1 files changed, 126 insertions, 0 deletions
diff --git a/libbb/recursive_action.c b/libbb/recursive_action.c
new file mode 100644
index 000000000..121a3dffd
--- /dev/null
+++ b/libbb/recursive_action.c
@@ -0,0 +1,126 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * 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.
+ */
+
+#include "libbb.h"
+
+#undef DEBUG_RECURS_ACTION
+
+/*
+ * 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 TRUE;
+}
+
+/* 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,
+		int recurse, int followLinks, int depthFirst,
+		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,
+		int depth)
+{
+	struct stat statbuf;
+	int status;
+	DIR *dir;
+	struct dirent *next;
+
+	if (!fileAction) fileAction = true_action;
+	if (!dirAction) dirAction = true_action;
+
+	status = (followLinks ? stat : lstat)(fileName, &statbuf);
+
+	if (status < 0) {
+#ifdef DEBUG_RECURS_ACTION
+		bb_error_msg("status=%d followLinks=%d TRUE=%d",
+				status, followLinks, TRUE);
+#endif
+		bb_perror_msg("%s", fileName);
+		return FALSE;
+	}
+
+	/* 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 ( /* (!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 (!recurse) {
+		return dirAction(fileName, &statbuf, userData, depth);
+	}
+
+	if (!depthFirst) {
+		status = dirAction(fileName, &statbuf, userData, depth);
+		if (!status) {
+			bb_perror_msg("%s", fileName);
+			return FALSE;
+		}
+		if (status == SKIP)
+			return TRUE;
+	}
+
+	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 {} \;" */
+		bb_perror_msg("%s", fileName);
+		return FALSE;
+	}
+	status = TRUE;
+	while ((next = readdir(dir)) != NULL) {
+		char *nextFile;
+
+		nextFile = concat_subpath_file(fileName, next->d_name);
+		if (nextFile == NULL)
+			continue;
+		if (!recursive_action(nextFile, TRUE, followLinks, depthFirst,
+				fileAction, dirAction, userData, depth+1)) {
+			status = FALSE;
+		}
+		free(nextFile);
+	}
+	closedir(dir);
+	if (depthFirst) {
+		if (!dirAction(fileName, &statbuf, userData, depth)) {
+			bb_perror_msg("%s", fileName);
+			return FALSE;
+		}
+	}
+
+	if (!status)
+		return FALSE;
+	return TRUE;
+}