From e95ec42dc178eff0410880c3dc4c0dac3df442df Mon Sep 17 00:00:00 2001
From: Adrian Lopez <adrianlopezroche@gmail.com>
Date: Tue, 23 Aug 2016 18:21:18 -0400
Subject: [PATCH] Add an option to sort duplicate files by ctime.

---
 README   |  5 +++--
 fdupes.1 |  2 +-
 fdupes.c | 49 +++++++++++++++++++++++++++++++++++++------------
 3 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/README b/README
index c748d05..c27f043 100644
--- a/README
+++ b/README
@@ -37,8 +37,9 @@ Usage: fdupes [options] DIRECTORY...
                   	grouping into sets; implies --noprompt
  -p --permissions 	don't consider files with different owner/group or
                   	permission bits as duplicates
- -o --order=BY    	select sort order for output, linking and deleting; by
-                  	mtime (BY='time'; default) or filename (BY='name')
+ -o --order=BY    	select sort order for output and deleting; by file
+                  	modification time (BY='time'; default), status
+                  	change time (BY='ctime'), or filename (BY='name')
  -i --reverse     	reverse order while sorting
  -v --version     	display fdupes version
  -h --help        	display this help message
diff --git a/fdupes.1 b/fdupes.1
index 5ddad87..969a5d8 100644
--- a/fdupes.1
+++ b/fdupes.1
@@ -72,7 +72,7 @@ don't consider files with different owner/group or permission bits as duplicates
 .TP
 .B -o --order\fR=\fIWORD\fR
 order files according to WORD:
-time - sort by mtime, name - sort by filename
+time - sort by modification time, ctime - sort by status change time, name - sort by filename
 .TP
 .B -i --reverse
 reverse order while sorting
diff --git a/fdupes.c b/fdupes.c
index ef64c45..7eee165 100644
--- a/fdupes.c
+++ b/fdupes.c
@@ -56,7 +56,8 @@
 #define F_IMMEDIATE         0x8000
 
 typedef enum {
-  ORDER_TIME = 0,
+  ORDER_MTIME = 0,
+  ORDER_CTIME,
   ORDER_NAME
 } ordertype_t;
 
@@ -64,6 +65,8 @@ char *program_name;
 
 unsigned long flags = 0;
 
+ordertype_t ordertype = ORDER_MTIME;
+
 #define CHUNK_SIZE 8192
 
 #define INPUT_SIZE 256
@@ -97,7 +100,7 @@ typedef struct _file {
   md5_byte_t *crcsignature;
   dev_t device;
   ino_t inode;
-  time_t mtime;
+  time_t sorttime;
   int hasdupes; /* true only if file is first on duplicate chain */
   struct _file *duplicates;
   struct _file *next;
@@ -183,6 +186,14 @@ time_t getmtime(char *filename) {
   return s.st_mtime;
 }
 
+time_t getctime(char *filename) {
+  struct stat s;
+
+  if (stat(filename, &s) != 0) return 0;
+
+  return s.st_ctime;
+}
+
 char **cloneargs(int argc, char **argv)
 {
   int x;
@@ -435,7 +446,17 @@ void getfilestats(file_t *file)
   file->size = filesize(file->d_name);
   file->inode = getinode(file->d_name);
   file->device = getdevice(file->d_name);
-  file->mtime = getmtime(file->d_name);
+
+  switch (ordertype)
+  {
+    case ORDER_CTIME:
+      file->sorttime = getctime(file->d_name);
+      break;
+    case ORDER_MTIME: 
+    default:
+      file->sorttime = getmtime(file->d_name);
+      break;
+  }
 }
 
 int registerfile(filetree_t **branch, file_t *file)
@@ -911,11 +932,11 @@ int sort_pairs_by_arrival(file_t *f1, file_t *f2)
   return !ISFLAG(flags, F_REVERSE) ? -1 : 1;
 }
 
-int sort_pairs_by_mtime(file_t *f1, file_t *f2)
+int sort_pairs_by_time(file_t *f1, file_t *f2)
 {
-  if (f1->mtime < f2->mtime)
+  if (f1->sorttime < f2->sorttime)
     return !ISFLAG(flags, F_REVERSE) ? -1 : 1;
-  else if (f1->mtime > f2->mtime)
+  else if (f1->sorttime > f2->sorttime)
     return !ISFLAG(flags, F_REVERSE) ? 1 : -1;
 
   return 0;
@@ -1038,8 +1059,9 @@ void help_text()
   printf("                  \tgrouping into sets; implies --noprompt\n");
   printf(" -p --permissions \tdon't consider files with different owner/group or\n");
   printf("                  \tpermission bits as duplicates\n");
-  printf(" -o --order=BY    \tselect sort order for output, linking and deleting; by\n");
-  printf("                  \tmtime (BY='time'; default) or filename (BY='name')\n");
+  printf(" -o --order=BY    \tselect sort order for output and deleting; by file\n");
+  printf("                  \tmodification time (BY='time'; default), status\n");
+  printf("                  \tchange time (BY='ctime'), or filename (BY='name')\n");
   printf(" -i --reverse     \treverse order while sorting\n");
   printf(" -v --version     \tdisplay fdupes version\n");
   printf(" -h --help        \tdisplay this help message\n\n");
@@ -1061,7 +1083,6 @@ int main(int argc, char **argv) {
   int progress = 0;
   char **oldargv;
   int firstrecurse;
-  ordertype_t ordertype = ORDER_TIME;
   
 #ifndef OMIT_GETOPT_LONG
   static struct option long_options[] = 
@@ -1161,7 +1182,9 @@ int main(int argc, char **argv) {
       if (!strcasecmp("name", optarg)) {
         ordertype = ORDER_NAME;
       } else if (!strcasecmp("time", optarg)) {
-        ordertype = ORDER_TIME;
+        ordertype = ORDER_MTIME;
+      } else if (!strcasecmp("ctime", optarg)) {
+        ordertype = ORDER_CTIME;
       } else {
         errormsg("invalid value for --order: '%s'\n", optarg);
         exit(1);
@@ -1247,10 +1270,12 @@ int main(int argc, char **argv) {
       if (confirmmatch(file1, file2)) {
         if (ISFLAG(flags, F_DELETEFILES) && ISFLAG(flags, F_IMMEDIATE))
           deletesuccessor(match, curfile,
-              (ordertype == ORDER_TIME) ? sort_pairs_by_mtime : sort_pairs_by_filename );
+              (ordertype == ORDER_MTIME || 
+               ordertype == ORDER_CTIME) ? sort_pairs_by_time : sort_pairs_by_filename );
         else
           registerpair(match, curfile,
-              (ordertype == ORDER_TIME) ? sort_pairs_by_mtime : sort_pairs_by_filename );
+              (ordertype == ORDER_MTIME ||
+               ordertype == ORDER_CTIME) ? sort_pairs_by_time : sort_pairs_by_filename );
       }
       
       fclose(file1);