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wasn't resetting errno for fts_children call of fts_build for
[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 5.12 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <fts.h>
#include <string.h>
#include <stdlib.h>
FTSENT *fts_alloc(), *fts_build(), *fts_cycle(), *fts_root(), *fts_sort();
void fts_lfree(), fts_load();
u_short fts_stat();
/*
* Special case a root of "/" so that slashes aren't appended causing
* paths to be written as "//foo".
*/
#define NAPPEND(p) \
(p->fts_level == ROOTLEVEL && p->fts_pathlen == 1 && \
p->fts_path[0] == '/' ? 0 : p->fts_pathlen)
#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_level values */
#define ROOTLEVEL 0
#define ROOTPARENTLEVEL -1
FTS *
fts_open(argv, options, compar)
char *argv[];
register int options;
int (*compar)();
{
register FTS *sp;
register FTSENT *p, *root;
register int nitems, maxlen;
FTSENT *parent, *tmp;
char *fts_path();
/* 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 = ROOTPARENTLEVEL;
/* Allocate/initialize root(s). */
maxlen = -1;
for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
if (!(p = fts_root(sp, *argv)))
goto mem2;
if (maxlen < p->fts_namelen)
maxlen = p->fts_namelen;
/*
* 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 = 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_sd = open(".", O_RDONLY, 0)) < 0)
SET(FTS_NOCHDIR);
return(sp);
mem3: free((void *)sp->fts_cur);
mem2: fts_lfree(root);
free((void *)parent);
mem1: free((void *)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; 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;
}
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 > ROOTPARENTLEVEL;) {
freep = p;
p = p->fts_link ? p->fts_link : p->fts_parent;
free((void *)freep);
}
free((void *)p);
}
/* Free up child linked list, sort array, path buffer. */
if (sp->fts_child)
fts_lfree(sp->fts_child);
if (sp->fts_array)
free((void *)sp->fts_array);
free((char *)sp->fts_path);
/*
* Return to original directory, save errno if necessary; free up
* the directory buffer.
*/
if (!ISSET(FTS_NOCHDIR)) {
saved_errno = fchdir(sp->fts_sd) ? errno : 0;
(void)close(sp->fts_sd);
}
/* Free up the stream pointer. */
free((void *)sp);
/* Set errno and return. */
if (!ISSET(FTS_NOCHDIR) && saved_errno) {
errno = saved_errno;
return(-1);
}
return(0);
}
FTSENT *
fts_read(sp)
register FTS *sp;
{
register FTSENT *p, *tmp;
register int instr;
register char *cp;
static int cd;
/* 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 return. */
if (instr == FTS_AGAIN) {
p->fts_info = fts_stat(sp, p, 0);
return(p);
}
/* Following a symbolic link. */
if (p->fts_info == FTS_SL && instr == FTS_FOLLOW) {
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->sdev) {
if (sp->fts_child) {
fts_lfree(sp->fts_child);
sp->fts_child = NULL;
}
p->fts_info = FTS_DP;
return(p);
}
/* Read the directory if necessary, and return first entry. */
if (sp->fts_child)
if (CHDIR(sp, p->fts_accpath)) {
fts_lfree(sp->fts_child);
p->fts_info = FTS_DNX;
} else {
p = sp->fts_child;
cp = sp->fts_path + NAPPEND(p->fts_parent);
*cp++ = '/';
bcopy(p->fts_name, cp, p->fts_namelen + 1);
}
else {
if (!(sp->fts_child = fts_build(sp, BREAD)))
return(p);
p = sp->fts_child;
}
sp->fts_child = NULL;
return(sp->fts_cur = p);
}
/* Move to next node on this level. */
next: tmp = p;
if (p = p->fts_link) {
/*
* If root level node, set up paths and return. If not the
* first time, and it's not an absolute pathname, get back
* to starting directory. If that fails, we're dead.
