Merging upstream version 1.11.

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

1 files changed, 556 insertions, 57 deletions

diff --git a/lziprecover.cc b/lziprecover.cc
index 3acd46c..3f1b130 100644
--- a/lziprecover.cc
+++ b/lziprecover.cc
@@ -1,4 +1,4 @@
-/*  Lziprecover - Member recoverer program for lzip compressed files
+/*  Lziprecover - Data recovery tool for lzip compressed files
     Copyright (C) 2008, 2009, 2010 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
@@ -23,7 +23,9 @@
 
 #define _FILE_OFFSET_BITS 64
 
+#include <algorithm>
 #include <cerrno>
+#include <climits>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
@@ -33,9 +35,30 @@
 #include <stdint.h>
 #include <unistd.h>
 #include <sys/stat.h>
+#if defined(__MSVCRT__)
+#define S_IRGRP 0
+#define S_IWGRP 0
+#define S_IROTH 0
+#define S_IWOTH 0
+#endif
 
 #include "arg_parser.h"
 #include "lzip.h"
+#include "decoder.h"
+
+#if CHAR_BIT != 8
+#error "Environments where CHAR_BIT != 8 are not supported."
+#endif
+
+#ifndef LLONG_MAX
+#define LLONG_MAX  0x7FFFFFFFFFFFFFFFLL
+#endif
+#ifndef LLONG_MIN
+#define LLONG_MIN  (-LLONG_MAX - 1LL)
+#endif
+#ifndef ULLONG_MAX
+#define ULLONG_MAX 0xFFFFFFFFFFFFFFFFULL
+#endif
 
 
 namespace {
@@ -51,18 +74,43 @@ const int o_binary = O_BINARY;
 const int o_binary = 0;
 #endif
 
+int verbosity = 0;
+
+
+class Block
+  {
+  long long pos_, size_;		// pos + size <= LLONG_MAX
+
+public:
+  Block( const long long p, const long long s ) throw()
+    : pos_( p ), size_( s ) {}
+
+  long long pos() const throw() { return pos_; }
+  long long size() const throw() { return size_; }
+  long long end() const throw() { return pos_ + size_; }
+
+  void pos( const long long p ) throw() { pos_ = p; }
+  void size( const long long s ) throw() { size_ = s; }
+  void shift( Block & b ) throw() { ++size_; ++b.pos_; --b.size_; }
+  };
+
 
 void show_help() throw()
   {
-  std::printf( "%s - Member recoverer program for lzip compressed files.\n", Program_name );
-  std::printf( "\nSearches for members in .lz files, and writes each member in its own .lz\n" );
-  std::printf( "file. You can then use `lzip -t' to test the integrity of the resulting\n" );
-  std::printf( "files, and decompress those which are undamaged.\n" );
-  std::printf( "\nUsage: %s [options] file\n", invocation_name );
-  std::printf( "Options:\n" );
+  std::printf( "%s - Data recovery tool for lzip compressed files.\n", Program_name );
+  std::printf( "\nUsage: %s [options] [files]\n", invocation_name );
+  std::printf( "\nOptions:\n" );
   std::printf( "  -h, --help                 display this help and exit\n" );
   std::printf( "  -V, --version              output version information and exit\n" );
+//  std::printf( "  -c, --create-recover-file  create a recover file\n" );
+  std::printf( "  -f, --force                overwrite existing output files\n" );
+  std::printf( "  -m, --merge                correct errors in file using several copies\n" );
+  std::printf( "  -o, --output=<file>        place the output into <file>\n" );
   std::printf( "  -q, --quiet                suppress all messages\n" );
+//  std::printf( "  -r, --recover              correct errors in file using a recover file\n" );
+  std::printf( "  -R, --repair               try to repair a small error in file\n" );
+  std::printf( "  -s, --split                split a multimember file in single-member files\n" );
+//  std::printf( "  -u, --update               convert file from version 0 to version 1\n" );
   std::printf( "  -v, --verbose              be verbose (a 2nd -v gives more)\n" );
   std::printf( "\nReport bugs to lzip-bug@nongnu.org\n");
   std::printf( "Lzip home page: http://www.nongnu.org/lzip/lzip.html\n" );
@@ -95,7 +143,7 @@ int open_instream( const std::string & input_filename ) throw()
     if( i < 0 || !S_ISREG( in_stats.st_mode ) )
       {
       if( verbosity >= 0 )
-        std::fprintf( stderr, "%s: input file `%s' is not a regular file.\n",
+        std::fprintf( stderr, "%s: Input file `%s' is not a regular file.\n",
                       program_name, input_filename.c_str() );
       close( infd );
       infd = -1;
@@ -105,14 +153,21 @@ int open_instream( const std::string & input_filename ) throw()
   }
 
