added --backup-dir option from Bob Edwards

this is very useful for incremental backups

backup.c

@@ -22,9 +22,11 @@
 
 extern int verbose;
 extern char *backup_suffix;
+extern char *backup_dir;
 
 
-int make_backup(char *fname)
+/* simple backup creates a backup with a suffix in the same directory */
+static int make_simple_backup(char *fname)
 {
 	char fnamebak[MAXPATHLEN];
 	if (strlen(fname) + strlen(backup_suffix) > (MAXPATHLEN-1)) {
@@ -44,3 +46,134 @@ int make_backup(char *fname)
 	}
 	return 1;
 }
+
+
+/* recursively make a directory path */
+static int make_dir(char *name, int mask)
+{
+	char newdir [MAXPATHLEN];
+	char *p, *d;
+
+	/* copy pathname over, look for last '/' */
+	for (p = d = newdir; *name; *d++ = *name++)
+		if (*name == '/')
+			p = d;
+	if (p == newdir)
+		return 0;
+	*p = 0;
+
+	/* make the new directory, if that fails then make its parent */
+	while (do_mkdir (newdir, mask) != 0)
+		if ((errno != ENOENT) || !make_dir (newdir, mask))
+			return 0;
+
+	return 1;
+} /* make_dir */
+
+
+/* robustly move a file, creating new directory structures if necessary */
+static int robust_move(char *src, char *dst)
+{
+	int keep_trying = 4;
+	int keep_path_extfs = 0;
+	int failed;
+
+	while (keep_trying) {
+		if (keep_path_extfs)
+			failed = copy_file (src, dst, 0755);
+		else
+			failed = robust_rename (src, dst);
+
+		if (failed) {
+			if (verbose > 2)
+				rprintf (FERROR, "robust_move failed: %s(%d)\n",
+					strerror (errno), errno);
+			switch (errno) {
+				/* external filesystem */
+				case EXDEV:
+					keep_path_extfs = 1;
+					keep_trying--;
+					break;
+				/* no directory to write to */
+				case ENOENT:
+					make_dir (dst, 0755);
+					keep_trying--;
+					break;
+				default:
+					keep_trying = 0;
+			} /* switch */
+		} else
+			keep_trying = 0;
+	} /* while */
+	return (!failed);
+} /* robust_move */
+
+
+/* if we have a backup_dir, then we get here from make_backup().
+   We will move the file to be deleted into a parallel directory tree */
+static int keep_backup(char *fname)
+{
+	static int initialised;
+
+	char keep_name [MAXPATHLEN];
+	STRUCT_STAT st;
+	struct file_struct *file;
+
+	if (!initialised) {
+		if (backup_dir[strlen(backup_dir) - 1] == '/')
+			backup_dir[strlen(backup_dir) - 1] = 0;
+		if (verbose > 0)
+			rprintf (FINFO, "backup_dir is %s\n", backup_dir);
+		initialised = 1;
+	}
+
+	/* return if no file to keep */
+#if SUPPORT_LINKS
+	if (do_lstat (fname, &st)) return 1;
+#else
+	if (do_stat (fname, &st)) return 1;
+#endif
+
+	file = make_file (0, fname);
+
+	/* make a complete pathname for backup file */
+	if (strlen(backup_dir) + strlen(fname) > (MAXPATHLEN - 1)) {
+		rprintf (FERROR, "keep_backup filename too long\n");
+		return 0;
+	}
+	slprintf(keep_name, sizeof (keep_name), "%s/%s", backup_dir, fname);
+
+	if (!S_ISDIR(file->mode)) {
+	/* move to keep tree if a file */
+		if (!robust_move (fname, keep_name))
+			rprintf(FERROR, "keep_backup failed %s -> %s : %s\n",
+				fname, keep_name, strerror(errno));
+	} else {
+	/* this bit only used to "keep" empty directories */
+		/* make the parent directories */
+		make_dir (keep_name, 0755);
+		/* now make the (empty) directory */
+		do_mkdir (keep_name, file->mode);
+		if (verbose > 1)
+			rprintf (FINFO, "keep_backup: made empty dir: %s\n",
+				keep_name);
+	}
+
+	set_perms (keep_name, file, NULL, 0);
+	free_file (file);
+	free (file);
+	if (verbose > 1)
+		rprintf (FINFO, "keep_backup %s -> %s\n", fname, keep_name);
+	return 1;
+} /* keep_backup */
+
+
+/* main backup switch routine */
+int make_backup(char *fname)
+{
+	if (backup_dir)
+		return (keep_backup(fname));
+	else
+		return (make_simple_backup(fname));
+}
+

flist.c

@@ -409,7 +409,8 @@ static int skip_filesystem(char *fname, STRUCT_STAT *st)
 	return (st2.st_dev != filesystem_dev);
 }
 
