Make cp and mv optionally preserve hard links.

coreutils/du.c

@@ -59,78 +59,6 @@ static void print_summary(long size, char *filename)
 	}
 }
 
-#define HASH_SIZE       311             /* Should be prime */
-#define hash_inode(i)   ((i) % HASH_SIZE)
-
-typedef struct ino_dev_hash_bucket_struct {
-  struct ino_dev_hash_bucket_struct *next;
-  ino_t ino;
-  dev_t dev;
-  char name[1];
-} ino_dev_hashtable_bucket_t;
-
-static ino_dev_hashtable_bucket_t *ino_dev_hashtable[HASH_SIZE];
-
-/*
- * Return 1 if statbuf->st_ino && statbuf->st_dev are recorded in
- * `ino_dev_hashtable', else return 0
- *
- * If NAME is a non-NULL pointer to a character pointer, and there is
- * a match, then set *NAME to the value of the name slot in that
- * bucket.
- */
-static int is_in_ino_dev_hashtable(const struct stat *statbuf, char **name)
-{
-	ino_dev_hashtable_bucket_t *bucket;
-
-	bucket = ino_dev_hashtable[hash_inode(statbuf->st_ino)];
-	while (bucket != NULL) {
-	  if ((bucket->ino == statbuf->st_ino) &&
-		  (bucket->dev == statbuf->st_dev))
-	  {
-		if (name) *name = bucket->name;
-		return 1;
-	  }
-	  bucket = bucket->next;
-	}
-	return 0;
-}
-
-/* Add statbuf to statbuf hash table */
-static void add_to_ino_dev_hashtable(const struct stat *statbuf, const char *name)
-{
-	int i;
-	size_t s;
-	ino_dev_hashtable_bucket_t *bucket;
-
-	i = hash_inode(statbuf->st_ino);
-	s = name ? strlen(name) : 0;
-	bucket = xmalloc(sizeof(ino_dev_hashtable_bucket_t) + s);
-	bucket->ino = statbuf->st_ino;
-	bucket->dev = statbuf->st_dev;
-	if (name)
-		strcpy(bucket->name, name);
-	else
-		bucket->name[0] = '\0';
-	bucket->next = ino_dev_hashtable[i];
-	ino_dev_hashtable[i] = bucket;
-}
-
-/* Clear statbuf hash table */
-static void reset_ino_dev_hashtable(void)
-{
-	int i;
-	ino_dev_hashtable_bucket_t *bucket;
-
-	for (i = 0; i < HASH_SIZE; i++) {
-		while (ino_dev_hashtable[i] != NULL) {
-			bucket = ino_dev_hashtable[i]->next;
-			free(ino_dev_hashtable[i]);
-			ino_dev_hashtable[i] = bucket;
-		}
-	}
-}
-
 /* tiny recursive du */
 static long du(char *filename)
 {
@@ -246,7 +174,7 @@ int du_main(int argc, char **argv)
 	return status;
 }
 
-/* $Id: du.c,v 1.51 2001/10/24 04:59:27 andersen Exp $ */
+/* $Id: du.c,v 1.52 2001/12/17 15:26:25 kraai Exp $ */
 /*
 Local Variables:
 c-file-style: "linux"

include/libbb.h

@@ -286,4 +286,8 @@ extern const char * const can_not_create_raw_socket;
 #define CURRENT_TTY "/dev/tty"
 #define CONSOLE_DEV "/dev/console"
 
+int is_in_ino_dev_hashtable(const struct stat *statbuf, char **name);
+void add_to_ino_dev_hashtable(const struct stat *statbuf, const char *name);
+void reset_ino_dev_hashtable(void);
+
 #endif /* __LIBCONFIG_H__ */

libbb/Makefile

@@ -45,7 +45,7 @@ obj-y += ask_confirmation.o chomp.o concat_path_file.o copy_file.o \
 	xgetcwd.o xreadlink.o xregcomp.o interface.o remove_file.o last_char_is.o \
 	copyfd.o vherror_msg.o herror_msg.o herror_msg_and_die.o xgethostbyname.o \
 	dirname.o make_directory.o create_icmp_socket.o u_signal_names.o arith.o \
-	simplify_path.o inet_common.o $(LIBBB_MOBJS) $(LIBBB_AROBJS)
+	simplify_path.o inet_common.o inode_hash.o $(LIBBB_MOBJS) $(LIBBB_AROBJS)
 
 
 # Hand off to toplevel Rules.mak

libbb/copy_file.c

@@ -30,7 +30,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "libbb.h"
+#include "busybox.h"
 
 int copy_file(const char *source, const char *dest, int flags)
 {
@@ -131,6 +131,19 @@ int copy_file(const char *source, const char *dest, int flags)
 		}
 	} else if (S_ISREG(source_stat.st_mode)) {
 		FILE *sfp, *dfp=NULL;
+#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS
+		char *link_name;
+
+		if (!(flags & FILEUTILS_DEREFERENCE) &&
+				is_in_ino_dev_hashtable(&source_stat, &link_name)) {
+			if (link(link_name, dest) < 0) {
+				perror_msg("unable to link `%s'", dest);
+				return -1;
+			}
+
+			return 0;
+		}
+#endif
 
 		if ((sfp = fopen(source, "r")) == NULL) {
 			perror_msg("unable to open `%s'", source);
@@ -212,12 +225,21 @@ int copy_file(const char *source, const char *dest, int flags)
 			if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
 				perror_msg("unable to preserve ownership of `%s'", dest);
 #endif
+
+#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS
+		add_to_ino_dev_hashtable(&source_stat, dest);
+#endif
+
 		return 0;
 	} else {
 		error_msg("internal error: unrecognized file type");
 		return -1;
 	}
 
+#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS
+	add_to_ino_dev_hashtable(&source_stat, dest);
+#endif
+
 end:
 
 	if (flags & FILEUTILS_PRESERVE_STATUS) {

libbb/inode_hash.c

@@ -29,6 +29,13 @@
 #define HASH_SIZE	311		/* Should be prime */
 #define hash_inode(i)	((i) % HASH_SIZE)
 
+typedef struct ino_dev_hash_bucket_struct {
+  struct ino_dev_hash_bucket_struct *next;
+  ino_t ino;
+  dev_t dev;
+  char name[1];
+} ino_dev_hashtable_bucket_t;
+
 static ino_dev_hashtable_bucket_t *ino_dev_hashtable[HASH_SIZE];
 
 /*

testsuite/cp/cp-preserves-hard-links

@@ -0,0 +1,6 @@
+# UNSUPPORTED: CONFIG_FEATURE_PRESERVE_HARDLINKS
+touch foo
+ln foo bar
+mkdir baz
+busybox cp -d foo bar baz
+test baz/foo -ef baz/bar