cmdline: add new -S criteria: hH: Sort by number of hardlinks

docs/rmlint.1.rst

@@ -332,14 +332,15 @@ Original Detection Options
 
     Sort the files in a group of duplicates by one or more criteria.    
 
-    - **m**: keep lowest mtime (oldest)       **M**: keep highest mtime (newest)
-    - **a**: keep first alphabetically        **A**: keep last alphabetically
-    - **p**: keep first named path            **P**: keep last named path
-    - **d**: keep path with lowest depth      **D**: keep path with highest depth
-    - **l**: keep path with shortest basename **L**: keep path with longest basename
-    - **r**: keep paths matching regex        **R**: keep path not matching regex
-    - **r**: keep paths matching regex        **R**: keep path not matching regex
-    - **x**: keep basenames matching regex    **X**: keep basenames not matching regex
+    - **m**: keep lowest mtime (oldest)           **M**: keep highest mtime (newest)
+    - **a**: keep first alphabetically            **A**: keep last alphabetically
+    - **p**: keep first named path                **P**: keep last named path
+    - **d**: keep path with lowest depth          **D**: keep path with highest depth
+    - **l**: keep path with shortest basename     **L**: keep path with longest basename
+    - **r**: keep paths matching regex            **R**: keep path not matching regex
+    - **r**: keep paths matching regex            **R**: keep path not matching regex
+    - **x**: keep basenames matching regex        **X**: keep basenames not matching regex
+    - **h**: keep file with lowest hardlink count **H**: keep file with highest hardlink count
 
     Alphabetical sort will only use the basename of the file and ignore its case.
     One can have multiple criteria, e.g.: ``-S am`` will choose first alphabetically; if tied then by mtime.

lib/cmdline.c

@@ -1186,7 +1186,7 @@ static gboolean rm_cmd_parse_rankby(_UNUSED const char *option_name, const gchar
         return false;
     }
 
-    if(!rm_cmd_check_lettervec(option_name, cfg->sort_criteria, "dlamprxDLAMPRX",
+    if(!rm_cmd_check_lettervec(option_name, cfg->sort_criteria, "dlamprxhDLAMPRXH",
                                error)) {
         return false;
     }

lib/file.h

@@ -116,6 +116,10 @@ typedef struct RmFile {
      */
     short depth;
 
+	/* Link count (number of hardlinks + 1) of the file as told by stat()
+	 */
+	short link_count;
+
     /* Depth of the path of this file.
      */
     guint8 path_depth;

lib/preprocess.c

@@ -381,6 +381,9 @@ int rm_pp_cmp_orig_criteria(const RmFile *a, const RmFile *b, const RmSession *s
             case 'd':
                 cmp = (short)a->depth - (short)b->depth;
                 break;
+			case 'h':
+				cmp = (long)a->link_count - (long)b->link_count;
+				break;
             case 'p':
                 cmp = (long)a->path_index - (long)b->path_index;
                 break;

lib/traverse.c

@@ -173,6 +173,7 @@ static void rm_traverse_file(RmTravSession *trav_session, RmStat *statp,
         file->is_symlink = is_symlink;
         file->is_hidden = is_hidden;
         file->is_on_subvol_fs = is_on_subvol_fs;
+		file->link_count = statp->st_nlink;
 
         rm_file_list_insert_file(file, session);