Added MD5 hashing.

[finddup.git] / finddup.c

diff --git a/finddup.c b/finddup.c
index aa16dac..ccf21c6 100644 (file)
--- a/finddup.c
+++ b/finddup.c
@@ -23,7 +23,7 @@
  *
  */
 
-#define VERSION_NUMBER "0.8"
+#define VERSION_NUMBER "0.9"
 
 #define _BSD_SOURCE
 
@@ -40,6 +40,7 @@
 #include <locale.h>
 #include <getopt.h>
 #include <fcntl.h>
+#include <openssl/md5.h>
 
 /* 1M really helps compared to 64k */
 #define READ_BUFFER_SIZE (1024 * 1024)
@@ -71,6 +72,8 @@ int ignore_same_inode = 0; /* 1 means that comparison between two file
 int tty_width = -1; /* Positive value means what width to use to show
                        the progress bar */
 
+int use_md5 = 0; /* 1 means we keep an MD5 signature for each file */
+
 /********************************************************************/
 
 /* malloc with error checking.  */
@@ -102,6 +105,8 @@ struct file_node {
   ino_t inode;
   int group_id; /* one per identical file content */
   int dir_id; /* 1 for DIR1, and 2 for DIR2 */
+  int md5_computed;
+  unsigned char md5[MD5_DIGEST_LENGTH];
 };
 
 void file_list_delete(struct file_node *head) {
@@ -128,6 +133,21 @@ int file_list_length(struct file_node *head) {
 int same_content(struct file_node *f1, struct file_node *f2,
                  char *buffer1, char *buffer2) {
   int fd1, fd2, s1, s2;
+  MD5_CTX c1, c2;
+
+  if(use_md5) {
+    if(f1->md5_computed && f2->md5_computed &&
+       !memcmp(f1->md5, f2->md5, MD5_DIGEST_LENGTH)) {
+      return 0;
+    } else {
+      if(!f1->md5_computed) {
+        MD5_Init(&c1);
+      }
+      if(!f2->md5_computed) {
+        MD5_Init(&c2);
+      }
+    }
+  }
 
   fd1 = open(f1->name, O_RDONLY);
   fd2 = open(f2->name, O_RDONLY);
@@ -147,8 +167,26 @@ int same_content(struct file_node *f1, struct file_node *f2,
         if(s1 == 0) {
           close(fd1);
           close(fd2);
+          if(use_md5) {
+            if(!f1->md5_computed) {
+              MD5_Final(f1->md5, &c1);
+              f1->md5_computed = 1;
+            }
+            if(!f2->md5_computed) {
+              MD5_Final(f2->md5, &c2);
+              f2->md5_computed = 1;
+            }
+          }
           return 1;
         } else {
+          if(use_md5) {
+            if(!f1->md5_computed) {
+              MD5_Update(&c1, buffer1, s1);
+            }
+            if(!f2->md5_computed) {
+              MD5_Update(&c2, buffer2, s2);
+            }
+          }
           if(memcmp(buffer1, buffer2, s1)) {
             close(fd1);
             close(fd2);
@@ -228,6 +266,7 @@ struct file_node *scan_directory(struct file_node *tail, const char *name) {
           tmp->inode = sb.st_ino;
           tmp->group_id = -1;
           tmp->dir_id = -1;
+          tmp->md5_computed = 0;
           tail = tmp;
         }
       }
@@ -479,6 +518,7 @@ void print_help(FILE *out) {
   fprintf(out, "   -r, --real-paths           show the real file paths\n");
   fprintf(out, "   -i, --same-inodes-are-different\n");
   fprintf(out, "                              consider files with same inode as different\n");
+  fprintf(out, "   -m, --md5                  use MD5 hashing\n");
   fprintf(out, "\n");
   fprintf(out, "Report bugs and comments to <francois@fleuret.org>.\n");
 }
@@ -494,6 +534,7 @@ static struct option long_options[] = {
   { "ignore-dots", no_argument, 0, 'd' },
   { "ignore-empty", no_argument, 0, '0' },
   { "show-progress", no_argument, 0, 'p' },
+  { "md5", no_argument, 0, 'm' },
   { 0, 0, 0, 0 }
 };
 
@@ -502,7 +543,7 @@ int main(int argc, char **argv) {
 
   setlocale (LC_ALL, "");
 
-  while ((c = getopt_long(argc, argv, "hircgd0p",
+  while ((c = getopt_long(argc, argv, "hircgd0pm",
                           long_options, NULL)) != -1) {
     switch (c) {
 
@@ -540,6 +581,10 @@ int main(int argc, char **argv) {
       show_hits = 0;
       break;
 
+    case 'm':
+      use_md5 = 1;
+      break;
+
     default:
       exit(EXIT_FAILURE);
     }