fdupes.c

/* FDUPES Copyright (c) 1999-2018 Adrian Lopez

   Permission is hereby granted, free of charge, to any person
   obtaining a copy of this software and associated documentation files
   (the "Software"), to deal in the Software without restriction,
   including without limitation the rights to use, copy, modify, merge,
   publish, distribute, sublicense, and/or sell copies of the Software,
   and to permit persons to whom the Software is furnished to do so,
   subject to the following conditions:

   The above copyright notice and this permission notice shall be
   included in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
   IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 
   CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
   TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 
   SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */

#include "config.h"
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <strings.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <stdlib.h>
#include <time.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#include <errno.h>
#include <libgen.h>
#include <locale.h>
#ifdef HAVE_NCURSESW_CURSES_H
  #include <ncursesw/curses.h>
#else
  #include <curses.h>
#endif
#include "fdupes.h"
#include "errormsg.h"
#include "ncurses-interface.h"
#include "log.h"
#include "sigint.h"
#include "flags.h"

long long minsize = -1;
long long maxsize = -1;

typedef enum {
  ORDER_MTIME = 0,
  ORDER_CTIME,
  ORDER_NAME
} ordertype_t;

char *program_name;

ordertype_t ordertype = ORDER_MTIME;

#define CHUNK_SIZE 8192

#define INPUT_SIZE 256

#define PARTIAL_MD5_SIZE 4096

#define MD5_DIGEST_LENGTH 16

/* 

TODO: Partial sums (for working with very large files).

typedef struct _signature
{
  md5_state_t state;
  md5_byte_t  digest[16];
} signature_t;

typedef struct _signatures
{
  int         num_signatures;
  signature_t *signatures;
} signatures_t;

*/

typedef struct _filetree {
  file_t *file; 
  struct _filetree *left;
  struct _filetree *right;
} filetree_t;

void escapefilename(char *escape_list, char **filename_ptr)
{
  int x;
  int tx;
  char *tmp;
  char *filename;

  filename = *filename_ptr;

  tmp = (char*) malloc(strlen(filename) * 2 + 1);
  if (tmp == NULL) {
    errormsg("out of memory!\n");
    exit(1);
  }

  for (x = 0, tx = 0; x < strlen(filename); x++) {
    if (strchr(escape_list, filename[x]) != NULL) tmp[tx++] = '\\';
    tmp[tx++] = filename[x];
  }

  tmp[tx] = '\0';

  if (x != tx) {
    *filename_ptr = realloc(*filename_ptr, strlen(tmp) + 1);
    if (*filename_ptr == NULL) {
      errormsg("out of memory!\n");
      exit(1);
    }
    strcpy(*filename_ptr, tmp);
  }
}

off_t filesize(char *filename) {
  struct stat s;

  if (stat(filename, &s) != 0) return -1;

  return s.st_size;
}

dev_t getdevice(char *filename) {
  struct stat s;

  if (stat(filename, &s) != 0) return 0;

  return s.st_dev;
}

ino_t getinode(char *filename) {
  struct stat s;
   
  if (stat(filename, &s) != 0) return 0;

  return s.st_ino;   
}

time_t getmtime(char *filename) {
  struct stat s;

  if (stat(filename, &s) != 0) return 0;

  return s.st_mtime;
}

time_t getctime(char *filename) {
  struct stat s;

  if (stat(filename, &s) != 0) return 0;

  return s.st_ctime;
}

char *fmtmtime(char *filename) {
  static char buf[64];
  time_t t = getmtime(filename);

  strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M", localtime(&t));
  return buf;
}

char **cloneargs(int argc, char **argv)
{
  int x;
  char **args;

  args = (char **) malloc(sizeof(char*) * argc);
  if (args == NULL) {
    errormsg("out of memory!\n");
    exit(1);
  }

  for (x = 0; x < argc; x++) {
    args[x] = (char*) malloc(strlen(argv[x]) + 1);
    if (args[x] == NULL) {
      free(args);
      errormsg("out of memory!\n");
      exit(1);
    }

    strcpy(args[x], argv[x]);
  }

  return args;
}

int findarg(char *arg, int start, int argc, char **argv)
{
  int x;
  
  for (x = start; x < argc; x++)
    if (strcmp(argv[x], arg) == 0) 
      return x;

  return x;
}

/* Find the first non-option argument after specified option. */
int nonoptafter(char *option, int argc, char **oldargv, 
		      char **newargv, int optind) 
{
  int x;
  int targetind;
  int testind;
  int startat = 1;

  targetind = findarg(option, 1, argc, oldargv);
    
  for (x = optind; x < argc; x++) {
    testind = findarg(newargv[x], startat, argc, oldargv);
    if (testind > targetind) return x;
    else startat = testind;
  }

  return x;
}

void getfilestats(file_t *file)
{
  file->size = filesize(file->d_name);
  file->inode = getinode(file->d_name);
  file->device = getdevice(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 grokdir(char *dir, file_t **filelistp, struct stat *logfile_status)
{
  DIR *cd;
  file_t *newfile;
  struct dirent *dirinfo;
  int lastchar;
  int filecount = 0;
  struct stat info;
  struct stat linfo;
  static int progress = 0;
  static char indicator[] = "-\\|/";
  char *fullname, *name;
  off_t size;

  cd = opendir(dir);

  if (!cd) {
    errormsg("could not chdir to %s\n", dir);
    return 0;
  }

  while ((dirinfo = readdir(cd)) != NULL) {
    if (strcmp(dirinfo->d_name, ".") && strcmp(dirinfo->d_name, "..")) {
      if (!ISFLAG(flags, F_HIDEPROGRESS)) {
	fprintf(stderr, "\rBuilding file list %c ", indicator[progress]);
	progress = (progress + 1) % 4;
      }

