FTS *)malloc((u_int)sizeof(FTS))))
return(NULL);
bzero(sp, sizeof(FTS));
sp->fts_compar = compar;
sp->fts_options = options;
/* Logical walks turn on NOCHDIR; symbolic links are too hard. */
if (ISSET(FTS_LOGICAL))
SET(FTS_NOCHDIR);
/* Allocate/initialize root's parent. */
if (!(parent = fts_alloc(sp, "", 0)))
goto mem1;
parent->fts_level = FTS_ROOTPARENTLEVEL;
/* Allocate/initialize root(s). */
maxlen = -1;
for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
if (!(len = strlen(*argv))) {
errno = ENOENT;
goto mem2;
}
if (maxlen < len)
maxlen = len;
p = fts_alloc(sp, *argv, len);
/*
* If comparison routine supplied, traverse in sorted
* order; otherwise traverse in the order specified.
*/
if (compar) {
p->fts_link = root;
root = p;
p->fts_accpath = p->fts_name;
if (!(options & FTS_NOSTAT))
p->fts_info = fts_stat(sp, p, 0);
} else {
p->fts_link = NULL;
if (!root)
tmp = root = p;
else {
tmp->fts_link = p;
tmp = p;
}
}
p->fts_level = FTS_ROOTLEVEL;
p->fts_parent = parent;
}
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)))
goto mem2;
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)))
goto mem3;
/*
* 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)
SET(FTS_NOCHDIR);
return(sp);
mem3: free(sp->fts_cur);
mem2: fts_lfree(root);
free(parent);
mem1: free(sp);
return(NULL);
}
static void
fts_load(sp, p)
FTS *sp;
register FTSENT *p;
{
register int len;
register char *cp;
/*
* 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])) {
len = strlen(++cp);
bcopy(cp, p->fts_name, len + 1);
p->fts_namelen = len;
}
p->fts_accpath = p->fts_path = sp->fts_path;
p->fts_info = fts_stat(sp, p, 0);
sp->rdev = p->fts_statb.st_dev;
}
fts_close(sp)
FTS *sp;
{
register FTSENT *freep, *p;
int saved_errno;
if (sp->fts_cur) {
/*
* 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;) {
freep = p;
p = p->fts_link ? p->fts_link : p->fts_parent;
free(freep);
}
free(p);
}
/* Free up child linked list, sort array, path buffer. */
if (sp->fts_child)
fts_lfree(sp->fts_child);
if (sp->fts_array)
free(sp->fts_array);
free(sp->fts_path);
/* 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. */
free(sp);
/* Set errno and return. */
if (!ISSET(FTS_NOCHDIR) && saved_errno) {
errno = saved_errno;
return(-1);
}
return(0);
}
/*
* Special case a root of "/" so that slashes aren't appended causing
* paths to be written as "//foo".
*/
#define NAPPEND(p) \
(p->fts_level == FTS_ROOTLEVEL && p->fts_pathlen == 1 && \
p->fts_path[0] == '/' ? 0 : p->fts_pathlen)
FTSENT *
fts_read(sp)
register FTS *sp;
{
register FTSENT *p, *tmp;
register int instr;
register char *t;
/* If finished or unrecoverable error, return NULL. */
if (!sp->fts_cur || ISSET(FTS_STOP))
return(NULL);
/* Set current node pointer. */
p = sp->fts_cur;
/* Save and zero out user instructions. */
instr = p->fts_instr;
p->fts_instr = FTS_NOINSTR;
/* If used fts_link pointer for cycle detection, restore it. */
if (sp->fts_savelink) {
p->fts_link = sp->fts_savelink;
sp->fts_savelink = NULL;
}
/* 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);
return(p);
}
/*
* Following a symlink -- SLNONE test allows application to see
* SLNONE and recover.