 
-int open_outstream( const std::string & output_filename ) throw()
+int open_outstream( const std::string & output_filename,
+                    const bool force ) throw()
   {
-  int outfd = open( output_filename.c_str(),
-                    O_CREAT | O_TRUNC | O_WRONLY | o_binary,
+  int flags = O_CREAT | O_RDWR | o_binary;
+  if( force ) flags |= O_TRUNC; else flags |= O_EXCL;
+
+  int outfd = open( output_filename.c_str(), flags,
                     S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH );
-  if( outfd < 0 )
+  if( outfd < 0 && verbosity >= 0 )
     {
-    if( verbosity >= 0 )
+    if( errno == EEXIST )
+      std::fprintf( stderr, "%s: Output file `%s' already exists."
+                            " Use `--force' to overwrite it.\n",
+                    program_name, output_filename.c_str() );
+    else
       std::fprintf( stderr, "%s: Can't create output file `%s': %s.\n",
                     program_name, output_filename.c_str(), std::strerror( errno ) );
     }
@@ -120,36 +175,22 @@ int open_outstream( const std::string & output_filename ) throw()
   }
 
 
-bool next_filename( std::string & output_filename )
-  {
-  for( int i = 7; i >= 3; --i )			// "rec00001"
-    {
-    if( output_filename[i] < '9' ) { ++output_filename[i]; return true; }
-    else output_filename[i] = '0';
-    }
-  return false;
-  }
-
-
-bool verify_header( const uint8_t * const buffer, const int pos )
+bool verify_header( const File_header & header )
   {
-  File_header header;
-  for( int i = 0; i < File_header::size; ++i )
-    header.data[i] = buffer[pos+i];
   if( !header.verify_magic() )
     {
-    show_error( "bad magic number (file not in lzip format).\n" );
+    show_error( "Bad magic number (file not in lzip format)." );
     return false;
     }
   if( header.version() == 0 )
     {
-    show_error( "version 0 member format can't be recovered.\n" );
+    show_error( "Version 0 member format can't be recovered." );
     return false;
     }
   if( header.version() != 1 )
     {
     if( verbosity >= 0 )
-      std::fprintf( stderr, "version %d member format not supported, newer %s needed.\n",
+      std::fprintf( stderr, "Version %d member format not supported, newer %s needed.\n",
                     header.version(), program_name );
     return false;
     }
@@ -157,7 +198,396 @@ bool verify_header( const uint8_t * const buffer, const int pos )
   }
 