      newfile = (file_t*) malloc(sizeof(file_t));

      if (!newfile) {
	errormsg("out of memory!\n");
	closedir(cd);
	exit(1);
      } else newfile->next = *filelistp;

      newfile->device = 0;
      newfile->inode = 0;
      newfile->crcsignature = NULL;
      newfile->crcpartial = NULL;
      newfile->duplicates = NULL;
      newfile->hasdupes = 0;

      newfile->d_name = (char*)malloc(strlen(dir)+strlen(dirinfo->d_name)+2);

      if (!newfile->d_name) {
	errormsg("out of memory!\n");
	free(newfile);
	closedir(cd);
	exit(1);
      }

      strcpy(newfile->d_name, dir);
      lastchar = strlen(dir) - 1;
      if (lastchar >= 0 && dir[lastchar] != '/')
	strcat(newfile->d_name, "/");
      strcat(newfile->d_name, dirinfo->d_name);
      
      if (ISFLAG(flags, F_EXCLUDEHIDDEN)) {
	fullname = strdup(newfile->d_name);
	if (fullname == 0)
	{
	  errormsg("out of memory!\n");
	  free(newfile);
	  closedir(cd);
	  exit(1);
	}
	name = basename(fullname);
	if (name[0] == '.' && strcmp(name, ".") && strcmp(name, "..") ) {
	  free(newfile->d_name);
	  free(newfile);
	  continue;
	}
	free(fullname);
      }

      size = filesize(newfile->d_name);
      if ((size == 0 && ISFLAG(flags, F_EXCLUDEEMPTY)) || size < minsize || (size > maxsize && maxsize != -1)) {
	free(newfile->d_name);
	free(newfile);
	continue;
      }

      if (stat(newfile->d_name, &info) == -1) {
	free(newfile->d_name);
	free(newfile);
	continue;
      }

      if (info.st_dev == logfile_status->st_dev && info.st_ino == logfile_status->st_ino)
      {
        free(newfile->d_name);
        free(newfile);
        continue;
      }

      if (lstat(newfile->d_name, &linfo) == -1) {
	free(newfile->d_name);
	free(newfile);
	continue;
      }

      if (S_ISDIR(info.st_mode)) {
	if (ISFLAG(flags, F_RECURSE) && (ISFLAG(flags, F_FOLLOWLINKS) || !S_ISLNK(linfo.st_mode)))
	  filecount += grokdir(newfile->d_name, filelistp, logfile_status);
	free(newfile->d_name);
	free(newfile);
      } else {
	if (S_ISREG(linfo.st_mode) || (S_ISLNK(linfo.st_mode) && ISFLAG(flags, F_FOLLOWLINKS))) {
	  getfilestats(newfile);
	  *filelistp = newfile;
	  filecount++;
	} else {
	  free(newfile->d_name);
	  free(newfile);
	}
      }
    }
  }

  closedir(cd);

  return filecount;
}

md5_byte_t *getcrcsignatureuntil(char *filename, off_t max_read)
{
  off_t fsize;
  off_t toread;
  md5_state_t state;
  static md5_byte_t digest[MD5_DIGEST_LENGTH];  
  static md5_byte_t chunk[CHUNK_SIZE];
  FILE *file;
   
  md5_init(&state);

 
  fsize = filesize(filename);
  
  if (max_read != 0 && fsize > max_read)
    fsize = max_read;

  file = fopen(filename, "rb");
  if (file == NULL) {
    errormsg("error opening file %s\n", filename);
    return NULL;
  }
 
  while (fsize > 0) {
    toread = (fsize >= CHUNK_SIZE) ? CHUNK_SIZE : fsize;
    if (fread(chunk, toread, 1, file) != 1) {
      errormsg("error reading from file %s\n", filename);
      fclose(file);
      return NULL;
    }
    md5_append(&state, chunk, toread);
    fsize -= toread;
  }

  md5_finish(&state, digest);

  fclose(file);

  return digest;
}

md5_byte_t *getcrcsignature(char *filename)
{
  return getcrcsignatureuntil(filename, 0);
}

md5_byte_t *getcrcpartialsignature(char *filename)
{
  return getcrcsignatureuntil(filename, PARTIAL_MD5_SIZE);
}

int md5cmp(const md5_byte_t *a, const md5_byte_t *b)
{
  int x;

  for (x = 0; x < MD5_DIGEST_LENGTH; ++x)
  {
    if (a[x] < b[x])
      return -1;
    else if (a[x] > b[x])
      return 1;
  }

  return 0;
}

void md5copy(md5_byte_t *to, const md5_byte_t *from)
{
  int x;

  for (x = 0; x < MD5_DIGEST_LENGTH; ++x)
    to[x] = from[x];
}

void purgetree(filetree_t *checktree)
{
  if (checktree->left != NULL) purgetree(checktree->left);
    
  if (checktree->right != NULL) purgetree(checktree->right);
    
  free(checktree);
}

int registerfile(filetree_t **branch, file_t *file)
{
  *branch = (filetree_t*) malloc(sizeof(filetree_t));
  if (*branch == NULL) {
    errormsg("out of memory!\n");
    exit(1);
  }
  
