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change the names from foo to fts_foo
[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 5.4 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#include <fts.h>
#include <string.h>
extern int errno;
FTSENT *fts_alloc(), *fts_build(), *fts_cycle(), *fts_sort(), *fts_root();
short fts_stat();
char *malloc(), *realloc();
/*
* 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 CHDIR(sp, path) (!(sp->fts_options & FTS_NOCHDIR) && chdir(path))
#define FCHDIR(sp, fd) (!(sp->fts_options & FTS_NOCHDIR) && fchdir(fd))
#define ROOTLEVEL 0
#define ROOTPARENTLEVEL -1
static FTS *stream; /* current stream pointer */
FTS *
ftsopen(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 wd[MAXPATHLEN], *getwd(), *strdup();
/* allocate/initialize the stream */
if (!(stream = sp = (FTS *)malloc((u_int)sizeof(FTS))))
return(NULL);
bzero(sp, sizeof(FTS));
sp->fts_compar = compar;
sp->fts_options = options;
/* allocate/initialize root's parent */
if (!(parent = fts_alloc("", 0)))
goto mem1;
parent->fts_level = ROOTPARENTLEVEL;
/* allocate/initialize root(s) */
if (options & FTS_MULTIPLE) {
maxlen = -1;
for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
if (!(p = fts_root(*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;
p->fts_info = fts_stat(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(root, nitems);
} else {
if (!(root = fts_root((char *)argv)))
goto mem2;
maxlen = root->fts_namelen;
root->fts_link = NULL;
root->fts_level = ROOTLEVEL;
root->fts_parent = parent;
}
/* start out with at least 1K+ of path space */
if (!fts_path(MAX(maxlen, MAXPATHLEN)))
goto mem2;
/*
* some minor trickiness. Set the pointers so that ftsread thinks
* 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.
* Rather than allocate a dummy node use the root's parent's link
* pointer. This is handled specially in ftsclose() as well.
*/
sp->fts_cur = parent;
parent->fts_link = root;
parent->fts_info = FTS_NS;
/*
* if using chdir(2), do a getwd() to insure that we can get back
* here; this could be avoided for some paths, but probably not
* worth the effort. Slashes, symbolic links, and ".." are all
* fairly nasty problems. Note, if we can't get the current
* working directory we run anyway, just more slowly.
*/
if (!(options & FTS_NOCHDIR) &&
(!getwd(wd) || !(sp->fts_wd = strdup(wd))))
sp->fts_options |= FTS_NOCHDIR;
return(sp);
mem2: fts_lfree(root);
(void)free((char *)parent);
mem1: (void)free((char *)sp);
return(NULL);
}
static
fts_load(p)
register FTSENT *p;
{
register int len;
register char *cp;
/*
* load the stream structure for the next traversal; set the
* 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, stream->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 = stream->fts_path;
}
ftsclose(sp)
FTS *sp;
{
register FTSENT *freep, *p;
int saved_errno;
if (sp->fts_cur)
/* check for never having read anything */
if (sp->fts_cur->fts_level == ROOTPARENTLEVEL)
fts_lfree(sp->fts_cur);
else {
for (p = sp->fts_cur; p->fts_level > ROOTPARENTLEVEL;) {
freep = p;
p = p->fts_link ? p->fts_link : p->fts_parent;
(void)free((char *)freep);
}
(void)free((char *)p);
}
/* free up child linked list, sort array, path buffer */
if (sp->fts_child)
fts_lfree(sp->fts_child);
if (sp->fts_array)
(void)free((char *)sp->fts_array);
(void)free((char *)sp->fts_path);
/*
* return to original directory, save errno if necessary;
* free up the directory buffer
*/
if (!(sp->fts_options & FTS_NOCHDIR)) {
saved_errno = chdir(sp->fts_wd) ? errno : 0;
(void)free(sp->fts_wd);
}
/* free up the stream pointer */
(void)free((char *)sp);
/* set errno and return */
if (!(sp->fts_options & FTS_NOCHDIR) && saved_errno) {
errno = saved_errno;
return(-1);
}
return(0);
}
FTSENT *
ftsread(sp)
register FTS *sp;
{
register FTSENT *p;
register int instr;
static int cd;
FTSENT *tmp;
char *cp;
/* if finished or unrecoverable error, return NULL */
if (!sp->fts_cur || sp->fts_options & FTS__STOP)
return(NULL);
/* set global stream pointer, and current node pointer */
stream = sp;
p = sp->fts_cur;
/* save and zero out user instructions */
instr = p->fts_instr;
p->fts_instr = 0;
/* if used 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(p, 0);
return(p);
}
if (p->fts_info == FTS_D)
if (instr == FTS_SKIP) {
if (sp->fts_child) {
fts_lfree(sp->fts_child);
sp->fts_child = NULL;
}
} else {
if (!sp->fts_child &&
(!(sp->fts_child = fts_build(sp, 1))))
return(p);
p = sp->fts_child;
sp->fts_child = NULL;
return(sp->fts_cur = p);
}
else if (p->fts_info == FTS_SL && instr == FTS_FOLLOW) {
p->fts_info = fts_stat(p, 1);
return(p);
}
/*
* user may have called ftsset on pointer returned by
* ftschildren; handle it here.