 
-int process_file( const std::string & input_filename, uint8_t * & base_buffer )
+bool verify_single_member( const int fd, const long long file_size )
+  {
+  File_header header;
+  if( lseek( fd, 0, SEEK_SET ) < 0 ||
+      readblock( fd, header.data, File_header::size ) != File_header::size )
+    { show_error( "Error reading member header", errno ); return false; }
+  if( !verify_header( header ) ) return false;
+
+  File_trailer trailer;
+  if( lseek( fd, -File_trailer::size(), SEEK_END ) < 0 ||
+      readblock( fd, trailer.data, File_trailer::size() ) != File_trailer::size() )
+    { show_error( "Error reading member trailer", errno ); return false; }
+  const long long member_size = trailer.member_size();
+  if( member_size != file_size )
+    {
+    if( member_size < file_size &&
+        lseek( fd, -member_size, SEEK_END ) > 0 &&
+        readblock( fd, header.data, File_header::size ) == File_header::size &&
+        verify_header( header ) )
+      show_error( "Input file has more than 1 member. Split it first." );
+    else
+      show_error( "Member size in input file trailer is corrupt." );
+    return false;
+    }
+  return true;
+  }
+
+
+bool try_decompress( const int fd, const long long file_size,
+                     long long * failure_pos = 0 )
+  {
+  try {
+    Range_decoder rdec( fd );
+    File_header header;
+    rdec.reset_member_position();
+    for( int i = 0; i < File_header::size; ++i )
+      header.data[i] = rdec.get_byte();
+    if( !rdec.finished() &&			// End Of File
+        header.verify_magic() &&
+        header.version() == 1 &&
+        header.dictionary_size() >= min_dictionary_size &&
+          header.dictionary_size() <= max_dictionary_size )
+      {
+      LZ_decoder decoder( header, rdec, -1 );
+      std::vector< std::string > dummy_filenames;
+      Pretty_print dummy( dummy_filenames, -1 );
+
+      if( decoder.decode_member( dummy ) == 0 &&
+          rdec.member_position() == file_size ) return true;
+      if( failure_pos ) *failure_pos = rdec.member_position();
+      }
+    }
+  catch( std::bad_alloc )
+    {
+    show_error( "Not enough memory. Find a machine with more memory." );
+    std::exit( 1 );
+    }
+  catch( Error e ) {}
+  return false;
+  }
+
+
+bool copy_and_diff_file( const std::vector< int > & infd_vector,
+                         const int outfd, std::vector< Block > & block_vector )
+  {
+  const int buffer_size = 65536;
+  std::vector< uint8_t * > buffer_vector( infd_vector.size() );
+  for( unsigned int i = 0; i < infd_vector.size(); ++i )
+    buffer_vector[i] = new uint8_t[buffer_size];
+  Block b( 0, 0 );
+  long long partial_pos = 0;
+  int equal_bytes = 0;
+  bool error = false;
+
+  while( !error )
+    {
+    const int rd = readblock( infd_vector[0], buffer_vector[0], buffer_size );
+    if( rd != buffer_size && errno )
+      { show_error( "Error reading input file", errno ); error = true; }
+    if( rd > 0 )
+      {
+      for( unsigned int i = 1; i < infd_vector.size(); ++i )
+        if( readblock( infd_vector[i], buffer_vector[i], rd ) != rd )
+          { show_error( "Error reading input file", errno ); error = true; }
+      const int wr = writeblock( outfd, buffer_vector[0], rd );
+      if( wr != rd )
+        { show_error( "Error writing output file", errno ); error = true; }
+      for( int i = 0; i < rd; ++i )
+        {
+        while( i < rd && b.pos() == 0 )
+          {
+          for( unsigned int j = 1; j < infd_vector.size(); ++j )
+            if( buffer_vector[0][i] != buffer_vector[j][i] )
+              { b.pos( partial_pos + i ); break; }	// begin block