  (*branch)->file = file;
  (*branch)->left = NULL;
  (*branch)->right = NULL;

  return 1;
}

int same_permissions(char* name1, char* name2)
{
    struct stat s1, s2;

    if (stat(name1, &s1) != 0) return -1;
    if (stat(name2, &s2) != 0) return -1;

    return (s1.st_mode == s2.st_mode &&
            s1.st_uid == s2.st_uid &&
            s1.st_gid == s2.st_gid);
}

int is_hardlink(filetree_t *checktree, file_t *file)
{
  file_t *dupe;

  if ((file->inode == checktree->file->inode) &&
      (file->device == checktree->file->device))
        return 1;

  if (checktree->file->hasdupes)
  {
    dupe = checktree->file->duplicates;

    do {
      if ((file->inode == dupe->inode) &&
          (file->device == dupe->device))
            return 1;

      dupe = dupe->duplicates;
    } while (dupe != NULL);
  }

  return 0;
}

/* check whether two paths represent the same file (deleting one would delete the other) */
int is_same_file(file_t *file_a, file_t *file_b)
{
  char *filename_a;
  char *filename_b;
  char *dirname_a;
  char *dirname_b;
  char *basename_a;
  char *basename_b;
  struct stat dirstat_a;
  struct stat dirstat_b;

  /* if files on different devices and/or different inodes, they are not the same file */
  if (file_a->device != file_b->device || file_a->inode != file_b->inode)
    return 0;

  /* copy filenames (basename and dirname may modify these) */
  filename_a = strdup(file_a->d_name);
  if (filename_a == 0)
    return -1;

  filename_b = strdup(file_b->d_name);
  if (filename_b == 0)
    return -1;

  /* get file basenames */
  basename_a = basename(filename_a);
  memmove(filename_a, basename_a, strlen(basename_a) + 1);

  basename_b = basename(filename_b);
  memmove(filename_b, basename_b, strlen(basename_b) + 1);

  /* if files have different names, they are not the same file */
  if (strcmp(filename_a, filename_b) != 0)
  {
    free(filename_b);
    free(filename_a);
    return 0;
  }

  /* restore paths */
  strcpy(filename_a, file_a->d_name);
  strcpy(filename_b, file_b->d_name);

  /* get directory names */
  dirname_a = dirname(filename_a);
  if (stat(dirname_a, &dirstat_a) != 0)
  {
    free(filename_b);
    free(filename_a);
    return -1;
  }

  dirname_b = dirname(filename_b);
  if (stat(dirname_b, &dirstat_b) != 0)
  {
    free(filename_b);
    free(filename_a);
    return -1;
  }

  free(filename_b);
  free(filename_a);

  /* if directories on which files reside are different, they are not the same file */
  if (dirstat_a.st_dev != dirstat_b.st_dev || dirstat_a.st_ino != dirstat_b.st_ino)
    return 0;

  /* same device, inode, filename, and directory; therefore, same file */
  return 1;
}

/* check whether given tree node already contains a copy of given file */
int has_same_file(filetree_t *checktree, file_t *file)
{
  file_t *dupe;

  if (is_same_file(checktree->file, file))
    return 1;

  if (checktree->file->hasdupes)
  {
    dupe = checktree->file->duplicates;

    do {
      if (is_same_file(dupe, file))
        return 1;

      dupe = dupe->duplicates;
    } while (dupe != NULL);
  }

  return 0;
}

file_t **checkmatch(filetree_t **root, filetree_t *checktree, file_t *file)
{
  int cmpresult;
  md5_byte_t *crcsignature;
  off_t fsize;

  if (ISFLAG(flags, F_CONSIDERHARDLINKS))
  {
    /* If node already contains file, we don't want to add it again.
    */
    if (has_same_file(checktree, file))
      return NULL;
  }
  else
  {
    /* If device and inode fields are equal one of the files is a
       hard link to the other or the files have been listed twice
       unintentionally. We don't want to flag these files as
       duplicates unless the user specifies otherwise.
    */
    if (is_hardlink(checktree, file))
      return NULL;
  }

  fsize = filesize(file->d_name);
  
  if (fsize < checktree->file->size) 
    cmpresult = -1;
  else 
    if (fsize > checktree->file->size) cmpresult = 1;
  else
    if (ISFLAG(flags, F_PERMISSIONS) &&
        !same_permissions(file->d_name, checktree->file->d_name))
        cmpresult = -1;
  else {
    if (checktree->file->crcpartial == NULL) {
      crcsignature = getcrcpartialsignature(checktree->file->d_name);
      if (crcsignature == NULL) {
        errormsg ("cannot read file %s\n", checktree->file->d_name);
        return NULL;
      }

      checktree->file->crcpartial = (md5_byte_t*) malloc(MD5_DIGEST_LENGTH * sizeof(md5_byte_t));
      if (checktree->file->crcpartial == NULL) {
	errormsg("out of memory\n");
	exit(1);
      }
      md5copy(checktree->file->crcpartial, crcsignature);
    }

    if (file->crcpartial == NULL) {
      crcsignature = getcrcpartialsignature(file->d_name);
      if (crcsignature == NULL) {
        errormsg ("cannot read file %s\n", file->d_name);
        return NULL;
      }

      file->crcpartial = (md5_byte_t*) malloc(MD5_DIGEST_LENGTH * sizeof(md5_byte_t));
      if (file->crcpartial == NULL) {
	errormsg("out of memory\n");
	exit(1);
      }
      md5copy(file->crcpartial, crcsignature);
    }

    cmpresult = md5cmp(file->crcpartial, checktree->file->crcpartial);
    /*if (cmpresult != 0) errormsg("    on %s vs %s\n", file->d_name, checktree->file->d_name);*/

