1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10#include "libbb.h"
11
12#undef DEBUG_RECURS_ACTION
13
14/*
15 * Walk down all the directories under the specified
16 * location, and do something (something specified
17 * by the fileAction and dirAction function pointers).
18 *
19 * Unfortunately, while nftw(3) could replace this and reduce
20 * code size a bit, nftw() wasn't supported before GNU libc 2.1,
21 * and so isn't sufficiently portable to take over since glibc2.1
22 * is so stinking huge.
23 */
24
25static int FAST_FUNC true_action(const char *fileName UNUSED_PARAM,
26		struct stat *statbuf UNUSED_PARAM,
27		void* userData UNUSED_PARAM,
28		int depth UNUSED_PARAM)
29{
30	return TRUE;
31}
32
33/* fileAction return value of 0 on any file in directory will make
34 * recursive_action() return 0, but it doesn't stop directory traversal
35 * (fileAction/dirAction will be called on each file).
36 *
37 * If !ACTION_RECURSE, dirAction is called on the directory and its
38 * return value is returned from recursive_action(). No recursion.
39 *
40 * If ACTION_RECURSE, recursive_action() is called on each directory.
41 * If any one of these calls returns 0, current recursive_action() returns 0.
42 *
43 * If ACTION_DEPTHFIRST, dirAction is called after recurse.
44 * If it returns 0, the warning is printed and recursive_action() returns 0.
45 *
46 * If !ACTION_DEPTHFIRST, dirAction is called before we recurse.
47 * Return value of 0 (FALSE) or 2 (SKIP) prevents recursion
48 * into that directory, instead recursive_action() returns 0 (if FALSE)
49 * or 1 (if SKIP)
50 *
51 * ACTION_FOLLOWLINKS mainly controls handling of links to dirs.
52 * 0: lstat(statbuf). Calls fileAction on link name even if points to dir.
53 * 1: stat(statbuf). Calls dirAction and optionally recurse on link to dir.
54 */
55
56int FAST_FUNC recursive_action(const char *fileName,
57		unsigned flags,
58		int FAST_FUNC (*fileAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
59		int FAST_FUNC (*dirAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
60		void* userData,
61		unsigned depth)
62{
63	struct stat statbuf;
64	unsigned follow;
65	int status;
66	DIR *dir;
67	struct dirent *next;
68
69	if (!fileAction) fileAction = true_action;
70	if (!dirAction) dirAction = true_action;
71
72	follow = ACTION_FOLLOWLINKS;
73	if (depth == 0)
74		follow = ACTION_FOLLOWLINKS | ACTION_FOLLOWLINKS_L0;
75	follow &= flags;
76	status = (follow ? stat : lstat)(fileName, &statbuf);
77	if (status < 0) {
78#ifdef DEBUG_RECURS_ACTION
79		bb_error_msg("status=%d flags=%x", status, flags);
80#endif
81		if ((flags & ACTION_DANGLING_OK)
82		 && errno == ENOENT
83		 && lstat(fileName, &statbuf) == 0
84		) {
85			/* Dangling link */
86			return fileAction(fileName, &statbuf, userData, depth);
87		}
88		goto done_nak_warn;
89	}
90
91	/* If S_ISLNK(m), then we know that !S_ISDIR(m).
92	 * Then we can skip checking first part: if it is true, then
93	 * (!dir) is also true! */
94	if ( /* (!(flags & ACTION_FOLLOWLINKS) && S_ISLNK(statbuf.st_mode)) || */
95	 !S_ISDIR(statbuf.st_mode)
96	) {
97		return fileAction(fileName, &statbuf, userData, depth);
98	}
99
100	/* It's a directory (or a link to one, and followLinks is set) */
101
102	if (!(flags & ACTION_RECURSE)) {
103		return dirAction(fileName, &statbuf, userData, depth);
104	}
105
106	if (!(flags & ACTION_DEPTHFIRST)) {
107		status = dirAction(fileName, &statbuf, userData, depth);
108		if (!status)
109			goto done_nak_warn;
110		if (status == SKIP)
111			return TRUE;
112	}
113
114	dir = opendir(fileName);
115	if (!dir) {
116		/* findutils-4.1.20 reports this */
117		/* (i.e. it doesn't silently return with exit code 1) */
118		/* To trigger: "find -exec rm -rf {} \;" */
119		goto done_nak_warn;
120	}
121	status = TRUE;
122	while ((next = readdir(dir)) != NULL) {
123		char *nextFile;
124
125		nextFile = concat_subpath_file(fileName, next->d_name);
126		if (nextFile == NULL)
127			continue;
128		/* process every file (NB: ACTION_RECURSE is set in flags) */
129		if (!recursive_action(nextFile, flags, fileAction, dirAction,
130						userData, depth + 1))
131			status = FALSE;
132//		s = recursive_action(nextFile, flags, fileAction, dirAction,
133//						userData, depth + 1);
134		free(nextFile);
135//#define RECURSE_RESULT_ABORT 3
136//		if (s == RECURSE_RESULT_ABORT) {
137//			closedir(dir);
138//			return s;
139//		}
140//		if (s == FALSE)
141//			status = FALSE;
142	}
143	closedir(dir);
144
145	if (flags & ACTION_DEPTHFIRST) {
146		if (!dirAction(fileName, &statbuf, userData, depth))
147			goto done_nak_warn;
148	}
149
150	return status;
151
152 done_nak_warn:
153	if (!(flags & ACTION_QUIET))
154		bb_simple_perror_msg(fileName);
155	return FALSE;
156}
157