*/
if (instr == FTS_FOLLOW &&
(p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
p->fts_info = fts_stat(sp, p, 1);
return(p);
}
/* Directory in pre-order. */
if (p->fts_info == FTS_D) {
/* If skipped or crossed mount point, do post-order visit. */
if (instr == FTS_SKIP ||
ISSET(FTS_XDEV) && p->fts_statb.st_dev != sp->rdev) {
if (sp->fts_child) {
fts_lfree(sp->fts_child);
sp->fts_child = NULL;
}
p->fts_info = FTS_DP;
return(p);
}
/*
* 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 (sp->fts_child) {
if (CHDIR(sp, p->fts_accpath)) {
p->fts_parent->fts_cderr = errno;
for (p = sp->fts_child; p; p = p->fts_link)
p->fts_accpath =
p->fts_parent->fts_accpath;
}
} else if (!(sp->fts_child = fts_build(sp, BREAD))) {
if ISSET(FTS_STOP)
return(NULL);
if (p->fts_level == FTS_ROOTLEVEL &&
FCHDIR(sp, sp->fts_rfd)) {
SET(FTS_STOP);
return(NULL);
}
return(p);
}
p = sp->fts_child;
sp->fts_child = NULL;
goto name;
}
/* Move to next node on this level. */
next: tmp = p;
if (p = p->fts_link) {
free(tmp);
/* If reached the top, load the paths for the next root. */
if (p->fts_level == FTS_ROOTLEVEL) {
fts_load(sp, p);
return(sp->fts_cur = p);
}
/* User may have called fts_set on the node. */
if (p->fts_instr == FTS_SKIP)
goto next;
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);
*t++ = '/';
bcopy(p->fts_name, t, p->fts_namelen + 1);
return(sp->fts_cur = p);
}
/* Move up to the parent node. */
p = tmp->fts_parent;
free(tmp);
if (p->fts_level == FTS_ROOTPARENTLEVEL) {
/*
* Done; free everything up and set errno to 0 so the user
* can distinguish between error and EOF.
*/
free(p);
errno = 0;
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)) {
SET(FTS_STOP);
return(NULL);
}
}
else if (CHDIR(sp, "..")) {
SET(FTS_STOP);
return(NULL);
}
/*
* 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
* works.
*/
if (p->fts_cderr) {
errno = p->fts_cderr;
p->fts_cderr = 0;
p->fts_info = FTS_ERR;
} else
p->fts_info = FTS_DP;
return(sp->fts_cur = p);
}
/*
* 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
* reasons.
*/
/* ARGSUSED */
fts_set(sp, p, instr)
FTS *sp;
FTSENT *p;
int instr;
{
p->fts_instr = instr;
return(0);
}
FTSENT *
fts_children(sp)
register FTS *sp;
{
register FTSENT *p;
int fd;
/* Set current node pointer. */
p = sp->fts_cur;
/*
* 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
* immediately.
*/
errno = 0;
if (ISSET(FTS_STOP) || p->fts_info != FTS_D && p->fts_info != FTS_DNR)
return(NULL);
/* Free up any previous child list. */
if (sp->fts_child)
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
* fts_read will work.
*/
if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
ISSET(FTS_NOCHDIR))
return(sp->fts_child = fts_build(sp, BCHILD));
if ((fd = open(".", O_RDONLY, 0)) < 0)
return(NULL);
sp->fts_child = fts_build(sp, BCHILD);
if (fchdir(fd))
return(NULL);
(void)close(fd);
return(sp->fts_child);
}
/*
* 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]))
static FTSENT *
fts_build(sp, type)
register FTS *sp;
int type;
{
register struct dirent *dp;
register FTSENT *p, *head;
register int nitems;
FTSENT *cur;
DIR *dirp;
int cderr, descend, len, level, maxlen, nlinks, saved_errno;
char *cp;
/* Set current node pointer. */
cur = sp->fts_cur;
/*
* 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))) {
if (type == BREAD)
cur->fts_info = FTS_DNR;
return(NULL);
}
/*
* 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.
*/
nlinks =
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))) {
if (type == BREAD)
cur->fts_cderr = errno;
descend = nlinks = 0;
cderr = 1;
} else {
descend = 1;
cderr = 0;
}
else
descend = 0;
/*
* 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;
len = NAPPEND(cur);
if (ISSET(FTS_NOCHDIR)) {
cp = sp->fts_path + len;
*cp++ = '/';
}
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))
continue;
if (!(p = fts_alloc(sp, dp->d_name, (int)dp->d_namlen)))
goto mem1;
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;
if (p)
free(p);
fts_lfree(head);
(void)closedir(dirp);
errno = saved_errno;
cur->fts_info = FTS_ERR;
SET(FTS_STOP);
return(NULL);
}
maxlen = sp->fts_pathlen - sp->fts_cur->fts_pathlen - 1;
}
p->fts_pathlen = len + dp->d_namlen + 1;
p->fts_parent = sp->fts_cur;
p->fts_level = level;
if (nlinks) {
/* 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);
} else
p->fts_accpath = p->fts_name;
p->fts_info = fts_stat(sp, p, 0);
if (nlinks > 0 && p->fts_info == FTS_D)
--nlinks;
} else if (cderr) {
p->fts_info = ISSET(FTS_NOSTAT) ? FTS_NSOK : FTS_NS;
p->fts_accpath = cur->fts_accpath;
} else {
p->fts_accpath =
ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
p->fts_info = FTS_NSOK;
}
p->fts_link = head;
head = p;
++nitems;
}
(void)closedir(dirp);
/*
* If not changing directories, reset the path back to original
* state.