    if (cmpresult == 0) {
      if (checktree->file->crcsignature == NULL) {
	crcsignature = getcrcsignature(checktree->file->d_name);
	if (crcsignature == NULL) return NULL;

	checktree->file->crcsignature = (md5_byte_t*) malloc(MD5_DIGEST_LENGTH * sizeof(md5_byte_t));
	if (checktree->file->crcsignature == NULL) {
	  errormsg("out of memory\n");
	  exit(1);
	}
	md5copy(checktree->file->crcsignature, crcsignature);
      }

      if (file->crcsignature == NULL) {
	crcsignature = getcrcsignature(file->d_name);
	if (crcsignature == NULL) return NULL;

	file->crcsignature = (md5_byte_t*) malloc(MD5_DIGEST_LENGTH * sizeof(md5_byte_t));
	if (file->crcsignature == NULL) {
	  errormsg("out of memory\n");
	  exit(1);
	}
	md5copy(file->crcsignature, crcsignature);
      }

      cmpresult = md5cmp(file->crcsignature, checktree->file->crcsignature);
      /*if (cmpresult != 0) errormsg("P   on %s vs %s\n", 
          file->d_name, checktree->file->d_name);
      else errormsg("P F on %s vs %s\n", file->d_name,
          checktree->file->d_name);
      printf("%s matches %s\n", file->d_name, checktree->file->d_name);*/
    }
  }

  if (cmpresult < 0) {
    if (checktree->left != NULL) {
      return checkmatch(root, checktree->left, file);
    } else {
      registerfile(&(checktree->left), file);
      return NULL;
    }
  } else if (cmpresult > 0) {
    if (checktree->right != NULL) {
      return checkmatch(root, checktree->right, file);
    } else {
      registerfile(&(checktree->right), file);
      return NULL;
    }
  } else 
  {
    return &checktree->file;
  }
}

/* Do a bit-for-bit comparison in case two different files produce the 
   same signature. Unlikely, but better safe than sorry. */

int confirmmatch(FILE *file1, FILE *file2)
{
  unsigned char c1[CHUNK_SIZE];
  unsigned char c2[CHUNK_SIZE];
  size_t r1;
  size_t r2;
  
  fseek(file1, 0, SEEK_SET);
  fseek(file2, 0, SEEK_SET);

  do {
    r1 = fread(c1, sizeof(unsigned char), sizeof(c1), file1);
    r2 = fread(c2, sizeof(unsigned char), sizeof(c2), file2);

    if (r1 != r2) return 0; /* file lengths are different */
    if (memcmp (c1, c2, r1)) return 0; /* file contents are different */
  } while (r2);
  
  return 1;
}

void summarizematches(file_t *files)
{
  int numsets = 0;
  double numbytes = 0.0;
  int numfiles = 0;
  file_t *tmpfile;

  while (files != NULL)
  {
    if (files->hasdupes)
    {
      numsets++;

      tmpfile = files->duplicates;
      while (tmpfile != NULL)
      {
	numfiles++;
	numbytes += files->size;
	tmpfile = tmpfile->duplicates;
      }
    }

    files = files->next;
  }

  if (numsets == 0)
    printf("No duplicates found.\n\n");
  else
  {
    if (numbytes < 1024.0)
      printf("%d duplicate files (in %d sets), occupying %.0f bytes.\n\n", numfiles, numsets, numbytes);
    else if (numbytes <= (1000.0 * 1000.0))
      printf("%d duplicate files (in %d sets), occupying %.1f kilobytes\n\n", numfiles, numsets, numbytes / 1000.0);
    else
      printf("%d duplicate files (in %d sets), occupying %.1f megabytes\n\n", numfiles, numsets, numbytes / (1000.0 * 1000.0));
 
  }
}

void printmatches(file_t *files)
{
  file_t *tmpfile;

  while (files != NULL) {
    if (files->hasdupes) {
      if (!ISFLAG(flags, F_OMITFIRST)) {
	if (ISFLAG(flags, F_SHOWSIZE)) printf("%lld byte%seach:\n", (long long int)files->size,
	 (files->size != 1) ? "s " : " ");
        if (ISFLAG(flags, F_SHOWTIME))
          printf("%s ", fmtmtime(files->d_name));
	if (ISFLAG(flags, F_DSAMELINE)) escapefilename("\\ ", &files->d_name);
	printf("%s%c", files->d_name, ISFLAG(flags, F_DSAMELINE)?' ':'\n');
      }
      tmpfile = files->duplicates;
      while (tmpfile != NULL) {
        if (ISFLAG(flags, F_SHOWTIME))
          printf("%s ", fmtmtime(tmpfile->d_name));
	if (ISFLAG(flags, F_DSAMELINE)) escapefilename("\\ ", &tmpfile->d_name);
	printf("%s%c", tmpfile->d_name, ISFLAG(flags, F_DSAMELINE)?' ':'\n');
	tmpfile = tmpfile->duplicates;
      }
      printf("\n");

    }
      
    files = files->next;
  }
}

/*
#define REVISE_APPEND "_tmp"
char *revisefilename(char *path, int seq)
{
  int digits;
  char *newpath;
  char *scratch;
  char *dot;

  digits = numdigits(seq);
  newpath = malloc(strlen(path) + strlen(REVISE_APPEND) + digits + 1);
  if (!newpath) return newpath;

  scratch = malloc(strlen(path) + 1);
  if (!scratch) return newpath;

  strcpy(scratch, path);
  dot = strrchr(scratch, '.');
  if (dot) 
  {
    *dot = 0;
    sprintf(newpath, "%s%s%d.%s", scratch, REVISE_APPEND, seq, dot + 1);
  }

  else
  {
    sprintf(newpath, "%s%s%d", path, REVISE_APPEND, seq);
  }

  free(scratch);

  return newpath;
} */

int relink(char *oldfile, char *newfile)
{
  dev_t od;
  dev_t nd;
  ino_t oi;
  ino_t ni;

  od = getdevice(oldfile);
  oi = getinode(oldfile);

  if (link(oldfile, newfile) != 0)
    return 0;