-static struct file_struct *make_file(int f, char *fname)
+/* create a file_struct for a named file */
+struct file_struct *make_file(int f, char *fname)
 {
 	struct file_struct *file;
 	STRUCT_STAT st;
@@ -921,7 +922,7 @@ int flist_find(struct file_list *flist,struct file_struct *f)
 /*
  * free up one file
  */
-static void free_file(struct file_struct *file)
+void free_file(struct file_struct *file)
 {
 	if (!file) return;
 	if (file->basename) free(file->basename);

options.c

@@ -74,6 +74,7 @@ char *shell_cmd = NULL;
 char *log_format = NULL;
 char *password_file = NULL;
 char *rsync_path = RSYNC_NAME;
+char *backup_dir = NULL;
 int rsync_port = RSYNC_PORT;
 
 int verbose = 0;
@@ -107,6 +108,7 @@ void usage(int F)
   rprintf(F," -r, --recursive             recurse into directories\n");
   rprintf(F," -R, --relative              use relative path names\n");
   rprintf(F," -b, --backup                make backups (default %s suffix)\n",BACKUP_SUFFIX);
+  rprintf(F,"     --backup-dir            make backups into this directory");
   rprintf(F,"     --suffix=SUFFIX         override backup suffix\n");  
   rprintf(F," -u, --update                update only (don't overwrite newer files)\n");
   rprintf(F," -l, --links                 preserve soft links\n");
@@ -169,7 +171,7 @@ enum {OPT_VERSION, OPT_SUFFIX, OPT_SENDER, OPT_SERVER, OPT_EXCLUDE,
       OPT_INCLUDE, OPT_INCLUDE_FROM, OPT_STATS, OPT_PARTIAL, OPT_PROGRESS,
       OPT_COPY_UNSAFE_LINKS, OPT_SAFE_LINKS, OPT_COMPARE_DEST,
       OPT_LOG_FORMAT, OPT_PASSWORD_FILE, OPT_SIZE_ONLY, OPT_ADDRESS,
-      OPT_DELETE_AFTER, OPT_EXISTING, OPT_MAX_DELETE};
+      OPT_DELETE_AFTER, OPT_EXISTING, OPT_MAX_DELETE, OPT_BACKUP_DIR};
 
 static char *short_options = "oblLWHpguDCtcahvqrRIxnSe:B:T:zP";
 
@@ -231,6 +233,7 @@ static struct option long_options[] = {
   {"log-format",  1,     0,    OPT_LOG_FORMAT},
   {"address",     1,     0,    OPT_ADDRESS},
   {"max-delete",  1,     0,    OPT_MAX_DELETE},
+  {"backup-dir",  1,     0,    OPT_BACKUP_DIR},
   {0,0,0,0}};
 
 
@@ -553,6 +556,10 @@ int parse_arguments(int argc, char *argv[], int frommain)
 			}
 			break;
 
+		case OPT_BACKUP_DIR:
+			backup_dir = optarg;
+			break;
+
 		default:
 			slprintf(err_buf,sizeof(err_buf),"unrecognised option\n");
 			return 0;
@@ -562,6 +569,8 @@ int parse_arguments(int argc, char *argv[], int frommain)
 }
 
 
+/* need to pass all the valid options from the client to the server */
+
 void server_options(char **args,int *argc)
 {
 	int ac = *argc;
@@ -680,6 +689,14 @@ void server_options(char **args,int *argc)
 		args[ac++] = tmpdir;
 	}
 
+	if (backup_dir && am_sender) {
+		/* only the receiver needs this option, if we are the sender
+		 *   then we need to send it to the receiver.
+		 */
+		args[ac++] = "--backup-dir";
+		args[ac++] = backup_dir;
+	}
+
 	if (compare_dest && am_sender) {
 		/* the server only needs this option if it is not the sender,
 		 *   and it may be an older version that doesn't know this

receiver.c

@@ -36,7 +36,6 @@ extern char *compare_dest;
 extern int make_backups;
 extern char *backup_suffix;
 
-
 static struct delete_list {
 	dev_t dev;
 	INO_T inode;
@@ -146,6 +145,7 @@ static void delete_files(struct file_list *flist)
 			if (-1 == flist_find(flist,local_file_list->files[i])) {
 				char *f = f_name(local_file_list->files[i]);
 				int k = strlen(f) - strlen(backup_suffix);
+/* Hi Andrew, do we really need to play with backup_suffix here? */
 				if (make_backups && ((k <= 0) ||
 					    (strcmp(f+k,backup_suffix) != 0))) {
 					(void) make_backup(f);
@@ -291,6 +291,8 @@ static int receive_data(int f_in,struct map_struct *buf,int fd,char *fname,
 }
 
 
+/* main routine for receiver process. Receiver process runs on the
+	same host as the generator process. */
 
 int recv_files(int f_in,struct file_list *flist,char *local_name,int f_gen)
 {  

rsync.c

@@ -259,6 +259,3 @@ void finish_transfer(char *fname, char *fnametmp, struct file_struct *file)
 		set_perms(fname,file,NULL,0);
 	}
 }
-
-
-

rsync.yo

@@ -223,6 +223,7 @@ verb(
  -r, --recursive             recurse into directories
  -R, --relative              use relative path names
  -b, --backup                make backups (default ~ suffix)
+     --backup-dir=DIR        put backups in the specified directory
      --suffix=SUFFIX         override backup suffix
  -u, --update                update only (don't overwrite newer files)
  -l, --links                 preserve soft links
@@ -348,6 +349,10 @@ dit(bf(-b, --backup)) With this option preexisting destination files are
 renamed with a ~ extension as each file is transferred.  You can
 control the backup suffix using the --suffix option.
 
+dit(bf(--backup-dir=DIR)) In combination with the --backup option, this
+tells rsync to store all backups in the specified directory. This is
+very useful for incremental backups.
+
 dit(bf(--suffix=SUFFIX)) This option allows you to override the default
 backup suffix used with the -b option. The default is a ~.