Ticket #1994: Sort files by version (like strverscmp(3) does)

Suppose we have 3 files with version in their names:
 * file-2.1.tgz
 * file-2.2.tgz
 * file-2.10.tgz

It is impossible to see them in natural order using standard facilities,
they will be sorted in alphabet order:
 * file-2.1.tgz
 * file-2.10.tgz
 * file-2.2.tgz

There was some attempts to fix this. I've picked up the patch by Roland Illig <roland illig gmx de>
(http://mail.gnome.org/archives/mc-devel/2004-July/msg00016.html) and adopted it for today's git snapshot.
It adds "version" option to the sort menu, which uses copy of strverscmp function from glibc.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>

lib/strutil.h

@@ -508,4 +508,5 @@ int str_isutf8 (const char *codeset_name);
 
 const char *str_detect_termencoding (void);
 
+int str_verscmp(const char *s1, const char *s2);
 #endif				/* MC_STRUTIL_H*/

lib/strutil/Makefile.am

@@ -5,7 +5,8 @@ libmcstrutil_la_SOURCES = \
 	strutil8bit.c \
 	strutilascii.c \
 	strutil.c \
-	strutilutf8.c
+	strutilutf8.c \
+	strverscmp.c
 
 
 

lib/strutil/strverscmp.c

@@ -0,0 +1,108 @@
+/* Compare strings while treating digits characters numerically.
+   Copyright (C) 1997, 2002 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jean-Fran<EFBFBD>ois Bignolles <bignolle ecoledoc ibp fr>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <ctype.h>
+#include "lib/strutil.h"
+
+/* states: S_N: normal, S_I: comparing integral part, S_F: comparing
+           fractionnal parts, S_Z: idem but with leading Zeroes only */
+#define  S_N    0x0
+#define  S_I    0x4
+#define  S_F    0x8
+#define  S_Z    0xC
+
+/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
+#define  CMP    2
+#define  LEN    3
+
+
+/* Compare S1 and S2 as strings holding indices/version numbers,
+   returning less than, equal to or greater than zero if S1 is less than,
+   equal to or greater than S2 (for more info, see the texinfo doc).
+*/
+
+int str_verscmp (const char *s1, const char *s2)
+{
+  unsigned char *p1 = (unsigned char *) s1;
+  unsigned char *p2 = (unsigned char *) s2;
+  unsigned char c1, c2;
+  int state;
+  int diff;
+
+  /* Symbol(s)    0       [1-9]   others  (padding)
+     Transition   (10) 0  (01) d  (00) x  (11) -   */
+  static const unsigned int next_state[] =
+  {
+      /* state    x    d    0    - */
+      /* S_N */  S_N, S_I, S_Z, S_N,
+      /* S_I */  S_N, S_I, S_I, S_I,
+      /* S_F */  S_N, S_F, S_F, S_F,
+      /* S_Z */  S_N, S_F, S_Z, S_Z
+  };
+
+  static const int result_type[] =
+  {
+      /* state   x/x  x/d  x/0  x/-  d/x  d/d  d/0  d/-
+                 0/x  0/d  0/0  0/-  -/x  -/d  -/0  -/- */
+
+      /* S_N */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
+                 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_I */  CMP, -1,  -1,  CMP, +1,  LEN, LEN, CMP,
+                 +1,  LEN, LEN, CMP, CMP, CMP, CMP, CMP,
+      /* S_F */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
+                 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_Z */  CMP, +1,  +1,  CMP, -1,  CMP, CMP, CMP,
+                 -1,  CMP, CMP, CMP
+  };
+
+  if (p1 == p2)
+    return 0;
+
+  c1 = *p1++;
+  c2 = *p2++;
+  /* Hint: '0' is a digit too.  */
+  state = S_N | ((c1 == '0') + (isdigit (c1) != 0));
+
+  while ((diff = c1 - c2) == 0 && c1 != '\0')
+    {
+      state = next_state[state];
+      c1 = *p1++;
+      c2 = *p2++;
+      state |= (c1 == '0') + (isdigit (c1) != 0);
+    }
+
+  state = result_type[state << 2 | (((c2 == '0') + (isdigit (c2) != 0)))];
+
+  switch (state)
+  {
+    case CMP:
+      return diff;
+
+    case LEN:
+      while (isdigit (*p1++))
+	if (!isdigit (*p2++))
+	  return 1;
+
+      return isdigit (*p2) ? -1 : diff;
+
+    default:
+      return state;
+  }
+}

src/dir.c

@@ -97,6 +97,19 @@ sort_name (file_entry *a, file_entry *b)
     return bd - ad;
 }
 
+int
+sort_vers (file_entry *a, file_entry *b)
+{
+    int ad = MY_ISDIR (a);
+    int bd = MY_ISDIR (b);
+
+    if (ad == bd || mix_all_files) {
+        return str_verscmp(a->fname, b->fname) * reverse;
+    } else {
+        return bd - ad;
+    }
+}
+
 int
 sort_ext (file_entry *a, file_entry *b)
 {

src/dir.h

@@ -54,6 +54,7 @@ int handle_path (dir_list *list, const char *path, struct stat *buf1,
 /* Sorting functions */
 int unsorted   (file_entry *a, file_entry *b);
 int sort_name  (file_entry *a, file_entry *b);
+int sort_vers  (file_entry *a, file_entry *b);
 int sort_ext   (file_entry *a, file_entry *b);
 int sort_time  (file_entry *a, file_entry *b);
 int sort_atime (file_entry *a, file_entry *b);

src/screen.c

@@ -448,6 +448,15 @@ panel_field_t panel_fields [] = {
 	string_file_name,
 	(sortfn *) sort_name
     },
+    {
+	"version", 12, 1, J_LEFT_FIT,
+	/* TRANSLATORS: one single character to represent 'version' sort mode  */
+	/* TRANSLATORS: no need to translate 'sort', it's just a context prefix  */
+	N_("sort|v"),
+	N_("&Version"), TRUE, FALSE,
+	string_file_name,
+	(sortfn *) sort_vers
+    },
     {
 	"extension", 12, 1, J_LEFT_FIT,
 	/* TRANSLATORS: one single character to represent 'extension' sort mode  */