-/* vi: set sw=4 ts=4 :*/
/* dirtree.c - Functions for dealing with directory trees.
*
* Copyright 2007 Rob Landley <rob@landley.net>
#include "toys.h"
-// NOTE: This uses toybuf. Possibly it shouldn't do that.
+int isdotdot(char *name)
+{
+ if (name[0]=='.' && (!name[1] || (name[1]=='.' && !name[2]))) return 1;
+
+ return 0;
+}
+
+// Default callback, filters out "." and ".." except at top level.
+
+int dirtree_notdotdot(struct dirtree *catch)
+{
+ // Should we skip "." and ".."?
+ return (!catch->parent||!isdotdot(catch->name))
+ *(DIRTREE_SAVE|DIRTREE_RECURSE);
+}
+
+// Create a dirtree node from a path, with stat and symlink info.
+// (This doesn't open directory filehandles yet so as not to exhaust the
+// filehandle space on large trees, dirtree_handle_callback() does that.)
+
+struct dirtree *dirtree_add_node(struct dirtree *parent, char *name, int flags)
+{
+ struct dirtree *dt = NULL;
+ struct stat st;
+ int len = 0, linklen = 0;
+
+ if (name) {
+ // open code this because haven't got node to call dirtree_parentfd() on yet
+ int fd = parent ? parent->dirfd : AT_FDCWD;
+
+ if (fstatat(fd, name, &st, AT_SYMLINK_NOFOLLOW*!(flags&DIRTREE_SYMFOLLOW)))
+ goto error;
+ if (S_ISLNK(st.st_mode)) {
+ if (0>(linklen = readlinkat(fd, name, libbuf, 4095))) goto error;
+ libbuf[linklen++]=0;
+ }
+ len = strlen(name);
+ }
+ dt = xzalloc((len = sizeof(struct dirtree)+len+1)+linklen);
+ dt->parent = parent;
+ if (name) {
+ memcpy(&(dt->st), &st, sizeof(struct stat));
+ strcpy(dt->name, name);
+
+ if (linklen) dt->symlink = memcpy(len+(char *)dt, libbuf, linklen);
+ }
+
+ return dt;
+
+error:
+ if (!(flags&DIRTREE_SHUTUP) && !isdotdot(name)) {
+ char *path = parent ? dirtree_path(parent, 0) : "";
+
+ perror_msg("%s%s%s", path, parent ? "/" : "", name);
+ if (parent) free(path);
+ }
+ if (parent) parent->symlink = (char *)1;
+ free(dt);
+ return 0;
+}
+
+// Return path to this node, assembled recursively.
+
+// Initial call can pass in NULL to plen, or point to an int initialized to 0
+// to return the length of the path, or a value greater than 0 to allocate
+// extra space if you want to append your own text to the string.
+
+char *dirtree_path(struct dirtree *node, int *plen)
+{
+ char *path;
+ int len;
+
+ if (!node) {
+ path = xmalloc(*plen);
+ *plen = 0;
+ return path;
+ }
+
+ len = (plen ? *plen : 0)+strlen(node->name)+1;
+ path = dirtree_path(node->parent, &len);
+ if (len && path[len-1] != '/') path[len++]='/';
+ len = (stpcpy(path+len, node->name) - path);
+ if (plen) *plen = len;
+
+ return path;
+}
-// Create a dirtree node from a path.
+int dirtree_parentfd(struct dirtree *node)
+{
+ return node->parent ? node->parent->dirfd : AT_FDCWD;
+}
-struct dirtree *dirtree_add_node(char *path)
+// Handle callback for a node in the tree. Returns saved node(s) if
+// callback returns DIRTREE_SAVE, otherwise frees consumed nodes and
+// returns NULL. If !callback return top node unchanged.
+// If !new return DIRTREE_ABORTVAL
+
+struct dirtree *dirtree_handle_callback(struct dirtree *new,
+ int (*callback)(struct dirtree *node))
{
- struct dirtree *dt;
- char *name;
-
- // Find last chunk of name.