*/
if (p->fts_level == ROOTLEVEL) {
fts_load(sp, p);
free((void *)tmp);
if (cd &&
p->fts_path[0] != '/' && FCHDIR(sp, sp->fts_sd)) {
/* Can't get back to start; we're dead. */
p->fts_path = "starting directory";
p->fts_info = FTS_ERR;
SET(FTS__STOP);
return(sp->fts_cur = p);
}
cd = 1;
p->fts_info = fts_stat(sp, p, 0);
sp->sdev = p->fts_statb.st_dev;
} else {
free((void *)tmp);
/* User may have called fts_set on 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;
}
/* Fill in the paths. */
cp = sp->fts_path + NAPPEND(p->fts_parent);
*cp++ = '/';
bcopy(p->fts_name, cp, p->fts_namelen + 1);
/* Check for directory cycles. */
if (p->fts_info == FTS_D && (tmp = fts_cycle(p))) {
sp->fts_savelink = p->fts_link;
p->fts_link = tmp;
p->fts_info = FTS_DC;
}
}
return(sp->fts_cur = p);
}
/* Move to parent. */
p = tmp->fts_parent;
free((void *)tmp);
if (p->fts_level == ROOTPARENTLEVEL) {
/*
* Done; free everything up and set errno to 0 so the user
* can distinguish between error and EOF.
*/
free((void *)p);
errno = 0;
return(sp->fts_cur = NULL);
}
sp->fts_path[p->fts_pathlen] = '\0';
if (CHDIR(sp, "..")) {
SET(FTS__STOP);
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.
*/
errno = 0;
if (ISSET(FTS__STOP) ||
p->fts_info != FTS_D && p->fts_info != FTS_DNX &&
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 because we need
* to chdir into the subdirectory, and we don't know where the current
* directory is to get back so that the upcoming chdir by fts_read
* will work.
*/
if (p->fts_level != 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);
}
#define ISDOT(a) (a[0] == '.' && (!a[1] || a[1] == '.' && !a[2]))
FTSENT *
fts_build(sp, type)
register FTS *sp;
int type;
{
register struct dirent *dp;
register FTSENT *p, *head;
register int nitems;
DIR *dirp;
int descend, len, level, maxlen, nlinks, saved_errno;
char *cp;
/* Set current node pointer. */
p = sp->fts_cur;
if (!(dirp = opendir(p->fts_accpath))) {
if (type == BREAD) {
p->fts_info = FTS_DNR;
errno = 0;
}
return(NULL);
}
/*
* 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), fts assumes 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.
*/
nlinks =
ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL) ?
p->fts_statb.st_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2) : -1;
/* If told to descend or found links and not told not to descend. */
descend = 0;
if (nlinks || type == BREAD)
if (!FCHDIR(sp, dirfd(dirp)))
descend = 1;
/*
* Return all the information possible; an fts_read doing a
* relative walk of the tree will have to descend, so it can't
* succeed. Fts_children or absolute walks of the tree can
* succeed, but no stat information will be available. Reset
* errno as necessary.
*/
else {
errno = 0;
if (type == BREAD) {
(void)closedir(dirp);
p->fts_info = FTS_DNX;
return(NULL);
}
nlinks = 0;
}
/* Get max file name length that can be stored in current path. */
maxlen = sp->fts_pathlen - p->fts_pathlen - 1;
cp = sp->fts_path + (len = NAPPEND(p));
*cp++ = '/';
level = p->fts_level + 1;
/* Read the directory, attching each new entry to the `link' pointer. */
for (head = NULL, nitems = 0; dp = readdir(dirp);) {
if (ISDOT(dp->d_name) && !ISSET(FTS_SEEDOT))
continue;
if (!(p = fts_alloc(sp, dp->d_name, (int)dp->d_namlen))) {
saved_errno = errno;
goto mem1;
}
if (dp->d_namlen > maxlen) {
if (!fts_path(sp, (int)dp->d_namlen)) {
/* Quit: this stream no longer has a path. */
SET(FTS__STOP);
saved_errno = errno;
free((void *)p);
mem1: fts_lfree(head);
if (type == BREAD)
p->fts_info = FTS_ERR;
if (descend && CHDIR(sp, "..")) {
/*
* chdir error is more interesting
* than memory error, since it stops
* everything.