+          ++i;
+          }
+        while( i < rd && b.pos() > 0 )
+          {
+          ++equal_bytes;
+          for( unsigned int j = 1; j < infd_vector.size(); ++j )
+            if( buffer_vector[0][i] != buffer_vector[j][i] )
+              { equal_bytes = 0; break; }
+          if( equal_bytes >= 2 )			// end block
+            {
+            b.size( partial_pos + i - ( equal_bytes - 1 ) - b.pos() );
+            block_vector.push_back( b );
+            b.pos( 0 );
+            equal_bytes = 0;
+            }
+          ++i;
+          }
+        }
+      partial_pos += rd;
+      }
+    if( rd < buffer_size ) break;			// EOF
+    }
+  if( b.pos() > 0 )					// finish last block
+    {
+    b.size( partial_pos - b.pos() );
+    block_vector.push_back( b );
+    }
+  for( unsigned int i = 0; i < infd_vector.size(); ++i )
+    delete[] buffer_vector[i];
+  return !error;
+  }
+
+
+bool copy_file( const int infd, const int outfd,
+                const long long size = LLONG_MAX )
+  {
+  long long rest = size;
+  const int buffer_size = 65536;
+  uint8_t * const buffer = new uint8_t[buffer_size];
+  bool error = false;
+
+  while( !error )
+    {
+    const int block_size = std::min( (long long)buffer_size, rest );
+    if( block_size <= 0 ) break;
+    const int rd = readblock( infd, buffer, block_size );
+    if( rd != block_size && errno )
+      { show_error( "Error reading input file", errno ); error = true; }
+    if( rd > 0 )
+      {
+      const int wr = writeblock( outfd, buffer, rd );
+      if( wr != rd )
+        { show_error( "Error writing output file", errno ); error = true; }
+      rest -= rd;
+      }
+    if( rd < block_size ) break;			// EOF
+    }
+  delete[] buffer;
+  return !error;
+  }
+
+
+std::string insert_fixed( std::string name ) throw()
+  {
+  if( name.size() > 4 && name.compare( name.size() - 4, 4, ".tlz" ) == 0 )
+    name.insert( name.size() - 4, "_fixed" );
+  else if( name.size() > 3 && name.compare( name.size() - 3, 3, ".lz" ) == 0 )
+    name.insert( name.size() - 3, "_fixed" );
+  else name += "_fixed.lz";
+  return name;
+  }
+
+
+int ipow( const unsigned int base, const unsigned int exponent ) throw()
+  {
+  int result = 1;
+  for( unsigned int i = 0; i < exponent; ++i )
+    {
+    if( INT_MAX / base >= (unsigned int)result ) result *= base;
+    else { result = INT_MAX; break; }
+    }
+  return result;
+  }
+
+
+int merge_files( const std::vector< std::string > & filenames,
+                 const std::string & output_filename, const bool force )
+  {
+  std::vector< int > infd_vector( filenames.size() );
+  for( unsigned int i = 0; i < filenames.size(); ++i )
+    {
+    infd_vector[i] = open_instream( filenames[i] );
+    if( infd_vector[i] < 0 ) return 1;
+    }
+  long long isize = 0;
+  for( unsigned int i = 0; i < filenames.size(); ++i )
+    {
+    const long long tmp = lseek( infd_vector[i], 0, SEEK_END );
+    if( tmp < 0 )
+      {
+      if( verbosity >= 0 )
+        std::fprintf( stderr, "File `%s' is not seekable.\n", filenames[i].c_str() );
+      return 1;
+      }
+    if( i == 0 ) isize = tmp;
+    else if( isize != tmp )
+      { show_error( "Sizes of input files are different." ); return 1; }
+    }
+  if( isize < 36 )
+    { show_error( "Input file is too short." ); return 2; }
+  for( unsigned int i = 0; i < filenames.size(); ++i )
+    if( !verify_single_member( infd_vector[i], isize ) )
+      return 2;
+  for( unsigned int i = 0; i < filenames.size(); ++i )
+    if( lseek( infd_vector[i], 0, SEEK_SET ) < 0 )