-
- for (;;) {
- name = strrchr(path, '/');
-
- if (!name) name = path;
- else {
- if (*(name+1)) name++;
- else {
- *name=0;
- continue;
- }
- }
- break;
- }
-
- dt = xzalloc(sizeof(struct dirtree)+strlen(name)+1);
- if (lstat(path, &(dt->st))) {
- error_msg("Skipped '%s'",name);
- free(dt);
- return 0;
- }
- strcpy(dt->name, name);
-
- return dt;
+ int flags;
+
+ if (!new) return DIRTREE_ABORTVAL;
+ if (!callback) return new;
+ flags = callback(new);
+
+ if (S_ISDIR(new->st.st_mode) && (flags & (DIRTREE_RECURSE|DIRTREE_COMEAGAIN)))
+ flags = dirtree_recurse(new, callback,
+ openat(dirtree_parentfd(new), new->name, O_CLOEXEC), flags);
+
+ // If this had children, it was callback's job to free them already.
+ if (!(flags & DIRTREE_SAVE)) {
+ free(new);
+ new = NULL;
+ }
+
+ return (flags & DIRTREE_ABORT)==DIRTREE_ABORT ? DIRTREE_ABORTVAL : new;
}
-// Given a directory (in a writeable PATH_MAX buffer), recursively read in a
-// directory tree.
-//
-// If callback==NULL, allocate tree of struct dirtree and
-// return root of tree. Otherwise call callback(node) on each hit, free
-// structures after use, and return NULL.
+// Recursively read/process children of directory node, filtering through
+// callback(). Uses and closes supplied ->dirfd.
-struct dirtree *dirtree_read(char *path, struct dirtree *parent,
- int (*callback)(struct dirtree *node))
+int dirtree_recurse(struct dirtree *node,
+ int (*callback)(struct dirtree *node), int dirfd, int flags)
{
- struct dirtree *dt = NULL, **ddt = &dt;
- DIR *dir;
- int len = strlen(path);
-
- if (!(dir = opendir(path))) perror_msg("No %s", path);
-
- for (;;) {
- struct dirent *entry = readdir(dir);
- if (!entry) break;
-
- // Skip "." and ".."
- if (entry->d_name[0]=='.') {
- if (!entry->d_name[1]) continue;
- if (entry->d_name[1]=='.' && !entry->d_name[2]) continue;
- }
-
- snprintf(path+len, sizeof(toybuf)-len, "/%s", entry->d_name);
- *ddt = dirtree_add_node(path);
- if (!*ddt) continue;
- (*ddt)->parent = parent;
- if (callback) callback(*ddt);
- if (entry->d_type == DT_DIR)
- (*ddt)->child = dirtree_read(path, *ddt, callback);
- if (callback) free(*ddt);
- else ddt = &((*ddt)->next);
- path[len]=0;
- }
-
- return dt;
+ struct dirtree *new, **ddt = &(node->child);
+ struct dirent *entry;
+ DIR *dir;
+
+ node->dirfd = dirfd;
+ if (node->dirfd == -1 || !(dir = fdopendir(node->dirfd))) {
+ if (!(flags & DIRTREE_SHUTUP)) {
+ char *path = dirtree_path(node, 0);
+ perror_msg("No %s", path);
+ free(path);
+ }
+ close(node->dirfd);
+
+ return flags;
+ }
+
+ // according to the fddir() man page, the filehandle in the DIR * can still
+ // be externally used by things that don't lseek() it.
+
+ // The extra parentheses are to shut the stupid compiler up.
+ while ((entry = readdir(dir))) {
+ if ((flags&DIRTREE_PROC) && !isdigit(*entry->d_name)) continue;
+ if (!(new = dirtree_add_node(node, entry->d_name, flags))) continue;
+ new = dirtree_handle_callback(new, callback);
+ if (new == DIRTREE_ABORTVAL) break;
+ if (new) {
+ *ddt = new;
+ ddt = &((*ddt)->next);
+ }
+ }
+
+ if (flags & DIRTREE_COMEAGAIN) {
+ node->again++;
+ flags = callback(node);
+ }
+
+ // This closes filehandle as well, so note it
+ closedir(dir);
+ node->dirfd = -1;
+
+ return flags;
}
+// Create dirtree from path, using callback to filter nodes. If !callback
+// return just the top node. Use dirtree_notdotdot callback to allocate a
+// tree of struct dirtree nodes and return pointer to root node for later
+// processing.
+// Returns DIRTREE_ABORTVAL if path didn't exist (use DIRTREE_SHUTUP to handle
+// error message yourself).
+struct dirtree *dirtree_flagread(char *path, int flags,
+ int (*callback)(struct dirtree *node))
+{
+ return dirtree_handle_callback(dirtree_add_node(0, path, flags), callback);
+}
+
+// Common case
+struct dirtree *dirtree_read(char *path, int (*callback)(struct dirtree *node))
+{
+ return dirtree_flagread(path, 0, callback);
+}
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