  /* make sure we're working with the right file (the one we created) */
  nd = getdevice(newfile);
  ni = getinode(newfile);

  if (nd != od || oi != ni)
    return 0; /* file is not what we expected */

  return 1;
}

void deletefiles(file_t *files, int prompt, FILE *tty, char *logfile)
{
  int counter;
  int groups = 0;
  int curgroup = 0;
  file_t *tmpfile;
  file_t *curfile;
  file_t **dupelist;
  int *preserve;
  char *preservestr;
  char *token;
  char *tstr;
  int number;
  int sum;
  int max = 0;
  int x;
  int i;
  struct log_info *loginfo;
  int log_error;

  curfile = files;
  
  while (curfile) {
    if (curfile->hasdupes) {
      counter = 1;
      groups++;

      tmpfile = curfile->duplicates;
      while (tmpfile) {
	counter++;
	tmpfile = tmpfile->duplicates;
      }
      
      if (counter > max) max = counter;
    }
    
    curfile = curfile->next;
  }

  max++;

  dupelist = (file_t**) malloc(sizeof(file_t*) * max);
  preserve = (int*) malloc(sizeof(int) * max);
  preservestr = (char*) malloc(INPUT_SIZE);

  if (!dupelist || !preserve || !preservestr) {
    errormsg("out of memory\n");
    exit(1);
  }

  loginfo = 0;
  if (logfile != 0)
    loginfo = log_open(logfile, &log_error);

  register_sigint_handler();

  while (files) {
    if (files->hasdupes) {
      curgroup++;
      counter = 1;
      dupelist[counter] = files;

      if (prompt) 
      {
        if (ISFLAG(flags, F_SHOWTIME))
          printf("[%d] [%s] %s\n", counter, fmtmtime(files->d_name), files->d_name);
        else
          printf("[%d] %s\n", counter, files->d_name);
      }

      tmpfile = files->duplicates;

      while (tmpfile) {
	dupelist[++counter] = tmpfile;
        if (prompt)
        {
          if (ISFLAG(flags, F_SHOWTIME))
            printf("[%d] [%s] %s\n", counter, fmtmtime(tmpfile->d_name), tmpfile->d_name);
          else
            printf("[%d] %s\n", counter, tmpfile->d_name);
        }
	tmpfile = tmpfile->duplicates;
      }

      if (prompt) printf("\n");

      if (!prompt) /* preserve only the first file */
      {
         preserve[1] = 1;
	 for (x = 2; x <= counter; x++) preserve[x] = 0;
      }

      else /* prompt for files to preserve */

      do {
	printf("Set %d of %d, preserve files [1 - %d, all, quit]",
          curgroup, groups, counter);
	if (ISFLAG(flags, F_SHOWSIZE)) printf(" (%lld byte%seach)", (long long int)files->size,
	  (files->size != 1) ? "s " : " ");
	printf(": ");
	fflush(stdout);

	if (!fgets(preservestr, INPUT_SIZE, tty))
	{
	  preservestr[0] = '\n'; /* treat fgets() failure as if nothing was entered */
	  preservestr[1] = '\0';

	  if (got_sigint)
	  {
	    if (loginfo)
	      log_close(loginfo);

	    free(dupelist);
	    free(preserve);
	    free(preservestr);

	    printf("\n");

	    exit(0);
	  }
	}

	i = strlen(preservestr) - 1;

	while (preservestr[i]!='\n'){ /* tail of buffer must be a newline */
	  tstr = (char*)
	    realloc(preservestr, strlen(preservestr) + 1 + INPUT_SIZE);
	  if (!tstr) { /* couldn't allocate memory, treat as fatal */
	    errormsg("out of memory!\n");
	    exit(1);
	  }

	  preservestr = tstr;
	  if (!fgets(preservestr + i + 1, INPUT_SIZE, tty))
	  {
	    preservestr[0] = '\n'; /* treat fgets() failure as if nothing was entered */
	    preservestr[1] = '\0';
	    break;
	  }
	  i = strlen(preservestr)-1;
	}

	if (strcmp(preservestr, "q\n") == 0 || strcmp(preservestr, "quit\n") == 0)
	{
	  if (loginfo)
	    log_close(loginfo);

	  free(dupelist);
	  free(preserve);
	  free(preservestr);

	  printf("\n");

	  exit(0);
	}

	for (x = 1; x <= counter; x++) preserve[x] = 0;
	
	token = strtok(preservestr, " ,\n");
	
	while (token != NULL) {
	  if (strcasecmp(token, "all") == 0 || strcasecmp(token, "a") == 0)
	    for (x = 0; x <= counter; x++) preserve[x] = 1;
	  
	  number = 0;
	  sscanf(token, "%d", &number);
	  if (number > 0 && number <= counter) preserve[number] = 1;
	  
	  token = strtok(NULL, " ,\n");
	}
      
	for (sum = 0, x = 1; x <= counter; x++) sum += preserve[x];
      } while (sum < 1); /* make sure we've preserved at least one file */

      printf("\n");

      if (loginfo)
        log_begin_set(loginfo);

      for (x = 1; x <= counter; x++) { 
	if (preserve[x])
        {
	  printf("   [+] %s\n", dupelist[x]->d_name);