+      { show_error( "Seek error in input file", errno ); return 1; }
+  for( unsigned int i = 0; i < filenames.size(); ++i )
+    if( try_decompress( infd_vector[i], isize ) )
+      {
+      if( verbosity >= 0 )
+        std::printf( "File `%s' has no errors. Recovery is not needed.\n",
+                     filenames[i].c_str() );
+      return 0;
+      }
+
+  const int outfd = open_outstream( output_filename, force );
+  if( outfd < 0 ) return 1;
+  for( unsigned int i = 0; i < filenames.size(); ++i )
+    if( lseek( infd_vector[i], 0, SEEK_SET ) < 0 )
+      { show_error( "Seek error in input file", errno ); return 1; }
+
+  // vector of data blocks differing among the copies of the input file.
+  std::vector< Block > block_vector;
+  if( !copy_and_diff_file( infd_vector, outfd, block_vector ) ) return 1;
+
+  if( !block_vector.size() )
+    { show_error( "Input files are identical. Recovery is not possible." );
+      return 1; }
+
+  const bool single_block = ( block_vector.size() == 1 );
+  if( single_block && block_vector[0].size() < 2 )
+    { show_error( "Input files have the same byte damaged."
+                  " Try repairing one of them." );
+      return 1; }
+
+  if( ipow( filenames.size(), block_vector.size() ) >= INT_MAX ||
+      ( single_block &&
+        ipow( filenames.size(), 2 ) >= INT_MAX / block_vector[0].size() ) )
+    { show_error( "Input files are too damaged. Recovery is not possible." );
+      return 1; }
+
+  const int shifts = ( single_block ? block_vector[0].size() - 1 : 1 );
+  if( single_block )
+    {
+    Block b( block_vector[0].pos() + 1, block_vector[0].size() - 1 );
+    block_vector[0].size( 1 );
+    block_vector.push_back( b );
+    }
+
+  const int base_variations = ipow( filenames.size(), block_vector.size() );
+  const int variations = ( base_variations * shifts ) - 2;
+  bool done = false;
+  for( int var = 1; var <= variations; ++var )
+    {
+    if( verbosity >= 0 )
+      {
+      std::printf( "Trying variation %d of %d \r", var, variations );
+      std::fflush( stdout );
+      }
+    int tmp = var;
+    for( unsigned int i = 0; i < block_vector.size(); ++i )
+      {
+      const int infd = infd_vector[tmp % filenames.size()];
+      tmp /= filenames.size();
+      if( lseek( infd, block_vector[i].pos(), SEEK_SET ) < 0 ||
+          lseek( outfd, block_vector[i].pos(), SEEK_SET ) < 0 ||
+          !copy_file( infd, outfd, block_vector[i].size() ) )
+        { show_error( "Error reading output file", errno ); return 1; }
+      }
+    if( lseek( outfd, 0, SEEK_SET ) < 0 )
+      { show_error( "Seek error in output file", errno ); return 1; }
+    if( try_decompress( outfd, isize ) )
+      { done = true; break; }
+    if( var % base_variations == 0 ) block_vector[0].shift( block_vector[1] );
+    }
+  if( verbosity >= 0 ) std::printf( "\n" );
+
+  if( close( outfd ) != 0 )
+    { show_error( "Error closing output file", errno ); return 1; }
+  if( done )
+    {
+    if( verbosity >= 0 )
+      std::printf( "Input files merged successfully.\n" );
+    return 0;
+    }
+  else
+    {
+    std::remove( output_filename.c_str() );
+    show_error( "Some error areas overlap. Can't recover input file." );
+    return 2;
+    }
+  }
+
+
+int repair_file( const std::string & input_filename,
+                 const std::string & output_filename, const bool force )
+  {
+  const int infd = open_instream( input_filename );
+  if( infd < 0 ) return 1;
+  const long long isize = lseek( infd, 0, SEEK_END );
+  if( isize < 0 )
+    { show_error( "Input file is not seekable", errno ); return 1; }
+  if( isize < 36 )