*/
for (p = p->fts_link; p;) {
instr = p->fts_instr;
if (instr == FTS_FOLLOW) {
p->fts_info = fts_stat(p, 1);
p->fts_instr = 0;
break;
}
if (instr == FTS_SKIP) {
tmp = p;
p = p->fts_link;
(void)free((char *)tmp);
continue;
}
p->fts_instr = 0;
break;
}
/* go to next node on this level */
if (p) {
/*
* if root level node, set up paths and return. If not the
* first time, and it's not an absolute pathname, get back
* to wherever we started from.
*/
if (p->fts_level == ROOTLEVEL) {
fts_load(p);
if (cd) {
(void)free((char *)sp->fts_cur);
if (p->fts_path[0] != '/' &&
CHDIR(sp, sp->fts_wd)) {
/* return target path for error msg */
p->fts_path = sp->fts_wd;
p->fts_info = FTS_ERR;
sp->fts_options |= FTS__STOP;
return(sp->fts_cur = p);
}
} else
cd = 1;
p->fts_info = fts_stat(p, 0);
} else {
(void)free((char *)sp->fts_cur);
cp = sp->fts_path + NAPPEND(p->fts_parent);
*cp++ = '/';
bcopy(p->fts_name, cp, p->fts_namelen + 1);
if (p->fts_info == FTS_D && (tmp = fts_cycle(p))) {
sp->fts_savelink = p->fts_link;
p->fts_link = tmp;
}
}
return(sp->fts_cur = p);
}
/* go to parent */
p = sp->fts_cur->fts_parent;
(void)free((char *)sp->fts_cur);
if (p->fts_level == ROOTPARENTLEVEL) {
/*
* done; free everything up and set errno to 0 so the user
* can distinguish between error and EOF.
*/
(void)free((char *)p);
errno = 0;
return(sp->fts_cur = NULL);
}
sp->fts_path[p->fts_pathlen] = '\0';
if (CHDIR(sp, "..")) {
sp->fts_options |= FTS__STOP;
p->fts_info = FTS_ERR;
} else
p->fts_info = FTS_DP;
return(sp->fts_cur = p);
}
/*
* ftsset 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 ftsset. A possible error return is allowed for
* similar reasons.
*/
/* ARGSUSED */
ftsset(sp, p, instr)
FTS *sp;
FTSENT *p;
int instr;
{
p->fts_instr = instr;
return(0);
}
FTSENT *
ftschildren(sp)
register FTS *sp;
{
/*
* set errno to 0 so that user can tell the difference between an
* error and a directory without entries.
*/
errno = 0;
if (sp->fts_cur->fts_info != FTS_D || sp->fts_options & FTS__STOP)
return(NULL);
if (sp->fts_child)
fts_lfree(sp->fts_child);
return(sp->fts_child = fts_build(sp, 0));
}
#define ISDOT(a) (a[0] == '.' && (!a[1] || a[1] == '.' && !a[2]))
static FTSENT *
fts_build(sp, set_node)
register FTS *sp;
int set_node;
{
register struct dirent *dp;
register FTSENT *p, *head;
register int nitems;
DIR *dirp;
int descend, len, level, maxlen, nlinks, saved_errno;
char *cp;
p = sp->fts_cur;
if (!(dirp = opendir(p->fts_accpath))) {
if (set_node) {
errno = 0;
p->fts_info = FTS_DNR;
}
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 =
sp->fts_options & FTS_NOSTAT && sp->fts_options & FTS_PHYSICAL ?
