- attempt to save database more safely

- create a backup file when saving

diff --git a/database.c b/database.c
index 893cb9902cd5dd8456394007b9108e8b4a9d38c9..bd8877164e61675b85f3d3b4ca3749797d212ed6 100644 (file)
--- a/database.c
+++ b/database.c
@@ -345,23 +345,41 @@ int
 save_database()
 {
        FILE *out;
+       int ret = 0;
        struct db_enumerator e = init_db_enumerator(ENUM_ALL);
+       char *datafile_new = strconcat(datafile, ".new", NULL);
+       char *datafile_old = strconcat(datafile, "~", NULL);
 
-       if( (out = abook_fopen(datafile, "w")) == NULL )
-               return -1;
+       if( (out = abook_fopen(datafile_new, "w")) == NULL ) {
+               ret = -1;
+               goto out;
+       }
 
        if(list_is_empty()) {
                fclose(out);
                unlink(datafile);
-               return 1;
+               ret = 1;
+               goto out;
        }
 
-
+       /*
+        * Possibly should check if write_database failed.
+        * Currently it returns always zero.
+        */
        write_database(out, e);
-
        fclose(out);
 
-       return 0;
+       if(access(datafile, F_OK) == 0 &&
+                       (rename(datafile, datafile_old)) == -1)
+               ret = -1;
+       
+       if((rename(datafile_new, datafile)) == -1)
+               ret = -1;
+
+out:
+       free(datafile_new);
+       free(datafile_old);
+       return ret;
 }
 
 static void