          if (loginfo)
            log_file_remaining(loginfo, dupelist[x]->d_name);
        }
	else {
	  if (remove(dupelist[x]->d_name) == 0) {
	    printf("   [-] %s\n", dupelist[x]->d_name);

            if (loginfo)
              log_file_deleted(loginfo, dupelist[x]->d_name);
	  } else {
	    printf("   [!] %s ", dupelist[x]->d_name);
	    printf("-- unable to delete file!\n");

            if (loginfo)
              log_file_remaining(loginfo, dupelist[x]->d_name);
	  }
	}
      }
      printf("\n");

      if (loginfo)
        log_end_set(loginfo);
    }
    
    files = files->next;
  }

  if (loginfo)
    log_close(loginfo);

  free(dupelist);
  free(preserve);
  free(preservestr);
}

int sort_pairs_by_arrival(file_t *f1, file_t *f2)
{
  if (f2->duplicates != 0)
    return !ISFLAG(flags, F_REVERSE) ? 1 : -1;

  return !ISFLAG(flags, F_REVERSE) ? -1 : 1;
}

int sort_pairs_by_time(file_t *f1, file_t *f2)
{
  if (f1->sorttime < f2->sorttime)
    return !ISFLAG(flags, F_REVERSE) ? -1 : 1;
  else if (f1->sorttime > f2->sorttime)
    return !ISFLAG(flags, F_REVERSE) ? 1 : -1;

  return 0;
}

int sort_pairs_by_filename(file_t *f1, file_t *f2)
{
  int strvalue = strcmp(f1->d_name, f2->d_name);
  return !ISFLAG(flags, F_REVERSE) ? strvalue : -strvalue;
}

void registerpair(file_t **matchlist, file_t *newmatch, 
		  int (*comparef)(file_t *f1, file_t *f2))
{
  file_t *traverse;
  file_t *back;

  (*matchlist)->hasdupes = 1;

  back = 0;
  traverse = *matchlist;
  while (traverse)
  {
    if (comparef(newmatch, traverse) <= 0)
    {
      newmatch->duplicates = traverse;
      
      if (back == 0)
      {
	*matchlist = newmatch; /* update pointer to head of list */

	newmatch->hasdupes = 1;
	traverse->hasdupes = 0; /* flag is only for first file in dupe chain */
      }
      else
	back->duplicates = newmatch;

      break;
    }
    else
    {
      if (traverse->duplicates == 0)
      {
	traverse->duplicates = newmatch;
	
	if (back == 0)
	  traverse->hasdupes = 1;
	
	break;
      }
    }
    
    back = traverse;
    traverse = traverse->duplicates;
  }
}

void deletesuccessor(file_t **existing, file_t *duplicate, 
      int (*comparef)(file_t *f1, file_t *f2), struct log_info *loginfo)
{
  file_t *to_keep;
  file_t *to_delete;

  if (comparef(duplicate, *existing) >= 0)
  {
    to_keep = *existing;
    to_delete = duplicate;
  }
  else
  {
    to_keep = duplicate;
    to_delete = *existing;

    *existing = duplicate;
  }

  if (!ISFLAG(flags, F_HIDEPROGRESS)) fprintf(stderr, "\r%40s\r", " ");

  printf("   [+] %s\n", to_keep->d_name);

  if (loginfo)
    log_file_remaining(loginfo, to_keep->d_name);

  if (remove(to_delete->d_name) == 0) {
    printf("   [-] %s\n", to_delete->d_name);

    if (loginfo)
      log_file_deleted(loginfo, to_delete->d_name);
  } else {
    printf("   [!] %s ", to_delete->d_name);
    printf("-- unable to delete file!\n");

    if (loginfo)
      log_file_remaining(loginfo, to_delete->d_name);
  }

  printf("\n");
}

void help_text()
{
  printf("Usage: fdupes [options] DIRECTORY...\n\n");

  printf(" -r --recurse     \tfor every directory given follow subdirectories\n");
  printf("                  \tencountered within\n");
  printf(" -R --recurse:    \tfor each directory given after this option follow\n");
  printf("                  \tsubdirectories encountered within (note the ':' at\n");
  printf("                  \tthe end of the option, manpage for more details)\n");
  printf(" -s --symlinks    \tfollow symlinks\n");
  printf(" -H --hardlinks   \tnormally, when two or more files point to the same\n");
  printf("                  \tdisk area they are treated as non-duplicates; this\n"); 
  printf("                  \toption will change this behavior\n");
  printf(" -G --minsize=SIZE\tconsider only files greater than or equal to SIZE\n");
  printf(" -L --maxsize=SIZE\tconsider only files less than or equal to SIZE\n");
  printf(" -n --noempty     \texclude zero-length files from consideration\n");
  printf(" -A --nohidden    \texclude hidden files from consideration\n");
  printf(" -f --omitfirst   \tomit the first file in each set of matches\n");
  printf(" -1 --sameline    \tlist each set of matches on a single line\n");
  printf(" -S --size        \tshow size of duplicate files\n");
  printf(" -t --time        \tshow modification time of duplicate files\n");
  printf(" -m --summarize   \tsummarize dupe information\n");
  printf(" -q --quiet       \thide progress indicator\n");
  printf(" -d --delete      \tprompt user for files to preserve and delete all\n"); 
  printf("                  \tothers; important: under particular circumstances,\n");
  printf("                  \tdata may be lost when using this option together\n");
  printf("                  \twith -s or --symlinks, or when specifying a\n");
  printf("                  \tparticular directory more than once; refer to the\n");
  printf("                  \tfdupes documentation for additional information\n");
#ifndef NO_NCURSES
  printf(" -P --plain       \twith --delete, use line-based prompt (as with older\n");
  printf("                  \tversions of fdupes) instead of screen-mode interface\n");
#endif
  printf(" -N --noprompt    \ttogether with --delete, preserve the first file in\n");
  printf("                  \teach set of duplicates and delete the rest without\n");
  printf("                  \tprompting the user\n");
  printf(" -I --immediate   \tdelete duplicates as they are encountered, without\n");
  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 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(" -l --log=LOGFILE \tlog file deletion choices to LOGFILE\n");
  printf(" -v --version     \tdisplay fdupes version\n");
  printf(" -h --help        \tdisplay this help message\n\n");
#ifndef HAVE_GETOPT_H
  printf("Note: Long options are not supported in this fdupes build.\n\n");
#endif
}

