Make cp and mv optionally preserve hard links.

6 files changed, 42 insertions, 75 deletions

diff --git a/coreutils/du.c b/coreutils/du.c
index c378837d0..e34a7f46f 100644
--- a/coreutils/du.c
+++ b/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"
diff --git a/include/libbb.h b/include/libbb.h
index a953b3cb0..fccdf5fdf 100644
--- a/include/libbb.h
+++ b/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__ */
diff --git a/libbb/Makefile b/libbb/Makefile
index ef8fef4b7..879be2452 100644
--- a/libbb/Makefile
+++ b/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
diff --git a/libbb/copy_file.c b/libbb/copy_file.c
index 29778f2a4..ea05c9b8e 100644
--- a/libbb/copy_file.c
+++ b/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) {
diff --git a/libbb/inode_hash.c b/libbb/inode_hash.c
index 52c54cdc1..36484e6ae 100644
--- a/libbb/inode_hash.c
+++ b/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];
 
 /*
diff --git a/testsuite/cp/cp-preserves-hard-links b/testsuite/cp/cp-preserves-hard-links
new file mode 100644
index 000000000..c17f42635
--- /dev/null
+++ b/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