*/
saved_errno = errno;
SET(FTS__STOP);
}
errno = saved_errno;
(void)closedir(dirp);
return(NULL);
}
maxlen = sp->fts_pathlen - sp->fts_cur->fts_pathlen - 1;
}
p->fts_pathlen = len + dp->d_namlen + 1;
p->fts_accpath = ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
p->fts_parent = sp->fts_cur;
p->fts_level = level;
if (nlinks) {
/* Make sure fts_stat has a filename to stat. */
if (ISSET(FTS_NOCHDIR))
bcopy(p->fts_name, cp, p->fts_namelen + 1);
p->fts_info = fts_stat(sp, p, 0);
if (nlinks > 0 && (p->fts_info == FTS_D ||
p->fts_info == FTS_DNR || p->fts_info == FTS_DNX))
--nlinks;
} else
p->fts_info = FTS_NS;
p->fts_link = head;
head = p;
++nitems;
}
(void)closedir(dirp);
/* Reset the path. */
if (cp - 1 > sp->fts_path)
--cp;
*cp = '\0';
/*
* If descended: if were called from fts_read and didn't find anything,
* or were called from fts_children, get back.
*/
if (descend && (!nitems || type == BCHILD) && CHDIR(sp, "..")) {
SET(FTS__STOP);
p->fts_info = FTS_ERR;
return(NULL);
}
if (!nitems) {
if (type == BREAD)
p->fts_info = FTS_DP;
return(NULL);
}
if (sp->fts_compar && nitems > 1)
head = fts_sort(sp, head, nitems);
if (type == BREAD) {
*cp = '/';
bcopy(head->fts_name, cp + 1, head->fts_namelen + 1);
}
return(head);
}
static u_short
fts_stat(sp, p, follow)
FTS *sp;
register FTSENT *p;
int follow;
{
/*
* If doing a logical walk, or application requested FTS_FOLLOW, do
* a stat(2). If that fails, either fail or do an lstat(2) for a
* non-existent symlink. (The check has to be done, or we wouldn't
* detect a symlink being deleted.)
*
* Don't leave errno set for FTS_NS cases. XXX
*/
if (ISSET(FTS_LOGICAL) || follow) {
if (stat(p->fts_accpath, &p->fts_statb)) {
errno = 0;
if (follow && !lstat(p->fts_accpath, &p->fts_statb))
return(FTS_SLNONE);
else {
errno = 0;
return(FTS_NS);
}
}
} else if (lstat(p->fts_accpath, &p->fts_statb)) {
errno = 0;
return(FTS_NS);
}
if (S_ISDIR(p->fts_statb.st_mode))
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);
}
static FTSENT *
fts_cycle(p)
register FTSENT *p;
{
register dev_t dev;
register ino_t ino;
/*
* Cycle detection is brute force; if the tree gets deep enough or
* the number of symbolic links to directories is really high
* something faster might be worthwhile.
*/
dev = p->fts_statb.st_dev;
ino = p->fts_statb.st_ino;
for (p = p->fts_parent; p->fts_level > ROOTLEVEL; p = p->fts_parent)
if (ino == p->fts_statb.st_ino && dev == p->fts_statb.st_dev)
return(p);
return(NULL);
}
#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
* allocate enough extra space after the structure to hold 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_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((void *)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)); }
static FTSENT *
fts_root(sp, name)
FTS *sp;
register char *name;
{
register char *cp;
/*
* Rip trailing slashes; it's somewhat unclear in POSIX 1003.1 what
* /a/b/ really is, they don't talk about what a null path component
* resolves to. This hopefully does what the user intended. Don't
* allow null pathnames.
*/
for (cp = name; *cp; ++cp);
if (cp == name) {
errno = ENOENT;
return(NULL);
}
while (--cp > name && *cp == '/');
*++cp = '\0';
return(fts_alloc(sp, name, cp - name));
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.