int main(int argc, char **argv) {
  int x;
  int opt;
  FILE *file1;
  FILE *file2;
  file_t *files = NULL;
  file_t *curfile;
  file_t **match = NULL;
  filetree_t *checktree = NULL;
  int filecount = 0;
  int progress = 0;
  char **oldargv;
  int firstrecurse;
  char *logfile = 0;
  struct log_info *loginfo;
  int log_error;
  struct stat logfile_status;
  char *endptr;
  
#ifdef HAVE_GETOPT_H
  static struct option long_options[] = 
  {
    { "omitfirst", 0, 0, 'f' },
    { "recurse", 0, 0, 'r' },
    { "recurse:", 0, 0, 'R' },
    { "quiet", 0, 0, 'q' },
    { "sameline", 0, 0, '1' },
    { "size", 0, 0, 'S' },
    { "time", 0, 0, 't' },
    { "symlinks", 0, 0, 's' },
    { "hardlinks", 0, 0, 'H' },
    { "minsize", 1, 0, 'G' },
    { "maxsize", 1, 0, 'L' },
    { "noempty", 0, 0, 'n' },
    { "nohidden", 0, 0, 'A' },
    { "delete", 0, 0, 'd' },
    { "plain", 0, 0, 'P' },
    { "version", 0, 0, 'v' },
    { "help", 0, 0, 'h' },
    { "noprompt", 0, 0, 'N' },
    { "immediate", 0, 0, 'I'},
    { "summarize", 0, 0, 'm'},
    { "summary", 0, 0, 'm' },
    { "permissions", 0, 0, 'p' },
    { "order", 1, 0, 'o' },
    { "reverse", 0, 0, 'i' },
    { "log", 1, 0, 'l' },
    { 0, 0, 0, 0 }
  };
#define GETOPT getopt_long
#else
#define GETOPT getopt
#endif

  program_name = argv[0];

  setlocale(LC_CTYPE, "");

  oldargv = cloneargs(argc, argv);

  while ((opt = GETOPT(argc, argv, "frRq1StsHG:L:nAdPvhNImpo:il:"
#ifdef HAVE_GETOPT_H
          , long_options, NULL
#endif
          )) != EOF) {
    switch (opt) {
    case 'f':
      SETFLAG(flags, F_OMITFIRST);
      break;
    case 'r':
      SETFLAG(flags, F_RECURSE);
      break;
    case 'R':
      SETFLAG(flags, F_RECURSEAFTER);
      break;
    case 'q':
      SETFLAG(flags, F_HIDEPROGRESS);
      break;
    case '1':
      SETFLAG(flags, F_DSAMELINE);
      break;
    case 'S':
      SETFLAG(flags, F_SHOWSIZE);
      break;
    case 't':
      SETFLAG(flags, F_SHOWTIME);
      break;
    case 's':
      SETFLAG(flags, F_FOLLOWLINKS);
      break;
    case 'H':
      SETFLAG(flags, F_CONSIDERHARDLINKS);
      break;
    case 'G':
      minsize = strtoll(optarg, &endptr, 10);
      if (optarg[0] == '\0' || *endptr != '\0' || minsize < 0)
      {
        errormsg("invalid value for --minsize: '%s'\n", optarg);
        exit(1);
      }
      break;
    case 'L':
      maxsize = strtoll(optarg, &endptr, 10);
      if (optarg[0] == '\0' || *endptr != '\0' || maxsize < 0)
      {
        errormsg("invalid value for --maxsize: '%s'\n", optarg);
        exit(1);
      }
      break;
    case 'n':
      SETFLAG(flags, F_EXCLUDEEMPTY);
      break;
    case 'A':
      SETFLAG(flags, F_EXCLUDEHIDDEN);
      break;
    case 'd':
      SETFLAG(flags, F_DELETEFILES);
      break;
    case 'P':
      SETFLAG(flags, F_PLAINPROMPT);
      break;
    case 'v':
      printf("fdupes %s\n", VERSION);
      exit(0);
    case 'h':
      help_text();
      exit(1);
    case 'N':
      SETFLAG(flags, F_NOPROMPT);
      break;
    case 'I':
      SETFLAG(flags, F_IMMEDIATE);
      break;
    case 'm':
      SETFLAG(flags, F_SUMMARIZEMATCHES);
      break;
    case 'p':
      SETFLAG(flags, F_PERMISSIONS);
      break;
    case 'o':
      if (!strcasecmp("name", optarg)) {
        ordertype = ORDER_NAME;
      } else if (!strcasecmp("time", optarg)) {
        ordertype = ORDER_MTIME;
      } else if (!strcasecmp("ctime", optarg)) {
        ordertype = ORDER_CTIME;
      } else {
        errormsg("invalid value for --order: '%s'\n", optarg);
        exit(1);
      }
      break;
    case 'i':
      SETFLAG(flags, F_REVERSE);
      break;
    case 'l':
      loginfo = log_open(logfile=optarg, &log_error);
      if (loginfo == 0)
      {
        if (log_error == LOG_ERROR_NOT_A_LOG_FILE)
          errormsg("%s: doesn't look like an fdupes log file\n", logfile);
        else
          errormsg("%s: could not open log file\n", logfile);

