lziprecover/trailing_data.cc

/*  Lziprecover - Data recovery tool for the lzip format
    Copyright (C) 2009-2018 Antonio Diaz Diaz.

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 2 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#define _FILE_OFFSET_BITS 64

#include <cerrno>
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
#include <stdint.h>
#include <unistd.h>
#include <utime.h>
#include <sys/stat.h>

#include "lzip.h"
#include "block.h"
#include "file_index.h"


int dump_tdata( const std::vector< std::string > & filenames,
                const std::string & default_output_filename, const bool force,
                const bool strip, const bool loose_trailing )
  {
  if( default_output_filename.empty() ) outfd = STDOUT_FILENO;
  else
    {
    output_filename = default_output_filename;
    if( !open_outstream( force, true, false, false ) ) return 1;
    }
  unsigned long long total_size = 0;
  int files = 0, retval = 0;
  bool stdin_used = false;
  for( unsigned i = 0; i < filenames.size(); ++i )
    {
    const bool from_stdin = ( filenames[i] == "-" );
    if( from_stdin ) { if( stdin_used ) continue; else stdin_used = true; }
    const char * const input_filename =
      from_stdin ? "(stdin)" : filenames[i].c_str();
    struct stat in_stats;				// not used
    const int infd = from_stdin ? STDIN_FILENO :
      open_instream( input_filename, &in_stats, true, true );
    if( infd < 0 ) { if( retval < 1 ) retval = 1; continue; }

    const File_index file_index( infd, false, true, loose_trailing );
    if( file_index.retval() != 0 )
      {
      show_file_error( input_filename, file_index.error().c_str() );
      if( retval < file_index.retval() ) retval = file_index.retval();
      close( infd );
      continue;
      }
    const unsigned long long cdata_size = file_index.cdata_size();
    const long long trailing_size = file_index.file_size() - cdata_size;
    if( strip )
      {
      total_size += cdata_size; ++files;
      if( !safe_seek( infd, 0 ) || !copy_file( infd, outfd, cdata_size ) )
        cleanup_and_fail( 1 );
      }
    else if( trailing_size > 0 )
      {
      total_size += trailing_size; ++files;
      if( !safe_seek( infd, cdata_size ) || !copy_file( infd, outfd ) )
        cleanup_and_fail( 1 );
      }
    close( infd );
    }
  if( verbosity >= 1 )
    {
    if( strip )
      std::fprintf( stderr, "%llu bytes copied from %d file(s).\n",
                    total_size, files );
    else
      std::fprintf( stderr, "%llu trailing bytes dumped from %d file(s).\n",
                    total_size, files );
    }
  if( close_outstream( 0 ) != 0 ) return 1;
  return retval;
  }


int remove_tdata( const std::vector< std::string > & filenames,
                  const bool loose_trailing )
  {
  unsigned long long total_size = 0;
  int files = 0, retval = 0;
  for( unsigned i = 0; i < filenames.size(); ++i )
    {
    const char * const filename = filenames[i].c_str();
    struct stat in_stats;
    const int infd = open_truncable_stream( filename, &in_stats );
    if( infd < 0 ) { if( retval < 1 ) retval = 1; continue; }

    const File_index file_index( infd, false, true, loose_trailing );
    if( file_index.retval() != 0 )
      {
      show_file_error( filename, file_index.error().c_str() );
      if( retval < file_index.retval() ) retval = file_index.retval();
      close( infd );
      continue;
      }
    const unsigned long long cdata_size = file_index.cdata_size();
    const long long trailing_size = file_index.file_size() - cdata_size;
    if( trailing_size > 0 )
      {
      int i;
      do i = ftruncate( infd, cdata_size );
        while( i != 0 && errno == EINTR );
      if( i == 0 )
        {
        struct utimbuf t;
        t.actime = in_stats.st_atime;
        t.modtime = in_stats.st_mtime;
        utime( filename, &t );
        total_size += trailing_size; ++files;
        }
      else
        {
        show_file_error( filename, "Can't truncate file", errno );
        if( retval < 1 ) retval = 1;
        }
      }
    close( infd );
    }
  if( verbosity >= 1 )
    std::fprintf( stderr, "%llu trailing bytes removed from %d file(s).\n",
                  total_size, files );
  return retval;
  }