p->fts_statb.st_nlink - (sp->fts_options & FTS_SEEDOT ? 0 : 2) : -1;
if (nlinks || set_node) {
if (FCHDIR(sp, dirfd(dirp))) {
if (set_node) {
errno = 0;
p->fts_info = FTS_DNX;
}
return(NULL);
}
descend = 1;
} else
descend = 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) && !(sp->fts_options & FTS_SEEDOT))
continue;
if (!(p = fts_alloc(dp->d_name, dp->d_namlen))) {
saved_errno = errno;
goto mem1;
}
if (dp->d_namlen > maxlen) {
if (!fts_path((int)dp->d_namlen)) {
/* quit: this stream no longer has a path */
sp->fts_options |= FTS__STOP;
saved_errno = errno;
(void)free((char *)p);
mem1: fts_lfree(head);
if (set_node)
p->fts_info = FTS_ERR;
if (descend && CHDIR(sp, "..")) {
saved_errno = errno;
sp->fts_options |= FTS__STOP;
}
errno = saved_errno;
return(NULL);
}
maxlen = sp->fts_pathlen - sp->fts_cur->fts_pathlen - 1;
}
p->fts_pathlen = len + dp->d_namlen + 1;
p->fts_accpath =
sp->fts_options & 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 (sp->fts_options & FTS_NOCHDIR)
bcopy(p->fts_name, cp, p->fts_namelen + 1);
p->fts_info = fts_stat(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);
if (descend && (!nitems || !set_node) && CHDIR(sp, "..")) {
sp->fts_options |= FTS__STOP;
p->fts_info = FTS_ERR;
*--cp = '\0';
return(NULL);
}
if (!nitems) {
if (set_node)
p->fts_info = FTS_DP;
*--cp = '\0';
return(NULL);
}
if (sp->fts_compar && nitems > 1)
head = fts_sort(head, nitems);
if (set_node)
bcopy(head->fts_name, cp, head->fts_namelen + 1);
else
*--cp = '\0';
return(head);
}
static short
fts_stat(p, symflag)
register FTSENT *p;
int symflag;
{
/*
* detection of symbolic links w/o targets. If FTS_FOLLOW is set,
* the symlink structure is overwritten with the stat structure of
* the target.
*/
if (stream->fts_options & FTS_LOGICAL || symflag) {
if (stat(p->fts_accpath, &p->fts_statb))
return(symflag || !lstat(p->fts_accpath,
&p->fts_statb) ? FTS_SLNONE : FTS_ERR);
} else if (lstat(p->fts_accpath, &p->fts_statb))
return(FTS_ERR);
switch(p->fts_statb.st_mode&S_IFMT) {
case S_IFDIR:
return(FTS_D);
case S_IFLNK:
return(FTS_SL);
case S_IFREG:
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((char *)ptr, (u_int)((nelem) * sizeof(type)))
static FTSENT *
fts_sort(head, nitems)
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 > stream->fts_nitems) {
stream->fts_nitems = nitems + 40;
if (!(stream->fts_array =
R(FTSENT *, stream->fts_nitems, stream->fts_array))) {
stream->fts_nitems = 0;
return(head);
}
}
for (ap = stream->fts_array, p = head; p; p = p->fts_link)
*ap++ = p;
qsort((char *)stream->fts_array, nitems, sizeof(FTSENT *),
stream->fts_compar);
for (head = *(ap = stream->fts_array); --nitems; ++ap)
ap[0]->fts_link = ap[1];
ap[0]->fts_link = NULL;
return(head);
}
static FTSENT *
fts_alloc(name, len)
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((u_int)(sizeof(FTSENT) + len))))
return(NULL);
bcopy(name, p->fts_name, len + 1);
p->fts_namelen = len;
p->fts_path = stream->fts_path;
p->fts_instr = 0;
p->fts_local.number = 0;
p->fts_local.pointer = NULL;
return(p);
}
static
fts_lfree(head)
register FTSENT *head;
{
register FTSENT *p;
while (p = head) {
head = head->fts_link;
(void)free((char *)p);
}
}
/*
* allow essentially unlimited paths; certain programs (find, remove, 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
fts_path(size)
int size;
{
stream->fts_pathlen += size + 128;
return((int)(stream->fts_path =
R(char, stream->fts_pathlen, stream->fts_path)));
}
static FTSENT *
fts_root(name)
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(name, cp - name));
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.