        exit(1);
      }
      log_close(loginfo);

      if (stat(logfile, &logfile_status) != 0)
      {
        errormsg("could not read log file status\n");
        exit(1);
      }

      break;
    default:
      fprintf(stderr, "Try `fdupes --help' for more information.\n");
      exit(1);
    }
  }

  if (optind >= argc) {
    errormsg("no directories specified\n");
    exit(1);
  }

  if (ISFLAG(flags, F_RECURSE) && ISFLAG(flags, F_RECURSEAFTER)) {
    errormsg("options --recurse and --recurse: are not compatible\n");
    exit(1);
  }

  if (ISFLAG(flags, F_SUMMARIZEMATCHES) && ISFLAG(flags, F_DELETEFILES)) {
    errormsg("options --summarize and --delete are not compatible\n");
    exit(1);
  }

  if (ISFLAG(flags, F_RECURSEAFTER)) {
    firstrecurse = nonoptafter("--recurse:", argc, oldargv, argv, optind);
    
    if (firstrecurse == argc)
      firstrecurse = nonoptafter("-R", argc, oldargv, argv, optind);

    if (firstrecurse == argc) {
      errormsg("-R option must be isolated from other options\n");
      exit(1);
    }

    /* F_RECURSE is not set for directories before --recurse: */
    for (x = optind; x < firstrecurse; x++)
      filecount += grokdir(argv[x], &files, &logfile_status);

    /* Set F_RECURSE for directories after --recurse: */
    SETFLAG(flags, F_RECURSE);

    for (x = firstrecurse; x < argc; x++)
      filecount += grokdir(argv[x], &files, &logfile_status);
  } else {
    for (x = optind; x < argc; x++)
      filecount += grokdir(argv[x], &files, &logfile_status);
  }

  if (!files) {
    if (!ISFLAG(flags, F_HIDEPROGRESS)) fprintf(stderr, "\r%40s\r", " ");
    exit(0);
  }
  
  curfile = files;

  while (curfile) {
    if (!checktree) 
      registerfile(&checktree, curfile);
    else 
      match = checkmatch(&checktree, checktree, curfile);

    if (match != NULL) {
      file1 = fopen(curfile->d_name, "rb");
      if (!file1) {
	curfile = curfile->next;
	continue;
      }
      
      file2 = fopen((*match)->d_name, "rb");
      if (!file2) {
	fclose(file1);
	curfile = curfile->next;
	continue;
      }

      if (confirmmatch(file1, file2)) {
        if (ISFLAG(flags, F_DELETEFILES) && ISFLAG(flags, F_IMMEDIATE))
          deletesuccessor(match, curfile,
              (ordertype == ORDER_MTIME || 
               ordertype == ORDER_CTIME) ? sort_pairs_by_time : sort_pairs_by_filename, loginfo );
        else
          registerpair(match, curfile,
              (ordertype == ORDER_MTIME ||
               ordertype == ORDER_CTIME) ? sort_pairs_by_time : sort_pairs_by_filename );
      }
      
      fclose(file1);
      fclose(file2);
    }

    curfile = curfile->next;

    if (!ISFLAG(flags, F_HIDEPROGRESS)) {
      fprintf(stderr, "\rProgress [%d/%d] %d%% ", progress, filecount,
       (int)((float) progress / (float) filecount * 100.0));
      progress++;
    }
  }

  if (!ISFLAG(flags, F_HIDEPROGRESS)) fprintf(stderr, "\r%40s\r", " ");

  if (ISFLAG(flags, F_DELETEFILES))
  {
    if (ISFLAG(flags, F_NOPROMPT))
    {
      deletefiles(files, 0, 0, logfile);
    }
    else
    {
#ifndef NO_NCURSES
      if (!ISFLAG(flags, F_PLAINPROMPT))
      {
        if (newterm(getenv("TERM"), stdout, stdin) != 0)
        {
          deletefiles_ncurses(files, logfile);
        }
        else
        {
          errormsg("could not enter screen mode; falling back to plain mode\n\n");
          SETFLAG(flags, F_PLAINPROMPT);
        }
      }

      if (ISFLAG(flags, F_PLAINPROMPT))
      {
        if (freopen("/dev/tty", "r", stdin) == NULL)
        {
          errormsg("could not open terminal for input\n");
          exit(1);
        }

        deletefiles(files, 1, stdin, logfile);
      }
#else
      if (freopen("/dev/tty", "r", stdin) == NULL)
      {
        errormsg("could not open terminal for input\n");
        exit(1);
      }

      deletefiles(files, 1, stdin, logfile);
#endif
    }
  }

  else 

    if (ISFLAG(flags, F_SUMMARIZEMATCHES))
      summarizematches(files);
      
    else

      printmatches(files);

  while (files) {
    curfile = files->next;
    free(files->d_name);
    free(files->crcsignature);
    free(files->crcpartial);
    free(files);
    files = curfile;
  }

  for (x = 0; x < argc; x++)
    free(oldargv[x]);

  free(oldargv);

  purgetree(checktree);

  return 0;
}