+    { show_error( "Input file is too short." ); return 2; }
+  if( !verify_single_member( infd, isize ) ) return 2;
+  if( lseek( infd, 0, SEEK_SET ) < 0 )
+    { show_error( "Seek error in input file", errno ); return 1; }
+  long long failure_pos = 0;
+  if( try_decompress( infd, isize, &failure_pos ) )
+    {
+    if( verbosity >= 0 )
+      std::printf( "Input file has no errors. Recovery is not needed.\n" );
+    return 0;
+    }
+  if( failure_pos >= isize - 8 ) failure_pos = isize - 8 - 1;
+  if( failure_pos < File_header::size )
+    { show_error( "Can't repair error in input file." ); return 2; }
+
+  const int outfd = open_outstream( output_filename, force );
+  if( outfd < 0 ) { close( infd ); return 1; }
+  if( lseek( infd, 0, SEEK_SET ) < 0 )
+    { show_error( "Seek error in input file", errno ); return 1; }
+  if( !copy_file( infd, outfd ) ) return 1;
+
+  const long long min_pos =
+    std::max( (long long)File_header::size, failure_pos - 1000 );
+  bool done = false;
+  for( long long pos = failure_pos; pos >= min_pos; --pos )
+    {
+    if( verbosity >= 0 )
+      {
+      std::printf( "Trying position %lld \r", pos );
+      std::fflush( stdout );
+      }
+    uint8_t byte;
+    if( lseek( outfd, pos, SEEK_SET ) < 0 ||
+        readblock( outfd, &byte, 1 ) != 1 )
+      { show_error( "Error reading output file", errno ); return 1; }
+    for( int i = 0; i < 255; ++i )
+      {
+      ++byte;
+      if( lseek( outfd, pos, SEEK_SET ) < 0 ||
+          writeblock( outfd, &byte, 1 ) != 1 ||
+          lseek( outfd, 0, SEEK_SET ) < 0 )
+        { show_error( "Error writing output file", errno ); return 1; }
+      if( try_decompress( outfd, isize ) )
+        { done = true; break; }
+      }
+    if( done ) break;
+    ++byte;
+    if( lseek( outfd, pos, SEEK_SET ) < 0 ||
+        writeblock( outfd, &byte, 1 ) != 1 )
+      { show_error( "Error writing output file", errno ); return 1; }
+    }
+  if( verbosity >= 0 ) std::printf( "\n" );
+
+  if( close( outfd ) != 0 )
+    { show_error( "Error closing output file", errno ); return 1; }
+  if( done )
+    {
+    if( verbosity >= 0 )
+      std::printf( "Copy of input file repaired successfully.\n" );
+    return 0;
+    }
+  else
+    {
+    std::remove( output_filename.c_str() );
+    show_error( "Error is larger than 1 byte. Can't repair input file." );
+    return 2;
+    }
+  }
+
+
+bool next_filename( std::string & output_filename )
+  {
+  for( int i = 7; i >= 3; --i )			// "rec00001"
+    {
+    if( output_filename[i] < '9' ) { ++output_filename[i]; return true; }
+    else output_filename[i] = '0';
+    }
+  return false;
+  }
+
+
+int do_split_file( const std::string & input_filename, uint8_t * & base_buffer,
+                   const std::string & default_output_filename, const bool force )
   {
   const int hsize = File_header::size;
   const int tsize = File_trailer::size();
@@ -171,13 +601,17 @@ int process_file( const std::string & input_filename, uint8_t * & base_buffer )
   int size = readblock( infd, buffer, buffer_size + hsize ) - hsize;
   bool at_stream_end = ( size < buffer_size );
   if( size != buffer_size && errno )
-    { show_error( "read error", errno ); return 1; }
+    { show_error( "Read error", errno ); return 1; }
   if( size <= tsize )
-    { show_error( "file too short" ); return 2; }
-  if( !verify_header( buffer, 0 ) ) return 2;
+    { show_error( "Input file is too short." ); return 2; }
+  File_header header;
+  for( int i = 0; i < File_header::size; ++i )
+    header.data[i] = buffer[i];
+  if( !verify_header( header ) ) return 2;
 