*/
if (ISSET(FTS_NOCHDIR)) {
if (cp - 1 > sp->fts_path)
--cp;
*cp = '\0';
}
/*
* If descended after called from fts_children or called from
* fts_read and didn't find anything, get back. If can't get
* back, we're done.
*/
if (descend && (!nitems || type == BCHILD) && CHDIR(sp, "..")) {
cur->fts_info = FTS_ERR;
SET(FTS_STOP);
return(NULL);
}
/* If we didn't find anything, just do the post-order visit */
if (!nitems) {
if (type == BREAD)
cur->fts_info = FTS_DP;
return(NULL);
}
/* Sort the entries. */
if (sp->fts_compar && nitems > 1)
head = fts_sort(sp, head, nitems);
return(head);
}
static u_short
fts_stat(sp, p, follow)
FTS *sp;
register FTSENT *p;
int follow;
{
int saved_errno;
/*
* 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)) {
saved_errno = errno;
if (!lstat(p->fts_accpath, &p->fts_statb)) {
errno = 0;
return(FTS_SLNONE);
}
errno = saved_errno;
bzero(&p->fts_statb, sizeof(struct stat));
return(FTS_NS);
}
} else if (lstat(p->fts_accpath, &p->fts_statb)) {
bzero(&p->fts_statb, sizeof(struct stat));
return(FTS_NS);
}
/*
* 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
* be worthwhile.
*/
if (S_ISDIR(p->fts_statb.st_mode)) {
register FTSENT *t;
register dev_t dev;
register ino_t ino;
dev = p->fts_statb.st_dev;
ino = p->fts_statb.st_ino;
for (t = p->fts_parent; t->fts_level > FTS_ROOTLEVEL;
t = t->fts_parent)
if (ino == t->fts_statb.st_ino &&
dev == t->fts_statb.st_dev) {
sp->fts_savelink = p->fts_link;
p->fts_link = t;
return(FTS_DC);
}
return(FTS_D);
}
if (S_ISLNK(p->fts_statb.st_mode))
return(FTS_SL);
if (S_ISREG(p->fts_statb.st_mode))
return(FTS_F);
return(FTS_DEFAULT);
}
#define R(type, nelem, ptr) \
(type *)realloc((void *)ptr, (u_int)((nelem) * sizeof(type)))
static FTSENT *
fts_sort(sp, head, nitems)
FTS *sp;
FTSENT *head;
register int 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;
if (!(sp->fts_array =
R(FTSENT *, sp->fts_nitems, sp->fts_array))) {
sp->fts_nitems = 0;
return(head);
}
}
for (ap = sp->fts_array, p = head; p; p = p->fts_link)
*ap++ = p;
qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), sp->fts_compar);
for (head = *(ap = sp->fts_array); --nitems; ++ap)
ap[0]->fts_link = ap[1];
ap[0]->fts_link = NULL;
return(head);
}
static FTSENT *
fts_alloc(sp, name, len)
FTS *sp;
char *name;
register int len;
{
register FTSENT *p;
/*
* Variable sized structures; the name is the last element so
* we allocate enough extra space after the structure to store
* it.
*/
if (!(p = (FTSENT *)malloc((size_t)(sizeof(FTSENT) + len))))
return(NULL);
bcopy(name, p->fts_name, len + 1);
p->fts_namelen = len;
p->fts_path = sp->fts_path;
p->fts_instr = FTS_NOINSTR;
p->fts_cderr = 0;
p->fts_number = 0;
p->fts_pointer = NULL;
return(p);
}
static void
fts_lfree(head)
register FTSENT *head;
{
register FTSENT *p;
/* Free a linked list of structures. */
while (p = head) {
head = head->fts_link;
free(p);
}
}
/*
* 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
* at a time.
*/
static char *
fts_path(sp, size)
FTS *sp;
int size;
{
sp->fts_pathlen += size + 128;
return(sp->fts_path = R(char, sp->fts_pathlen, sp->fts_path));
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.