add recursive_action() and concat_subpath_file() from busybox

include/libbb.h

@@ -1,9 +1,27 @@
 
 #ifndef __LIBBB_H
 #define __LIBBB_H
+
+#include <linux/stat.h>
+
+#define DOT_OR_DOTDOT(s) ((s)[0] == '.' && (!(s)[1] || ((s)[1] == '.' && !(s)[2])))
+
 char *concat_path_file(const char *path, const char *filename);
+char *concat_subpath_file(const char *path, const char *f);
 int execable_file(const char *name);
 char *find_execable(const char *filename);
 char* last_char_is(const char *s, int c);
 
+enum {
+	ACTION_RECURSE     = (1 << 0),
+	/* ACTION_FOLLOWLINKS = (1 << 1), - unused */
+	ACTION_DEPTHFIRST  = (1 << 2),
+	/*ACTION_REVERSE   = (1 << 3), - unused */
+};
+
+int recursive_action(const char *fileName, unsigned flags,
+	int (*fileAction) (const char *fileName, struct stat* statbuf, void* userData, int depth),
+	int (*dirAction) (const char *fileName, struct stat* statbuf, void* userData, int depth),
+	void* userData, const unsigned depth);
+
 #endif /* __LIBBB_H */

lib/Makefile

@@ -12,6 +12,8 @@ obj-y			+= getopt.o
 obj-y 			+= readkey.o
 obj-y			+= kfifo.o
 obj-y			+= libbb.o
+obj-y			+= libgen.o
+obj-y			+= recursive_action.o
 obj-$(CONFIG_BZLIB)	+= bzlib.o bzlib_crctable.o bzlib_decompress.o bzlib_huffman.o bzlib_randtable.o
 obj-$(CONFIG_ZLIB)	+= zlib.o gunzip.o
 obj-$(CONFIG_CRC32)	+= crc32.o

lib/libbb.c

@@ -35,6 +35,19 @@ char *concat_path_file(const char *path, const char *filename)
 	return str;
 }
 
+/*
+ * This function make special for recursive actions with usage
+ * concat_path_file(path, filename)
+ * and skipping "." and ".." directory entries
+ */
+
+char *concat_subpath_file(const char *path, const char *f)
+{
+	if (f && DOT_OR_DOTDOT(f))
+		return NULL;
+	return concat_path_file(path, f);
+}
+
 /* check if path points to an executable file;
  * return 1 if found;
  * return 0 otherwise;
@@ -85,3 +98,4 @@ char* last_char_is(const char *s, int c)
 	}
 	return NULL;
 }
+

lib/recursive_action.c

@@ -0,0 +1,130 @@
+/* vi: set sw=8 ts=8: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+#ifdef __U_BOOT__
+
+#include <common.h>
+#include <fs.h>
+#include <linux/stat.h>
+#include <malloc.h>
+#include <libbb.h>
+
+#endif
+
+/*
+ * Walk down all the directories under the specified
+ * location, and do something (something specified
+ * by the fileAction and dirAction function pointers).
+ *
+ * Unfortunately, while nftw(3) could replace this and reduce
+ * code size a bit, nftw() wasn't supported before GNU libc 2.1,
+ * and so isn't sufficiently portable to take over since glibc2.1
+ * is so stinking huge.
+ */
+
+static int true_action(const char *fileName, struct stat *statbuf,
+						void* userData, int depth)
+{
+	return 1;
+}
+
+/* fileAction return value of 0 on any file in directory will make
+ * recursive_action() return 0, but it doesn't stop directory traversal
+ * (fileAction/dirAction will be called on each file).
+ *
+ * if !depthFirst, dirAction return value of 0 (FALSE) or 2 (SKIP)
+ * prevents recursion into that directory, instead
+ * recursive_action() returns 0 (if FALSE) or 1 (if SKIP).
+ *
+ * followLinks=0/1 differs mainly in handling of links to dirs.
+ * 0: lstat(statbuf). Calls fileAction on link name even if points to dir.
+ * 1: stat(statbuf). Calls dirAction and optionally recurse on link to dir.
+ */
+
+int recursive_action(const char *fileName,
+		unsigned flags,
+		int (*fileAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
+		int (*dirAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
+		void* userData,
+		const unsigned depth)
+{
+	struct stat statbuf;
+	int status;
+	DIR *dir;
+	struct dirent *next;
+
+	if (!fileAction) fileAction = true_action;
+	if (!dirAction) dirAction = true_action;
+	status = stat(fileName, &statbuf);
+
+	if (status < 0) {
+#ifdef DEBUG_RECURS_ACTION
+		bb_error_msg("status=%d followLinks=%d TRUE=%d",
+				status, flags & ACTION_FOLLOWLINKS, TRUE);
+#endif
+		goto done_nak_warn;
+	}
+
+	/* If S_ISLNK(m), then we know that !S_ISDIR(m).
+	 * Then we can skip checking first part: if it is true, then
+	 * (!dir) is also true! */
+	if ( /* (!(flags & ACTION_FOLLOWLINKS) && S_ISLNK(statbuf.st_mode)) || */
+	 !S_ISDIR(statbuf.st_mode)
+	) {
+		return fileAction(fileName, &statbuf, userData, depth);
+	}
+
+	/* It's a directory (or a link to one, and followLinks is set) */
+
+	if (!(flags & ACTION_RECURSE)) {
+		return dirAction(fileName, &statbuf, userData, depth);
+	}
+
+	if (!(flags & ACTION_DEPTHFIRST)) {
+		status = dirAction(fileName, &statbuf, userData, depth);
+		if (!status) {
+			goto done_nak_warn;
+		}
+		if (status == 2)
+			return 1;
+	}
+
+	dir = opendir(fileName);
+	if (!dir) {
+		/* findutils-4.1.20 reports this */
+		/* (i.e. it doesn't silently return with exit code 1) */
+		/* To trigger: "find -exec rm -rf {} \;" */
+		goto done_nak_warn;
+	}
+	status = 1;
+	while ((next = readdir(dir)) != NULL) {
+		char *nextFile;
+
+		nextFile = concat_subpath_file(fileName, next->d_name);
+		if (nextFile == NULL)
+			continue;
+		/* now descend into it, forcing recursion. */
+		if (!recursive_action(nextFile, flags | ACTION_RECURSE,
+				fileAction, dirAction, userData, depth+1)) {
+			status = 0;
+		}
+		free(nextFile);
+	}
+	closedir(dir);
+	if ((flags & ACTION_DEPTHFIRST) &&
+		!dirAction(fileName, &statbuf, userData, depth)) {
+			goto done_nak_warn;
+	}
+
+	if (!status)
+		return 0;
+	return 1;
+done_nak_warn:
+	printf("%s", fileName);
+	return 0;
+}