-  std::string output_filename( "rec00001" ); output_filename += input_filename;
-  int outfd = open_outstream( output_filename );
+  std::string output_filename( "rec00001" );
+  output_filename += default_output_filename;
+  int outfd = open_outstream( output_filename, force );
   if( outfd < 0 ) { close( infd ); return 1; }
 
   long long partial_member_size = 0;
@@ -197,12 +631,12 @@ int process_file( const std::string & input_filename, uint8_t * & base_buffer )
           {						// header found
           const int wr = writeblock( outfd, buffer + pos, newpos - pos );
           if( wr != newpos - pos )
-            { show_error( "write error", errno ); return 1; }
+            { show_error( "Write error", errno ); return 1; }
           if( close( outfd ) != 0 )
-            { show_error( "error closing output file", errno ); return 1; }
+            { show_error( "Error closing output file", errno ); return 1; }
           if( !next_filename( output_filename ) )
-            { show_error( "too many members in file" ); close( infd ); return 1; }
-          outfd = open_outstream( output_filename );
+            { show_error( "Too many members in file." ); close( infd ); return 1; }
+          outfd = open_outstream( output_filename, force );
           if( outfd < 0 ) { close( infd ); return 1; }
           partial_member_size = 0;
           pos = newpos;
@@ -213,7 +647,7 @@ int process_file( const std::string & input_filename, uint8_t * & base_buffer )
       {
       const int wr = writeblock( outfd, buffer + pos, size + hsize - pos );
       if( wr != size + hsize - pos )
-        { show_error( "write error", errno ); return 1; }
+        { show_error( "Write error", errno ); return 1; }
       break;
       }
     if( pos < buffer_size )
@@ -221,46 +655,72 @@ int process_file( const std::string & input_filename, uint8_t * & base_buffer )
       partial_member_size += buffer_size - pos;
       const int wr = writeblock( outfd, buffer + pos, buffer_size - pos );
       if( wr != buffer_size - pos )
-        { show_error( "write error", errno ); return 1; }
+        { show_error( "Write error", errno ); return 1; }
       }
     std::memcpy( base_buffer, base_buffer + buffer_size, tsize + hsize );
     size = readblock( infd, buffer + hsize, buffer_size );
     at_stream_end = ( size < buffer_size );
     if( size != buffer_size && errno )
-      { show_error( "read error", errno ); return 1; }
+      { show_error( "Read error", errno ); return 1; }
     }
   close( infd );
   if( close( outfd ) != 0 )
-    { show_error( "error closing output file", errno ); return 1; }
+    { show_error( "Error closing output file", errno ); return 1; }
   return 0;
   }
 
+
+int split_file( const std::string & input_filename,
+                const std::string & default_output_filename, const bool force )
+  {
+  uint8_t * base_buffer;
+  const int retval = do_split_file( input_filename, base_buffer,
+                                    default_output_filename, force );
+  delete[] base_buffer;
+  return retval;
+  }
+
 } // end namespace
 
 
-int verbosity = 0;
+void Pretty_print::operator()( const char * const msg ) const throw()
+  {
+  if( verbosity_ >= 0 )
+    {
+    if( first_post )
+      {
+      first_post = false;
+      std::fprintf( stderr, "  %s: ", name_.c_str() );
+      for( unsigned int i = 0; i < longest_name - name_.size(); ++i )
+        std::fprintf( stderr, " " );
+      if( !msg ) std::fflush( stderr );
+      }
+    if( msg ) std::fprintf( stderr, "%s.\n", msg );
+    }
+  }
 
 
 void show_error( const char * const msg, const int errcode, const bool help ) throw()
   {
   if( verbosity >= 0 )
     {
-    if( msg && msg[0] != 0 )
+    if( msg && msg[0] )
       {
       std::fprintf( stderr, "%s: %s", program_name, msg );
-      if( errcode > 0 ) std::fprintf( stderr, ": %s", std::strerror( errcode ) );
+      if( errcode > 0 )
+        std::fprintf( stderr, ": %s", std::strerror( errcode ) );
       std::fprintf( stderr, "\n" );
       }
-    if( help && invocation_name && invocation_name[0] != 0 )
-      std::fprintf( stderr, "Try `%s --help' for more information.\n", invocation_name );
+    if( help && invocation_name && invocation_name[0] )
+      std::fprintf( stderr, "Try `%s --help' for more information.\n",
+                    invocation_name );
     }
   }
 
 
 void internal_error( const char * const msg )
   {
-  std::string s( "internal error: " ); s += msg;
-  show_error( s.c_str() );
+  std::fprintf( stderr, "%s: internal error: %s.\n", program_name, msg );
   std::exit( 3 );
   }
 
@@ -304,12 +764,22 @@ int writeblock( const int fd, const uint8_t * const buf, const int size ) throw(
 
 int main( const int argc, const char * const argv[] )
   {
+  enum Mode
+    { m_none, m_create, m_merge, m_recover, m_repair, m_split, m_update };
+  Mode program_mode = m_none;
+  bool force = false;
+  std::string default_output_filename;
   invocation_name = argv[0];
 
   const Arg_parser::Option options[] =
     {
+    { 'f', "force",           Arg_parser::no  },
     { 'h', "help",            Arg_parser::no  },
+    { 'm', "merge",           Arg_parser::no  },
+    { 'o', "output",          Arg_parser::yes },
     { 'q', "quiet",           Arg_parser::no  },
+    { 'R', "repair",          Arg_parser::no  },
+    { 's', "split",           Arg_parser::no  },
     { 'v', "verbose",         Arg_parser::no  },
     { 'V', "version",         Arg_parser::no  },
     {  0 ,  0,                Arg_parser::no  } };
@@ -325,20 +795,49 @@ int main( const int argc, const char * const argv[] )
     if( !code ) break;					// no more options
     switch( code )
       {
+      case 'f': force = true; break;
       case 'h': show_help(); return 0;
+      case 'm': program_mode = m_merge; break;
+      case 'o': default_output_filename = parser.argument( argind ); break;
       case 'q': verbosity = -1; break;
+      case 'R': program_mode = m_repair; break;
+      case 's': program_mode = m_split; break;
       case 'v': if( verbosity < 4 ) ++verbosity; break;
       case 'V': show_version(); return 0;
       default : internal_error( "uncaught option" );
       }
     }
 
+  if( program_mode == m_merge )
+    {
+    std::vector< std::string > filenames;
+    for( ; argind < parser.arguments(); ++argind )
+      filenames.push_back( parser.argument( argind ) );
+    if( filenames.size() < 2 )
+      { show_error( "You must specify at least 2 files.", 0, true ); return 1; }
+    if( !default_output_filename.size() )
+      default_output_filename = insert_fixed( filenames[0] );
+    return merge_files( filenames, default_output_filename, force );
+    }
+
   if( argind + 1 != parser.arguments() )
-    { show_error( "you must specify exactly 1 file", 0, true ); return 1; }
+    { show_error( "You must specify exactly 1 file.", 0, true ); return 1; }
 
-  uint8_t * base_buffer;
-  const int retval = process_file( parser.argument( argind ), base_buffer );
+  if( program_mode == m_repair )
+    {
+    if( !default_output_filename.size() )
+      default_output_filename = insert_fixed( parser.argument( argind ) );
+    return repair_file( parser.argument( argind ), default_output_filename, force );
+    }
 
-  delete[] base_buffer;
-  return retval;
+  if( program_mode == m_split )
+    {
+    if( !default_output_filename.size() )
+      default_output_filename = parser.argument( argind );
+    return split_file( parser.argument( argind ), default_output_filename, force );
+    }
+
+  show_error( "You must specify the operation to be performed on file.",
+              0, true );
+  return 1;
   }